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Publishing Date: 01 April, 2017 AGROBIOS NEWSLETTER

4 VOL. NO. XV, ISSUE NO. 11

18. Agronomic Practices used in Saving of Water ................ 31 Dr. R. Prakash

19. Global Warming and Crop Production ............................ 32 Indu Bala Sethi and Mahesh Jajoria

20. Agronomic Practices for Higher Production of Cotton .......................................................................... 34 Dr. Karmal Singh, Dr. A. K. Dhaka and Dr. Bhagat Singh

21. Conservation Tillage: A Potential Solution to Reduce Soil Erosion ...................................................... 35 Shinde D. B.

CROP ECOLOGY 22. Major Air Pollutants and their Effect on

Vegetation .................................................................... 36 A. Daripa and S. Chattaraj

CROP PHYSIOLOGY 23. Screening of Plants for Abiotic Stress:

Physiological and Biochemical Approaches ................... 37 K. Suresh, S. Sree Ganesh, Manish B. Patil and K. Satish

24. Drought and Drought Management Strategies ................ 39 Aradhana Dhruw, Omesh Thakur and Vivek Kurrey

ORGANIC FARMING 25. Biofertilizers: Types and their Applications ..................... 41

Savita B. Ahire and Mohitpasha S. Shaikh 26. Organic Agriculture: It’s Importance in Crop

Cultivation .................................................................... 42 L. Netajit Singh, Elangbam Bidyarani Devi, Elangbam Premabati Devi and Deepshikha

SUSTAINABLE AGRICULTURE 27. Bioplastic from Corn Starch ........................................... 44

N. Vairam 28. Neem –The Bitter Gem .................................................. 45

N. Vairam 29. Sustainable Agriculture: A Key Way to Manage

Land Degradation .......................................................... 47 Dinesh Kumar, Anil Kumar Mawalia and Vikas Vishnu

30. Remediation of Heavy Metals for Sustainable Crop Production ............................................................ 48 Subhaprada Dash and D. Sethi

31. Biochar: Tool to Mitigate Climate Change with Sustainable Crop Production ......................................... 49 P. N. Patle and S. A. Durgude

WATER MANAGEMENT 32. Salt Stress: Causes and Management ............................ 50

Dr. A. Suganya 33. Necessity of Water Harvesting in Hilly Regions

of Uttrakhand ................................................................ 52 D. C. Kala and Gangadhar Nanda

34. Introduction to Hydrological Model ................................ 53 Dileshwari, Mansingh Banjare

35. Drastic Model: Tools to Identified Groundwater Vulnerability .................................................................. 55 Dileshwari, Mansingh Banjare and Omesh Thakur

SOIL SCIENCE AND AGRICULTURAL CHEMISTRY 36. Management of Nitrogen Fertilizers in Soils .................... 56

A. G. Durgude and S. R. Kadam

37. Role of Potassium in Plants .......................................... 57 Dr. A. Suganya

38. Soil Respiration ............................................................ 57 Reshma B. Sale, S. R. Tatpurkar and Ruenna M. D’souza

39. Phosphorus: Its importance, Dynamics and Fate in Soils ........................................................................ 58 Dheeraj Panghaal and Chetan Kumar Jangir

40. Drought and Drought Management Strategies ................ 60 Dr. Archana Rajput

41. Salt Affected Soils and their Management ..................... 63 Chandra Sheker

42. Steenberg Effect in Relation to Application of Fertilizers ..................................................................... 64 S. A. Durgude and P. N. Patle

43. Soil Quality and Method for its Assessment ................... 65 Shabnam and Meenakshi Seth

AGRICULTURAL CHEMISTRY 44. Pesticides: Present Status, Regulatory Aspects

and Future Challenges .................................................. 66 Supriya Gupta, Pankaj Rautel and K. S. Bisht

45. Mycotoxins and Mycotoxicoses .................................... 68 Vinod Upadhyay and Akansha Singh

HI-TECH AGRICULTURE 46. Protected Agriculture in Smart India .............................. 70

M. S. Shah, Nidhi Verma and Akhilesh Jagre HORTICULTURE 47. Major Problems in Fruiting of Horticultural Fruit

Crops .......................................................................... 71 P. L. Deshmukh and V. A. Bodkhe

48. Rejuvenation Technology in Fruit Crops ........................ 73 P. L. Deshmukh and V. A. Bodkhe

49. Cultivation of Banana in Chhattisgarh ............................ 75 Chetna Banjare and Mridubhashini Patanwar

50. Methods of Vegetable Preservation ............................... 76 Gaikwad S. D. and Alekar A. N.

51. Different Warm Season Turf Grasses ............................ 77 Gawde N. V. and Bhondave S. S.

52. Marigold the Yellow Gold .............................................. 78 Latha S and Shivaprasad S G

53. Cashew: Needs the Intervention of Precision Farming ....................................................................... 79 Anindita Roy

54. Role of Integrated Nutrient Management in Vegetable Production ................................................... 80 Chetna Banjare and Mridubhashini Patanwar

55. Hydroponics in Rajasthan ............................................. 82 Devraj sisodiya, Dr. Mamta Meena, Jayendra Chouhan and Anupam kumar

56. Advance Production Techniques of Vegetable Cultivation ................................................................... 84 Sanjivani P. Gondane

GENETICS 57. Plant Morphological Traits and Tri-Trophic

Interactions .................................................................. 86 S. Routray

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AGROBIOS NEWSLETTER Publishing Date: 01 April, 2017

VOL. NO. XV, ISSUE NO. 11 5

PLANT BREEDING AND GENETICS 58. Linkage Disequilibrium Mapping as an

Advancement in Crop Breeding ...................................... 88 Parmeshwar Kumar Sahu and Satyapal Singh

59. Biofortification: A Tool to Combat Hidden Hunger of the Poor ........................................................ 89 Asit Prasad Dash and Soumitra Mohanty

60. Changes in Histone Dynamics at the Single-Cell Level Leads to Cell Differentiation and Development: Arabidopsis as an Example ...................... 91 Prem Chand Gyani, Nitin Sharma, Mallik M., and Jitendra Meena

61. Cisgenesis: A Technique for Crop Improvement ............. 92 Rameshraddy, Manjugouda I. Patil, Shivalingappa Bangi and Kumar K P

62. Managing Genetic Diversity to Control Wheat Rust ............................................................................. 93 Ranjana Patial and Neha Sharma

63. Distant Hybridization: Barriers of Inter-specific and Intergeneric Hybridization ........................................ 95 Ingle A. U. and K. G. Kandarkar

SEED SCIENCE AND TECHNOLOGY 64. Hybrid Seed Production Technology .............................. 96

Ashutosh S. Dhonde and Sunil D. Thorat 65. Workout of Seed Treating Equipment’s .......................... 98

Dr Pankaj P Jibhakate 66. Tetra Zolium Test .......................................................... 99

Chaudhary, V. P. 67. Demand Forecast for Seed Production and Seed

Marketing Structure ..................................................... 100 Himaj S. Deshmukh

68. Methods to Break the Dormancy .................................. 101 Arun Rathod and Subhalaxmi Roy

69. Technology for Seed Treatment ................................... 102 Aradhana Dhruw, Omesh Thakur and Vivek Kurrey

PLANT PATHOLOGY 70. Sheath Blight of Rice: Disease and Management .......... 104

Renu, Hradesh Kumar, Upasana Sahu and Khan Mohd. Sarim

71. Integrated Management of Major Diseases of Chickpea .................................................................... 105 Kalpana Gairola, Pooja Upadhayay and Akansha Singh

72. Allelopathy: A Promising Biological Control .................. 107 M. L. Meghwal

73. Cotton Leaf Curl Disease: A Potential Threat to Cotton Production ....................................................... 108 Anupam Maharshi, Priyanka Swami and Prachi Singh

PLANT PROTECTION 74. Spore Trapping: Principles and Methodology ................ 110

Dr. H. N. Kamble and A. G. Tekale 75. Host Resistance to Manage Mycotoxin

Contamination ............................................................ 112 Prachi Singh and Anupam Maharshi

ENTOMOLOGY 76. Distribution of Insects ................................................. 113

Hadiya G. D., Patel A. D. and Khambhu, C. V.

77. Co-Evolution: Ant: Acacia Mutualsim ...........................115 Divya Bharathi, T., Abdul Khadar B. and Shaila O.

78. Bed Bugs: Cimex lectularius L. ....................................116 Patel Aditi, Khambhu Chirag, Hadiya Girish and Chauhan Rinki

79. Odour Guided Host Findings in Anthropophilic Mosquitoes .................................................................117 K. L. Manjunatha, T. G. Avinash, Parasappa H Hulagabala

80. Non-Chemical Approaches for the Management of Stored Grain Insect Pests ........................................118 Ranvir Singh and Dharam Singh Meena

81. Reproductive Insect Ecology .......................................119 Rishikesh Mandloi

82. Effect of Climate Change on Insect Pests of Agricultural Importance ...............................................121 Koushik Sen, Arka Samanta, Sruba Saha and Pratyusa Bakshi

NEMATOLOGY 83. Nematodes Management in Protected

Cultivation ..................................................................123 Brajnandan Singh Chandrawat, Harshraj Kanwar and Dr. B. D. S. Nathawat

84. Root Knot Nematode ...................................................125 M. Kalaivani

EXTENSION EDUCATION 85. ICAR Infra-Structure for Agricultural

Development...............................................................126 Hiralal Jana

AGRICULTURAL ECONOMICS 86. Constraints of Marine Fisheries in Tamil Nadu ..............128

R. Thulasiram and P. Sivaraj 87. Inflation: Type, Factor, Effect and Remedies .................129

Y. Latika Devi, Jenny Kapngaihlian and T. Arivelarasan 88. Unemployment – Types, Consequences and its

Remedies ...................................................................130 Jenny Kapngaihlian, Y. Latika Devi and T. Arivelarasan

89. Farmer Producer Organisation .....................................131 Payal Jaiswal and Shyam Prakash Singh

AGRICULTURAL ENGINEERING 90. Contour Trenching and Contour Stone Wall for

the Water Conservation in Hilly Regions .......................133 Md. Majeed Pasha and Vinodkumar S.

91. Crop Cultivation and Management in Green House ........................................................................134 Md. Majeed Pasha and Vinodkumar, S.

FOOD SCIENCE 92. Parboiling: A Big Share of the Global Rice

Processing Industry ....................................................135 Butti Prabhakar, J. Srinivas and M. Vinaya kumari

93. High Pressure Processing in Food Industry ..................137 Manoharachari D.

94. Aseptic Packaging of Foods ........................................138 Pranjal S Deshmukh

95. Adolescent Nutrition ....................................................139 Kirti M. Tripathi

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DAIRY SCIENCE 96. Dairy and Dairy Food Packaging Trends ....................... 140

Dr. Chopade A. A. and Shri. Patil R. V. 97. DCAD and Milk Fever .................................................. 142

Khwairakpam Ratika and Rajkumar James singh

VETERINARY 98. Snake Poisoning in Animals ........................................143

K. Jayalakshmi and M. Sasikala

1. BIOTECHNOLOGY 14576

Vacuum Infiltration: Easy and Efficient Agro Bacterium Transformation Method

Anand Wagh1 and Pravin Herode2

1Research Scholar, Biotechnology Centre, Dr. Panjabroa Deshmukh Krishi Vidyapeeth, Akola, Maharashtra 444 104

2SRA, Sharad Pawar Agriculture Polytechnic College, Jalgaon Jamod, Maharashtra 443402

Plant transformation is at a threshold. The capacity to introduce and express diverse foreign genes in plants, first described for tobacco in 1984 has been extended to over 120 species in at least 35 families. Successes include most major economic crops, vegetables, ornamental, medicinal, fruit, tree, and pasture plants.

Attention is increasingly being directed to achieving the desired patterns of expression of introduced genes and to solving economic constraints on practical plant molecular improvement. There are excellent recent reviews of the development of plant transformation systems using Agrobacterium direct gene transfer and the potential for their practical application.

Agrobacteria are soil-borne, bacterial plant pathogens which cause tumorous growths or roots to develop on infected plants. The opine concept explains these growths by the presence of host (plant)-synthesized opines incited by the parasitic agent (bacteria). These opines create a chemical environment which favors the continued proliferation of the agent (bacteria). The opines supply the carbon and nitrogen needed by the bacteria for growth and incite conjugal transfer of its plasmid to neighbouring bacteria (genetic colonization).

Transformations based on the use of Agrobacterium tumefaciens are routine methods in laboratory. These methods have high transformation efficiency (about 30%). However, they are time consuming and laborious, and require sterile conditions and tissue culture systems for callus induction, somatic embryogenesis, and regeneration. Somatic mutations frequently occurring in the course of tissue culture often result in the difficulties while analyzing the phenotypes of transgenic plants in the subsequent generation. Therefore, transformation methods without the use of tissue culture and plant regeneration are highly desirable. The in planta transformation eliminated the tissue culture process and required only the soaked mature seeds. A. tumefaciens was directly used to transform the soaked mature seeds

pierced by a needle. Phenotype and molecular analyses were performed on T1 or subsequent generation transformants. This method made the transformation of plants much easier. Under a vacuum condition, Agrobacterium can infiltrate into the plant part to be transformed, and therefore the transformation efficiency is significantly improved.

The use of Agrobacterium- mediated transformation assisted by vacuum infiltration was first reported in Arabidopsis. Since then many improvements have been made. For example an efficient gene transfer system without tissue culture step for the transformation of kidney bean by combining sonication and vacuum infiltration techniques. Transgenic kidney bean with a group 3 lea (late embryogenesis abundant) protein gene from Brassica napus was produced through this approach. The transformation efficiency of this method can reach a value as high as 12%. In comparison, the transformation efficiency obtained by Agrobacterium-mediated transformation with the application of sonication technique alone is only about 2%. This method has also been successfully applied to the transformation of other crops such as Brassica napus, cabbage, and radish.

In this article I aim to introduce a simplified method for the transformation of rice by combining piercing technique and vacuum infiltration of the mature embryo with Agrobacterium-mediated transformation in rice. The proposed method can make the transformation of rice much easier and significantly shorten the subsequent analytical process of transgenic plants.

Method

Plant materials, Agrobacterium tumefaciens strains and binary vectors:

A. tumefaciens strain and binary vectors (for eg pCAMBIA) can be used in study. Subclone the gene of interest into the particular site of one vector which contains marker gene, the reporter gene and green fluorescent protein (GFP) gene.

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The other binary vector contains the antibiotic resistance gene and the b-glucuronidase (GUS) gene. The target gene and the report genes (GFP and GUS) all driven by the particular promoter and would express the fusion proteins in the transgenic plants. Introduce the constructs into strain by electroporation. Use the untransformed plants as controls.

Transformation Procedure

Agrobacterium tumefaciens strain harboring vectors culture on plates (particular medium) at specified period. Collect the densely grown bacteria. Use bacterial cell suspension as the Agrobacterium inoculum.

Sterilize the rice seeds as per the standardized procedure. After sterilization, rinse thoroughly and soak in sterile water at specified period. Nearly after 2 days of soaking, the embryo region of the seeds turns white. Then pierce embryo once by a needle (U0.5 mm; common hand sewing needle). The depth of piercing should be about 1 mm. Please note that before piercing, the needle must be dipped in the Agrobacterium inoculum. In order to inoculate Agrobacterium into the embryonic apical meristem and not to seriously damage the embryo, the needle should pierce the side of the plumule which lies beneath the husk where a shoot would later emerge.

Place the pierced seeds in a conical flask and soak in the Agrobacterium inoculum. Place the conical flask with the seeds into a bell jar. Draw out the air in the bell jar by a vacuum pump at a pressure of 80 kPa for 15 min. Then, release the vacuum for 2 min and pump again for 3 min as described by Jin et al. (2004).

Subsequently, transfer the inoculated seeds

without rinsing onto filter papers on wet vermiculite in plates and incubate in the dark at specified time. Normally the inoculated seeds begin to germinate after 9 days of incubation. Immerse the seedlings in a carbenicillin solution for 1 h to remove the remnant Agrobacterium.

After immersion, transfer the seedlings to Potting Mix soil and grown in a greenhouse for 15 days

Check the successful transformation with different assays according to particular interest of transformation like resistance assay of T0 transformants, DNA isolation and PCR analysis of T0 transformants, Southern blot analysis of T1 transformants, Inheritance analysis of T1 transformants, Luminescent image examination of T1 transformants, Histochemical assay of b-glucuronidase activity in T1 transformants.

The method is very easy and efficient, needs to be worked more for its potential use.


RNA Interference Based Gene Silencing in Crop Improvement Thombare Devidas1 and Shinde Vishwajeet2

Department of Plant Molecular Biology and Biotechnology Indira Gandhi Krishi Vishwavidyalaya (IGKV), Raipur. (C. G.)

INTRODUCTION: RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression, typically by causing the destruction of specific mRNA molecules. RNA interference is process of double stranded RNA (dsRNA) is incorporated into cells which causes the specific degradation of mRNA of the same sequence. It was found on the nematode Caenorhabditis elegans that the double stranded RNA (dsRNA) was more effective to produce interference than either strand individually. RNAi techniques have been working with mRNA degradation, gene silencing, gene expression regulation, resistance to virus infection, and regulation of chromatin structure and genome integrity. RNAi provided a great opportunity in the

basic biological research and development of RNAi tools in crop improvement.

Discovery of RNAi

The RNAi was discovered in Caenorhabditis elegans where the worm responded biologically due to the exogenous induction of dsRNA (Grishok, 2007). dsRNA was injected into C. elegans observing specific and effective gene silencing effect which was named at RNAi (Fire et al., 1998). Andrew Fire and Craig Mello won the Nobel Prize for medicine for their discoveries on gene silencing.

Components of RNAi

Dicer: RNAi mechanism involves dsRNA

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processing, mRNA degradation where the Dicer acts as an essential component in the process. Dicer is a ribonuclease in RNase III family enzyme that’s functions is the processing of dsRNA to short double-stranded RNA fragments called small interfering RNA (siRNA). Dicer contains helicase domain, dual RNase III motifs and a region homologous to the protein of RDE1 or QDE2 or ARGONAUTE family. Dicer works on the first step of RNAi pathway as a catalyst starting production of RNA- Induced Silencing Complex (RISC).

RNA induced Silencing Complex (RISC): RISC or RNA-induced silencing complex is a siRNA directed endonuclease contains proteins and siRNA. It targets and destroys mRNAs in the cell complementary to the siRNA strand. When RISC finds the mRNA complementary to siRNA, it activates RNAse enzyme resulting in cleavage of targeted RNA. About 20-23 bp siRNA are able to associate with RISC and guide the complex to the target mRNA and combined together and degrades them, resulting in decreased levels of protein translation and knockdown the gene function.

RNA Dependent RNA polymerase: RNA-Dependent RNA Polymerases (RdRPs) play role in the silencing effect in RNAi and Post Transcriptional Gene Silencing (PTGS) mechanism. Due to the activity of RdRps, RNAi is more powerful technique than the antisense approach of gene silencing in plants. This RdRPs activity was first observed in RNA viruses (Blumenthal and Carmichael, 1979).

Mechanism of Gene Silencing

The basic mechanism of RNAi is a multi-step process:

1. When the dsRNA entered in to the cell; it is targeted by the enzyme Dicer.

2. The Dicer cut the dsRNA in to smaller segments of 21-25 nucleotides.

3. The siRNA associate with RISC in the cell cytoplasm, interact with the catalytic RISC component which contains several proteins surrounding siRNAs.

4. siRNA duplex then loose its double strand and bind to the targeted mRNA, cleave it in the region covered by siRNA.

5. The siRNA fragments were first observed in plants undergoing post transcriptional gene.

Post Transcriptional Gene Silencing (PTGS)

In Post transcriptional gene silencing, target gene is destroyed through mRNA degradation. Incorporation of homologous dsRNA transgene or virus is the cause of silencing endogenous gene expression where silence gene transcription is synthesized but does not accumulate due to rapid degradation. PTGS is frequently referred to as co-suppression in plants and considered as the

hottest topic of molecular biology. Sense transgenes, antisense transgenes and sense/antisense transgenes or viruses may affect PTGS expression and classification. The destruction of the mRNA prevents translation to form a protein. It has been shown that PTGS same as TGS can occur in cis, simultaneously in cis and trans, or in trans position. The first reports of dsRNA mediating PTGS were made simultaneously in plants.

FIG. 1. RNAi mechanism. siRNAs associated with RISC. Active RISC binds as well as cleaves mRNA to stop protein synthesis (Rahman et al., 2008).

Application of RNA Interference for Crop Improvement

Modification of plant height via RNAi suppression of OsGA20ox2 gene in rice

Using RNAi to improve plant nutritional value

Technology reduces Gossypol in cotton seed

Using RNAi for Targeted Gene Silencing in Plants

RNAi Facilitates New Genetic Studies in Hybrids

Application of RNAi interference in plant systems Barley, Rice, Banana, Cotton

Increasing grain amylose content: Lathyrus sativus and Coffee

References Montgomery M. K., Xu S. and Fire A. (1998) RNA as

target of double-stranded RNA-mediated genetic interference in Caenorhabditis elegans. Proc. Natl Acad. Sci. 95:15502-15507.

Grishok A. (2007) The nuclear aspect of RNAi in C. elegans. J. RNAi Gene Silencing 3(1): 254-263.

Rahman M., Ali T. H., Riazuddin S. (2008) RNA interference: The story of gene silencing in plants and humans. Biotechnol. Adv. 26(3): 202-209.

Bluementhal T., Carmichael G. G. (1979) RNA replication: Function and structure of Qbeta-replicase. Ann. Rev. Biochem. 48: 525-548.

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Estimation of Reducing Sugars by Dinitrosalicylic Acid (DNS) Method Shinde Vishwajeet Sadashivrao and Thombare Devidas Tulshiram

Ph.D. scholar, Department of Plant Molecular Biology and Biotechnology, Indira Gandhi Krishi Vishwavidyalaya (IGKV), Raipur (C.G.)

INTRODUCTION: Carbohydrates are the most abundant class of organic compounds found in plants and animals and they also serve as a structural material (cellulose). Carbohydrates are a major source of metabolic energy, component of the energy transport compound ATP, recognition sites on cell surfaces. In order to measure the concentration of carbohydrates present in a solution, DNSA method can be used.

This method detects the presence of free carbonyl group (C=O), present in the so-called reducing sugars. This involves the oxidation of the aldehyde functional group present in, for example, glucose and the ketone functional group in fructose. Simultaneously, 3, 5-dinitrosalicylic acid (DNS) is reduced to 3-amino, 5-nitrosalicylic acid under alkaline conditions which is red brown in colour with absorbance maximum at 540 nm.

oxidation

reductionaldehyde group carboxyl group

3,5 dinitrosalicylic acid

3 amino,5 nitrosalicylic acid

Requirements

Equipment and glassware: Test tubes, pipette, spectrophotometer

Reagents: Dinitrosalicylic Acid Reagent Solution: prepare 100 ml of 1% (w/v) 3, 5-dinitrosalicylic acid in 0.7M NaOH solution by stirring on magnetic stirrer.

Procedure

Prepare 100ml glucose stock solution of 10mg/ml concentration.

Prepare glucose standards ranging from 0.0 to 1.0 mg ml-1 (total sample volume 3 ml)

Add 2 ml of DNS reagent to 3 ml of glucose standard solutions in a test tube.

Take 3 ml of glucose solution of unknown concentration and add 2ml DNS reagent to it.

Keep all the test tubes in boiling water bath for 5 to 10 minutes and let them cool.

Switch on the spectrophotometer and select the wavelength of 540 nm. First take the absorbance (OD) of Blank and make it zero.

Take the OD of all the tubes. Wash the cuvettes each time after taking OD.

Plot a graph of glucose concentration on x axes and absorbance at y axes. This is standard calibration curve.

Determine the value of glucose concentration in unknown samples using the standard calibration curve.

Important Instructions

Always use dry and clean glassware’s.

The unknown and standard samples should be treated identically for accurate results.

DNS reagent is corrosive, so handle it with care.


Cisgenesis and Intragenesis: A Marker Free Technique for Improving Crop

Shreya1, Kesha Ram2 and Geeta Vishnoi3 1Dept of Basic Science, College of Horticulture, SDAU, Jagudan, Mehsana, Gujarat-382710

2Department of Genetics and Plant Breeding, C P College of Agriculture, SDAU Sardarkrushinagar -385506

2Department of Genetics and Plant Breeding, SKRAU, Bikaner-600122

Transgenics could be an efficient and less time consuming means of improving our crops by manipulating the genetic constitution of plants resulting into the formation of GMOs (Genetically modified organism). However, GMOs are often associated with safety concerns, health issue and environmental risks due to the presence of foreign

DNA which may be a gene even from bacteria. The full potential of GM crops can be realized only with an increased acceptance by the general public. Moreover, the costly, hectic and lengthy procedures for obtaining approval of these crops and the threat for potential health risks and the spread of new gene into other unrelated crops are

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the major drawback in the path of implementing these techniques.

Due to the unacceptability and to ensure an eco-friendly crop improvement techniques two novel approaches cisgenesis and intragenesis has been developed as alternatives to transgenics (Holm et al, 2013). In both the techniques, a DNA fragment from the species itself or from a cross compatible species is inserted into the plant genome. In cisgenesis, the inserted gene is unchanged and contiguous and flanked by its own promoters and regulatory elements whereas, in intragenesis, an artificially synthesized novel combination of DNA fragments, but from the species itself or from a cross compatible species is used for the transformation process (Lusser et al, 2011). The same gene pool is exploited by intragenesis and cisgenesis that are available for traditional breeding (Holme et al, 2013). The European Food Safety Authority (EFSA) has determined the hazards of cisgenic/ intragenic crops compared to transgenesis or traditional breeding (EFSA Panel on Genetically Modified Organisms, 2012). That report reveals that hazards associated with cisgenesis, intragenesis, transgenesis and conventional breeding originate from the source of the gene, the phenotype and possible genome rearrangements as a result of the modification. Moreover, it was proposed that cisgenesis could imply similar hazards to traditional breeding, while transgenesis and intragenesis are less predictable.

“Cisgenic plant” was first time defined by Schouten in the year 2006 as “a crop plant that has been genetically modified with one or more genes (containing introns and flanking regions such as native promoter and terminator regions in a sense orientation) isolated from a crossable donor plant”. From this it is clear that all the necessary elements of a natural gene is present is a cisgenic plant i.e., a perfect copy. The cisgene of a cisgenic plant is derived from the same plant species or a sexually compatible species as used for conventional plant breeding. In conventional or traditional breeding the improved crop contain the undesirable genetic element along with the gene of interest which reduces the efficiency of breeding. However this linkage drag in not found in cisgenic plant. For example cisgenic apple having resistance against apple scab and cisgenic barley having improved phytase activity have been developed (Telem et al, 2013).

Whereas intragenic crops refers to one which contain the new gene which is originating from the same species or a crossable species similar to the cisgenesis but in contrast to the cisgenes, intragenes are hybrid genes, which can have genetic elements from different genes and loci (Rommens et al., 2004). Due to the presence of different genetic elements like promoters, enhancers, terminators etc of different gene loci, expression of a certain gene can be modified.

Hence, Intragenesis allows the creation of novel expression patterns, the construction of new genetic combinations, introducing variability for gene expression, and consequently new GMOs with innovative properties. Cisgenesis can be considered much closer to conventional breeding based on the use of native genes in comparison with the use of hybrid genes in intragenesis. Another key difference between cisgenesis and intragenesis, is regarding the T-DNA borders or other sequences finally transferred to the plant as a consequence of the Agrobacterium-mediated transformation process, a topic which is not exempt from a certain degree of controversy (Holme et al., 2013). Gene silencing by using antisense or RNAi (RNA interference) can also be accompanied through Intragenesis (Lusser et al, 2011). The level and pattern of expression of newly created plants by Intragenesis can never be achieved through conventional breeding because in intragensis genes are present differently from the natural situation.

Crops like potato, apple, strawberry, and grapevine, were some of the crops in which cis/intragenic approaches for improvements were attempted for the first time (Holm et al, 2013). Recently, cisgenic crops have been developed in potato and apple to develop polygenic durable resistance against Phytophthora infestans and apple scab (Venturia inaequalis) respectively. Moreover, the MdMYB10 transcription factor from apple that upregulates the anthocyanin pathway, leading to red-fleshed apples have also been introduced (Schoute et al, 2011). Different growth types are produced due to overexpression of growth-related genes in popular using cisgenic approach (Han et al, 2011).

Through silencing of polyphenol oxidase gene (Ppo) to reduce black spot bruise and through silencing of three different genes to limit acrylamide formation and also reduced cold-induced sweetening, good processing qualities potato development is a remarkable example of this new approach in USA.

Intragenic alfalfa have been developed to improved forage quality with reduced levels of lignin through gene called caffeic acid o-methyltransferage. Intragenesis is currently being used to increase resistance in strawberry against grey mould by overexpressing the polygalacturonase inhibiting protein thereby, reducing the effect of fungal polygalacturonase and to produce non- browning apples by developing RNAi silencing constructs against the apple polyphenol oxidase gene (www.okanaganbiotechnology.com).

Cisgenesis vs Intragenesis

Cisgenesis Intragenesis

Specific alleles/genes present in the breeders’ gene pool are introduced, without

Genes can be designed using genetic elements from other plants with the same sexually

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Cisgenesis Intragenesis

any change to the DNA sequence, into new varieties.

compatibility gene pool.

Cisgenesis can accelerate the breeding of species with long reproduction cycles since it does not contain the linkage drag.

Thus, the coding regions of a gene can be combined with promoters and terminators from different genes (from the same sexually compatibility gene pool).

Conclusion: Cisgenesis/intragenesis has great potential to speed up the breeding process in plants particularly in increasing the quality parameters of different crops and in development of disease resistance and thereby can enhance the environmental and economic prospects of agriculture. Moreover the products obtained from cisgenesis/intragenesis are similar to the plants derived by conventional breeding or mutagenesis hence these approaches have more consumer acceptance than the transgenesis. EFSA Panel on GMOs also stated that similar hazards can be associated with cisgenic and conventionally bred plants. However, future developments regarding the generation and commercialization of intragenic and cisgenic crops will depend on application of less stringent regulation to these crops worldwide.

References Han K.M., Dharmawardhana P., Arias R.S., Ma C.,

Busov V. and Strauss S.H. 2011. Gibberellin-associated cisgenes modify growth, stature and wood properties in Populus, Plant Biotechnol. J. 9:162- 178.

Holme I.B., Wendt T. and Holm P.B. 2013. Intragenesis and cisgenesis as alternatives to transgenic crop development, Pl. Biotech. J. 11: 395–407.

Lusser M., Parisi C., Plan D. and Rodriguez-Cerezo E.2011. New plant breeding techniques: State-of-the-art and prospects for commercial development, JRC Scientific and Technical Reports. Luxembourg, European Union.1-220.

Organism E.P.O.G.M. 2012. Scientific opinion addressing the safety assessment of plants developed through cisgenesis and intragenesis.

Rommens, C.M., Humara, J. M., Ye J., Yan H., Richale C., Zhang L., Perry, R and Swords, K. 2004. Crop improvement through modification of the plant's own genome. Plant Physiol. 135 (1): 421-431.

Schouten, H.J., Krens, F.A and Jacobsen, E. 2006a. Cisgenic plants are similar to traditionally bred plants: international regulations for genetically modified organisms should be altered to exempt cisgenesis. EMBO Rep. 7: 750-753.

Schoute H.J. 2011. Cisgenesis for crop improvement. World congress on biotechnology. 21-23 March HICC Hyderabad, India.

Telem, R.S., Wani, S.H., Singh, N.B., Nandini, R., Sadhukhan, R., Bhattacharya, S. and Mandal, N. 2013. Cisgenics – A sustainable approach for crop improvement. Current Genomics. 14:468-476.

5. MOLECULAR BIOLOGY 14386

VIGS (Virus Induced Gene Silencing): A Tool to Study Plant Gene Function

Haidar Abbas Masi and Pravin Prajapat

Ph.D. Scholar, Department of Plant Molecular Biology and Biotechnology, Navsari Agricultural University, Navsari- 396 450, Gujarat

INTRODUCTION: Global population has reached around 7 billion and is estimated to be more than 9 billion, till 2025 (FAO, 2014). To meet the global demand for food, crops production need to be increase. Genome sequencing and transcriptome analysis in model and crop plants has made possible to identify vast number of genes potentially associated with economically important traits. But, the exact function of most genes is un-cleared. Also, previous techniques used for gene analysis required mutant collections and protocols for stable genetic transformation, which are costly and extremely time consuming. However, VIGS is ultimate technique of reverse genetics to assign functions to the genes. VIGS is comparatively fast and reliable method to achieve down regulation of target gene expression.

Plant biologists adapted homology-based defense mechanisms triggered by incoming viruses to target individual genes for silencing in a

process called virus-induced gene silencing (VIGS). Antisense- and sense-mediated inhibition of gene expression was commonly used to downregulate gene expression in plants and in C. elegans, but its efficiency varied in different transformants. A breakthrough that started the use of RNAi as a general silencing tool occurred when it was found that only small amounts (a few molecules) of dsRNA injected into C. elegans were needed for widespread silencing similar to PTGS in plants Many different RNA and DNA viruses have been modified to serve as vectors for gene expression. Some viruses, such as tobacco mosaic virus (TMV), potato virus X (PVX), and tobacco rattle virus (TRV), can be used for both protein expression and gene silencing.

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Fig.1 VIGS mechanism

Host for VIGS

N. benthamiana has been extensively used for silencing studies because it is a suitable host for a wide range of viruses. It can be readily transformed by Agrobacterium cocultivation of leaf discs, self-pollinates, flowers rapidly, and is of smaller stature than tobacco. N. benthamiana has advantages over Arabidopsis that include limited symptoms and abundant leaf material for biochemical analysis.

The power of VIGS is its rapid initiation of silencing in intact wild-type or transgenic plants. The ability to reliably silence 1–2 genes can provide material for biochemical analysis, metabolic profiling, and transcript profiling, if suitable controls are included. Networks of genetic and protein interactions change when mRNA levels for individual genes are altered and information can be obtained for both medium and high levels of silencing, as demonstrated in Arabidopsis. Keep in mind that silencing is a method for modulating gene expression, not eliminating it.

VIGS Inoculation Technique

1. Direct infection: Modified viral particles directly used for infection by rubbing on the plant surface or injecting. As the plant grows, the virus spreads from the site of inoculation into the developing regions of the plant and triggers PTGS.

2. Agrobacterium mediated inoculation: To facilitate faster virus inoculation, RNA virus genomes have been placed under the control of the CaMV 35S promoter into binary vectors for Agrobacterium-mediated expression in plant cells.

Stages of VIGS

A key point from our analysis is the separation of initiation and maintenance stages of VIGS. Initiation of VIGS is absolutely dependent on the virus. The target genes were not silenced unless the plants were infected with the corresponding viruses, and if the virus levels declined, VIGS was not initiated in the newly developing tissue at the growing point of the plant However, once initiated, VIGS of GFP persisted even in the absence of the inducing virus, indicating that the virus is not required for maintenance of VIGS.

Initiation of VIGS could be determined by an interaction of the viral RNA with the corresponding nuclear gene or at the RNA level with the mRNA. Alternatively, VIGS could be initiated by the virus, independently of the nuclear gene.

Analysis

1. Visual analysis: GSA, PDS, ChlI, ChlH, and PAI genes have visual phenotypes following silencing. GFP (Green Fluorescent Protein) and PDS (Phytoene Desaturase) are widely used for VIGS analysis for gene silencing. GFP gives fluorescence after illumination and PDS silencing causes albino or patches on green leaves.

2. Molecular analysis: This could be done by agarose gel electrophoresis or comparative expression analysis br RT-PCR.

Applications

VIGS has been used to silence a wide variety of genes in plants. There have been elegant studies combining VIGS with biochemical and genetic methods to determine gene function, and they are producing a coherent picture of gene function. It would be possible to silence a gene by VIGS and thereby determine the role of the gene product much more quickly than by using antisense or sense suppression. It also will be possible to use cDNA libraries in a forward genetics approach based on VIGS.

Future Aspects: Libraries of VIGS vectors with sequenced inserts would be useful resources for functional genomics studies. Unlike transgenes, which are subject to epigenetic modifications, VIGS vectors can be used for reliable silencing and can be used in different genetic backgrounds and for various screens. This versatility is especially useful because many phenotypes are not evident until proper environmental conditions are reached. Environment by genotype variations (for example, in stress tolerance assays) will likely require large numbers of plants and it is difficult to predict what genes will be useful for further testing before these kinds of studies are performed. Because seed storage and archiving can be labor-intensive processes, developing community resources for RNA silencing–based vectors would be useful. Viruses with broad host range, such as BSMV and TRV, will be useful for extending functional data from model systems to crop plants. Gemini viruses are also attractive for gene silencing vectors because their genome structure is conserved and they infect a wide range of crop plants including soybean, cotton, and vegetable crops.

Reference Lange, M., Yellina, A.L., Orashakova, S. and Becker,

A. (2013). Virus-induced gene silencing (VIGS) in plants: an overview of target species and the virus-derived vector systems. Virus-Induced Gene Silencing: Methods and Protocols, pp.1-14.

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Ruiz, M.T., Voinnet, O. and Baulcombe, D.C., 1998. Initiation and maintenance of virus-induced gene

silencing. The Plant Cell, 10(6): 937-946.

6. MOLECULAR BIOLOGY 14803

Crispr/Cas9: A Genome Editing Technology 1Rameshraddy*, 1Shivalingappa Bangi, 1Manjugouda I. Patil, and 2Kumar K P

1Department of Crop Physiology, UAS, GKVK, Bengaluru-65, 2Department of Entomology, UAS, GKVK, Bengaluru-65

*Corresponding Author eMail: [email protected]

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is Type II bacterial immune system that has been modified for genome engineering. Prior to CRISPR/Cas9 like zinc finger nucleases (ZFNs) or transcription-activator-like effector nucleases (TALENs) relied upon the use of customizable DNA-binding protein nucleases that required scientists to design and generate a new nuclease-pair for every genomic target. Largely due to simplicity and its adaptability, CRISPR has rapidly become one of the most popular approaches for the genome engineering.

CRISPR has two components: a guide RNA (gRNA) and a non-specific CRISPR-associated endonuclease (Cas9). The gRNA is short synthetic RNA composed of a scaffold sequence that is necessary for Cas9-binding and a user-defined ∼20 nucleotide “spacer” or targeting the sequence which defines the genomic target that leads to be modified. Thus, one can change the genomic target of Cas9 by simply changing the targeting sequence which is present in the gRNA. CRISPR was originally active to knock-out target genes in various cell types and also in organisms, but modifications to the Cas9 enzyme have extended the application of CRISPR to selectively activate or repress target genes, purify specific regions of the DNA, and also see the DNA image in live cells using fluorescence microscopy. Furthermore, the comfort of generating gRNAs makes CRISPR one of the most accessible genome editing technologies and has been recently utilized for genome-wide screens.

Gene Knock-out Using CRISPR/Cas9

CRISPR/Cas9 is used to generate knock-out cells or animals by co-expressing a gRNA specific to the gene to be targeted and the endonuclease Cas9. The genomic target can be any ∼20 nucleotide DNA sequence, provided it meets two conditions:

The sequence is unique compared to the rest of the genome.

The target is present immediately upstream of a protospecer Adjacent Motif (PAM).

The PAM sequence is absolutely necessary for the target binding and the exact sequence is mainly dependent upon the species of Cas9. In Streptococcus pyogenes Cas9 is most widely used

in genome engineering. Once expressed, the Cas9 protein and the gRNA form a riboprotein complex through interactions between gRNA scaffold domain and surface-exposed positively-charged grooves on Cas9. Cas9 undergoes a conformational change upon the binding of gRNA that shifts the molecule to from an inactive, non-DNA binding conformation, into an active DNA-binding conformation. The spacer sequence of the gRNA that remains free to interact with target DNA. The Cas9-gRNA complex will bind any genomic sequence with a PAM, but the extent to which the gRNA spacer matches the target DNA determines whether Cas9 will cut. Once the Cas9-gRNA complex binds to a putative DNA target, a sequence at the 3′ end of gRNA targeting sequence begins to anneal to the target DNA. If the seed and target DNA sequences matches, the gRNA will continue to anneal to the target DNA in a 3′ to 5′ direction.

Cas9 will only cleave the target if sufficient homology exists between the gRNA spacer and the target sequences. The zipper-like annealing mechanics may help to explain why mismatches between the target sequences in 3′ seed sequence completely abolish target cleavage, whereas mismatches toward the 5′ end are permissive for the target cleavage. Cas9 nuclease has a two functional endonuclease domains: RuvC and HNH. Cas9 undergoes conformational change upon target binding that positions the nuclease domains to cleave opposite strands of the target DNA. resultant of Cas9-mediated DNA cleavage is a double strand break (DSB) within the target DNA (∼3-4 nucleotides upstream of the PAM sequence).

The resulting DSB is then repaired by one of two general repair pathways:

1. Non-Homologous End Joining (NHEJ) pathway

2. Homology Directed Repair (HDR) pathway

The NHEJ repair pathway is most active repair mechanism, capable of rapidly repairing DSBs, but frequently results in small nucleotide insertions or deletions at DSB site. The randomness of NHEJ-mediated DSB repair has important practical implications, because the population of cells expressing Cas9 and a gRNA will result in a different array of mutations. In

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most of the cases, NHEJ gives rise to small in the target DNA result in in-frame amino acid deletions, insertions, or frameshift mutations leads to premature stop codons within the open reading frame (ORF) of the targeted gene. Ideally, the end

result is a loss-of-function mutation within the targeted gene; however, the strength of the knock-out phenotype for a given mutant cell is ultimately determined by the amount of residual gene function.

7. MICROBIOLOGY 14617

Edible Plant Vaccines: An Advanced Approach of Oral Immunization

Bharat Taindu Jain and Hirdayesh Anuragi

Ph.D. Scholar, Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar

INTRODUCTION: According to WHO, various diseases cause 80% of illnesses worldwide resulting in more than 20 million deaths annually. Vaccines are used most widely in the world. They have reduced mortality rate caused by various infectious organisms. Their use has been considered one of the safe and effective measure and to control various infectious diseases. But a mind disturbing reality, which has been generally unrecognized, is the ever growing number of individuals suffering from adverse reactions to vaccines. Edible vaccine can be one of the alternatives of the traditional vaccines as they can overcome all the problems associated with traditional vaccines. For obtaining edible vaccine, selected gene of interest is administered to the plant. Transgenic plant is then induced to

manufacture the encoded proteins. Edible vaccines are targeted to provide mucosal as well as systemic immunity. Plants like tomato, banana and cucumbers are generally the plants of choice.

What is Edible Vaccine?

These types of vaccines are antigenic proteins that are genetically engineered into a consumable crop. The strategy is that the plant food product haves the protein which is obtained from some disease causing pathogen. The genes encoding antigens of bacterial and viral pathogens can be expressed in plants in a form in which they retain native immunogenic properties. When such plant food products are orally vaccinated, they stimulate the mucosal and systemic immunity in the body against pathogen.

FIG. 1: How to produce an edible vaccine.

How to Produce an Edible Vaccine

The gene encoding the orally active antigenic protein is isolated from the pathogen, and a suitable construct for constitutive or tissue -specific expression of the gene is prepared. The gene construct is introduced and stably integrated into genome of selected edible plant species, and is expressed to produce the antigen. The

appropriate plant parts having the antigen may be fed raw to animals or humans to bring about immunization. For animals, crops used as feed, e.g., alfalfa, and other forage/ fodder crops are suitable for the expression of such antigens, while for humans fruits like banana, which are consumed raw, have to be used. The edible vaccines are produced from transgenic plants in

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witch orally active antigen of the target pathogen is expressed and accumulated, and witch is fed to animals/ humans for immunization against the pathogen.

Examples of Edible Vaccines

Target Pathogens Expressed in

Mode of Administration

Enterotoxigenic E coli (humans)

Potato, tobacco

Immunogenic and protective when administered orally

Vibrio cholera (humans)

Potato Immunogenic and protective when administered orally

Hepatitis B virus (humans)

Tobacco Extracted proteins is Immunogenic when administered by injection

Hepatitis B virus (humans)

Potato Immunogenic and protective when administered orally

Norwalk virus (humans)

Potato Virus like particles form and Immunogenic when administered orally

Rabies virus (humans)

Tomato Intact glycoproteins

Foot and mouth disease (agricultural domestic animals)

Arabidopsis Immunogenic and protective when administered orally

Foot and mouth disease (agricultural domestic animals)

Alfalfa Immunogenic and protective when administered by injection or orally

Transmissible gastroenteritis corona virus (pigs)

Maize Protective when administered orally

AIDS/HIV (human) Tomato Immunogenic and protective when administered orally

Diarrhea Tomato Immunogenic and protective when administered orally

Advantages of Edible Vaccine

Efficient way to deliver (oral) for immunization

Elicits mucosal immunity which is not observed in traditional vaccines

Cost effective in storage, preparation, production and transportation

Easily available as they are produced from plants

Easily acceptable as they do not require administration by injection unlike traditional vaccines

Could be the source for new vaccines combining numerous antigens

More safe than traditional vaccines as there is no attenuated pathogens used

Easy to produce in large quantity through breeding

Are stable to heat in nature

Acceptable for poor developing country

No fear of contamination

FIG. 2: Edible vaccines (transgenic potato against diarrhea, banana and transgenic tomato against diarrhea)

Limitations of Edible Vaccine

Chances of development of immune-tolerance to the vaccine protein

Non consistency of dosage

Stability of vaccine differs from plant to plant

Cooking of some foods denatures or weakens its protein

Perishability of edible vaccines is a major limitation.

Conclusion: Edible vaccine might be solution to get rid of various ailments as it has more advantages compared to traditional vaccine. It would overcome the problems associated with traditional vaccine like cost, production, distribution and delivery and could be incorporated into the immunization plans. It would be more beneficial and profitable to populations of developing world. But still there is lack of production and investment in this new technology but it will be likely conquered to make plant derived vaccine more efficient and dependable.

Future Thrust: Edible vaccines hold great potential especially in developing countries as it can overcome difficulties of production, storage and distribution associated with traditional vaccines. Countries with limited health care resources have scope of immunization against serious diseases using plant derived vaccines. Challenges like developing different strategies for higher accumulation and stability of proteins in the food have to be tackle through advanced molecular approaches. There are some safety concerns which need to be overcome in near future.

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8. MICROBIOLOGY 14879

Single Cell Protein: Production and Process Jasmin M. Nadaf

Ph.D. Scholar, Dept. of Plant Pathology and Agril. Microbiology, MPKV, Rahuri, Maharashtra.

A variety of microorganisms and substrate are used to produce single cell proteins. Yeast is suitable for single cell protein production because of its superior nutritional quality. The supplementation cereals with single cell protein, especially yeast, make them as good as animal proteins (Huang and Kinsella, 1986).The necessary factor considered for use of SCP is the demonstration of the absence of toxic and carcinogenic compounds originated from the substrates, biosynthesized by the microorganisms or formed during processing. It has been calculated that 100 lbs of yeast will produce 250 tons of proteins in 24 h. Algae grown in ponds can produce 20 tons(dry weight) of protein, per acre, per year. Yeasts have advantages such as their larger size (easier to harvest), lower nucleic acid content, high lysine content and ability to grow at acidic pH. Filamentous fungi have advantages in ease of harvesting, but have their limitations in lower growth rates, lower protein content and acceptability. Algae have disadvantages of having cellulosic cell walls which are not digested by human beings.

Microorganism and substrates used for single cell protein production

Microorganism Substrate

Bacteria Aeromonas hydrophylla Lactose

Acromobacter delvacvate

n-Alkanes

Acinetobacter calcoacenticus

Ethanol

Bacillus magaterium Non-protein nitrogenous compound

Bacillus subtilis,Cellulomonas sp.

Cellulose,Hemicellulose

Lactobacillus sp. Glucose,Amylose

Fungi Aspergillus fumigatus Maltose,Glucose

Aspergillus niger,A.oryzae

Cellulose,Hemicellulose

Rhizopus chinensis Glucose,Maltose

Trichoderma viridae Cellulose,Pentose

Yeast Amoco torula Ethanol

Candida tropicalis, Candida utilis

Maltose,Glucose

Candida novellas n-alkanes

Saccharomyces cereviciae

Lactose,pentose

Microorganism Substrate

Algae Chlorella pyrenoidosa, spirulina sp.,

CO2 through photosynthesis

Chlorella sorokiana

Production

The production of single cell protein takes place in a fermentation process is done by selected strains of microorganisms which are multiplied on suitable raw material in technical cultivation process directed to the growth of the culture and the cell mass followed by separation processes.

SCP Derived from High Energy Sources: Material with high commercial value as energy sources or derivatives like gas oil, methane, methanol and n-alkanes are of interest in SCP production. The microbes involved are mostly bacteria and yeast and several processes are now in operation. British Petroleum uses two yeasts, Candida lipolytica and C. tropicalis and C12-C20 alkanes as substrate which is of the wax fraction of gas oils for treating. Methanol as a carbon source for SCP has many inherent advantages over n-paraffins, methane gas and even carbohydrates composition is independent of seasonal fluctuations. Methanol represents approximately 50% of the costs of the products. In the USA the cost of SCP derived from methanol is two-to five-folds the cost of fishmeal. Ethanol is a particular suitable source if the SCP is intended for human consumption. Many genera of yeast and molds utilize aliphatic hydrocarbons (alkanes and alkenes) for growth and for SCP production. These microorganisms secrete emulsifying substances during fermentation which increase the solubility of alkanes and alkenes.

SCP from Wastes: The amount of agricultural and some industrial wastes used for SCP production can be locally very high and may contribute to a significant level of pollution in watercourses. Cellulose from agriculture and forestry sources constitutes the most abundant renewable resource in the planet as potential substrate for SCP production. Cellulose has emerged as an attractive substrate for SCP production but in nature it is usually found with lignin, hemicellulose, starch, etc, in complex form. A number of efficient cellulose producers have been reported but Trichoderma viride continued to be well known high cellulose producing organism. Chaetomium cellulolyticum is another cellulolytic fungus which grows faster and forms 80% more biomass-protein than Trichoderma.

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This means that C. cellulolyticum is suitable for SCP production while T. viride is a hyper producer of extracellular cellulases. A cheaper, more amenable SCP substrate of carbohydrate origin is starch. This very abundant carbohydrate may be obtained from rice, maize and cereals. In Tropical countries, cassava has been proposed as good source of starch for SCP processes. The symba process developed in Sweden utilized starchy wastes combining two yeasts in sequential mixed culture: the amylase producing Endomycopsis fibuligira and the fast growing candida utilis. Coffee-pressing wastes contain soluble carbohydrates and have a high chemical oxygen demand (COD) and soluble solid contents. In Guatemala, Trichoderma sp. Is used to produce SCP on this substrate. Cellulomonas grows on bagasse and Thermoactinomyces on fermented livestock wastes (Humphrey, 1975).

Fermentation Process

The fermentation process requires a pure culture of the chosen organism that is in the correct physiological state, sterilization of the growth medium which is used for the organism, a production fermenter which is the equipment used for drawing the culture medium in the steady state, cell sepration, collection of cell free supernatant, product purification and effluent treatment. Fed-batch fermentations are better

suited for the purpose of biomass production, since they involve the control of the carbon source supply through feeding rates. Fed-batch culture is still in use for baker’s yeast production using well established and proven models (Steinkraus, 1986).The most commonly used principle has been the chemostat: a perfectly mixed suspension of biomass into which medium is fed at a constant rate and the culture is harvested at the same rate so that the culture volume remains constant. Production periods as long as six weeks have been implemented in many fungal and yeast (Forage and Righelato, 1979). Air-lift has enjoyed the greatest success as the configuration of choice for continuous SCP production. These is presently used in the production of myco-protein which is the basis for QuornTM products.

Application

1. Single cell proteins have application in animal nutrition as: Fattening calves, poultry, pigs and fish breeding.

2. In the foodstuffs area as: aroma carriers, vitamin carrier, emulsifying aids and to improve the nutritive value of baked products, in soups, in ready-to-serve meals, and in diet recipes.

3. In the technical field as: paper processing, leather processing and as foam stabilizers.

9. AGRICULTURAL MICROBIOLOGY 13754

Microbial Retting of Jute K. Damodara chari

1Ph.D. Scholar, College of Agriculture, Professor Jayashankar Telangana State Agriculture University, Hyderabad-500030

Retting: The process of separation and extraction of fibres from non-fibrous tissues and woody part of the stem through dissolution and decomposition of pectins, gums and other mucilaginous substance is called retting. The microorganisms, mostly bacteria from retting water enter the plant tissues through the stomata, epidermis and cambium or the cut end, when immersed in retting tank, and through their enzymatic action loosens the fibre strands from the woody core. Absorption of water by jute plants and liberation of soluble constituents like sugar, glucosides and nitrogenous compounds from jute plants favouring initial microbial growth. Further, these microbes utilize free sugars, pectins, hemicellulose and proteins of the plants as essential nutrients for their development and multiplication under the favourable condition. Secretion of specific enzymes like pectinase, hemicellulase or xylanase by microbes and degradation of the respective complex organic materials. The decomposition of free sugar present in jute and mesta plants takes place at

early stage of retting, followed by pectins during middle stage, and hemicellulose, sugars and nitrogenous compounds (mainly proteins) at later stage of retting.

Collection of Retting Water Sample: Retting water samples were collected from high and medium productivity as well as Good-quality jute fibre producing districts of West Bengal. Retting liquor was collected between the jute bundles in the ‘jak’, where the growth of microorganisms are likely to be maximal.

Isolation of Pectinolytic Microorganisms: Isolation of pectinolytic microbes Pectinolytic bacteria were isolated by serial dilution and plating on Yeast extract-pectin agar and grown for 48 hrs at 340C. Colonies were then selected and replica plated. One of the replica plate was flooded with 2% cetrimide and washed with 1M NaOH. Colonies giving detectable halo zones and having a potency index (halo zone diameter/colony dia.) greater than 3mm were selected for enzymatic study.

Estimation of Pectinase activity Pectin lyase

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activity was estimated by reducing sugar estimation (Dinitro Salicylic acid reagent method) method with D-galacturonic acid as calibration standard at 535nm using three different substrates namely polygalacturonic acid sodium salt, citrus pectin and apple pectin. Estimation of xylanase activity. The screened isolates having very high pectinolytic activity were further tested for their xylanase activity. For degradation of xylan, the screened isolates producing clear halo zones on xylan agar were selected. Assay of xylanolytic activity was done by reducing sugar estimation method with 3,5- Dinitrosalicyclic acid using xylan as substrate and D-xylose as calibration standard.

Estimation of Cellulase Activity: These isolates were further screened for cellulolytic activity. Both qualitative (halo zone formation after flooding the colonies on CMC agar plate with congo red) and quantitative estimation by reducing sugar estimation method with 3,5-dinitro salicylic acid, using D-glucose as calibration standard, confirmed the absence of cellulolytic enzymes.

Screening for Antagonism: These promising isolates were further screened for antagonism by using standard method. The isolates screened out for making efficient retting consortium produce cellulose free- pectinase, xylanase and found compatible with each other.

Screening for Synergism: Finally the isolates were applied in all probable combination and tested for pectin degrading capability. Out of all possible combinations, a combination of three isolates was found to be very effective for jute retting purpose. Identification and Molecular Characterization done by 16S rDNA sequencing (ribotyping) base pair fragment and BLAST analysis.

Microbial retting consortium can be used for efficient retting either for ribbon retting or whole plant retting during water scarcity situation

utilizing minimum amount of ground water. Mechano-microbial retting of jute involves two distinct operations viz. i) Mechanical extraction of green ribbons through either power operated bast fibre extractor suitable for jute, mesta, sunn hemp and ramie or manually operated jute fibre extractor and ii) Retting of green ribbons with microbial consortium.

In situ Jute Retting with Microbial Consortium: A circular micro pond of 6.5 m floor diameter and 7.5 m top diameter and 1 m deep having 1 m wide earthen embankment lined with polyethylene sheet (800 to 1000 gauge, 30 ft x 27 ft) is sufficient to ret jute/ mesta harvested from 1333.3 M2 (one bigha) land. The sharp bases of the jute plants have to blunted by ramming the bundles on hard surface to avoid damage to the polyethylene sheet. A single layer of straw bundles arranged radially at the bottom of the pond over polyethylene/tarpulin sheet to avoid damage to the polyethylene sheet. Harvested jute bundles are arranged radially up to three layers keeping base of the plants towards periphery of the pond. Microbial consortium with a cfu (108 to 1010) was then applied to the jute bundles in the pond. Under ground water was then added to the retting tank and the jute bundles are then covered with straw/aquatic weeds. For proper immersion of the jute bundles in the water cement bags filled with sand, brick or soil can be put above the jute bundles. After retting, the fibres have to be washed in the retting pond itself after removal of 50 % retted water and addition of fresh water in the pond. The fibres are then sun dried on the embankment of retting pond.

Reference B. Majumdar, Microbial Retting of Raw Jute. Central

Research Institute for Jute & Allied Fibres, Barrackpore, Kolkata-700120, India.


A Review on Plant Growth Promoting Rhizobacteria Prajakta V. Sarkate1, Nilam B. Kondvilkar2 and MVVI Annapurna3

1,2,3Ph.D. Scholar, 1Dept. of Plant Pathology and Agril. Microbiology and 2,3Dept. of soil Science and Agril. Chemistry, MPKV, Rahuri, Maharashtra.

INTRODUCTION: Plant growth in agricultural soils is influenced by many abiotic and biotic factors. There is a thin layer of soil immediately surrounding plant roots that is an extremely important and active area for root activity and metabolism which is known as rhizosphere. The original concept of rhizosphere has now been extended to include the soil surrounding a root in which physical, chemical and biological properties have been changed by root growth and activity. A large number of microorganisms such as bacteria, fungi, protozoa and algae coexist in the

rhizosphere. Bacteria are the most abundant among them. Plants select those bacteria contributing most to their fitness by releasing organic compounds through exudates creating a very selective environment where diversity is low. Microorganisms that colonize the rhizosphere can be classified according to their effects on plants and the way they interact with roots, some being pathogens whereas other trigger beneficial effects. Rhizobacteria inhabit plant roots and exert a positive effect ranging from direct influence mechanisms to an indirect effect. So, the bacteria

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inhabiting the rhizosphere and beneficial to plants are termed PGPR. Various species of bacteria like Pseudomonas, Azospirillum, Azotobacter, Klebsiella, Enterobacter, Alcaligenes, Arthrobacter, Burkholderia, Bacillus and Serratia have been reported to enhance the plant growth. PGPR also play role as biofertilizer, biostimulant, bioprotectant. Siderophores produced by some PGPR scavenge heavy metal micronutrients in the rhizosphere (e.g. iron) starving pathogenic organisms of proper nutrition to mount an attack of the crop. Antibiotic producing PGPR releases compounds that prevent the growth of the pathogens.

Application of PGPR

A. Biological Nitrogen Fixation

A number of bacterial species belonging to genera Azospirillum, Alcaligenes, Arthrobacter, Acinetobacter, Bacillus, Burkholderia, Enterobacter, Erwinia, Flavobacterium, Pseudomonas, Rhizobium and Serratia are associated with the plant rhizosphere and are able to exert a beneficial effect on plant growth. The important role is played by plants in selecting and enriching the types of bacteria by the constituents of their root exudates. The use of bio-fertilizer and bioenhancer such as N2 (nitrogen) fixing bacteria and beneficial micro-organism can reduce chemical fertilizer applications and consequently lower production cost. Utilization of PGPR in order to increase the productivity may be a viable alternative to organic fertilizers which also helps in reducing the pollution and preserving the environment in the spirit of an ecological agriculture.

Symbiotic Nitrogen Fixers

Two groups of nitrogen fixing bacteria have been studied extensively, which includes Rhizobia and Frankia. Frankia forms root nodules on more than 280 species of woody plants from 8 different families however, its symbiotic relationship is not as well understood. Frankia is known to form effective symbiosis with the species of Alnus and Casuarina. A number of individual species may improve plant nutrition by releasing plant growth regulators, siderophores and hydrogen cyanide or may increase phosphate availability.

1. Rhizobium: When rhizobia colonize the roots from non-legume plant in a non-specific relationship the strains from this genus may behave as PGPR. Inoculation of Rhizobium sp. causes a greater increase in growth and yield and the number of nodules per root system is significantly higher in plants inoculated with Rhizobium sp. compared to plants without Rhizobium sp. under field condition. In addition to their beneficial N2-fixing activity with legumes, rhizobia can improve plant nutrition by mobilizing inorganic and organic Phosphorous.

2. Bradyrhizobium: Bradyrhizobium species are Gram-negative bacilli (rod shaped) with a

single subpolar or polar flagellum. They are a common soil dwelling microorganism that can form symbiotic relationships with leguminous plant species where they fix nitrogen in exchange for carbohydrates from the plant. Like other rhizobia, they have the ability to fix atmospheric nitrogen into forms readily available for other organisms to use. They are slow growing in contrast to Rhizobium species, which are considered fast growing rhizobia.

B. Non-Symbiotic Nitrogen Fixers

Non-symbiotic nitrogen fixation has a great agronomic significance. One main limitation that it faces is the availability of carbon and energy source for the energy intensive nitrogen fixation process. However, this limitation can be compensated by moving closer to or inside the plants, viz. in diazotrophs present in rhizosphere, rhizoplane or those growing endophytically. Some important non-symbiotic nitrogen-fixing bacteria include Azoarcus sp., Gluconacetobacter diazotrophicus, Herbaspirillum sp., Azotobacter sp., Achromobacter, Acetobacter, Alcaligenes, Arthrobacter, Azospirillum, Azomonas, Bacillus, Beijerinckia, Clostridium, Corynebacterium, Derxia, Enterobacter, Klebsiella, Pseudomonas, Rhodospirillum, Rhodopseudomonas and Xanthobacter.

Plant Growth Producers: There are numerous soil microflora involved in the synthesis of auxins in pure culture and soil. The potential for auxin biosynthesis by rhizobacteria can be used as a tool for the screening of effective PGPR strains. Accumulating evidence indicates that PGPR influence plant growth and development by the production of phytohormones such as auxins, gibberellins, and cytokinins. The effects of auxins on plant seedlings are concentration dependent, i.e. low concentration may stimulate growth while high concentrations may be inhibitory. Different plant seedlings respond differently to variable auxin concentrations and type of microorganisms. The strains which produce the highest amount of auxins i.e. indole acetic acid (IAA) and indole acetamide (IAM) in non-sterilized soil, causes maximum increase in growth and yield of the crop. Even the strains, which produce low amounts of IAA, release it continuously, thus improving plant growth.

Siderophore Production: Iron is an essential growth element for all living organisms. The scarcity of bioavailable iron in soil habitats and on plant surfaces foments a furious competition. Under iron-limiting conditions PGPB produce low-molecular-weight compounds called siderophores to competitively acquire ferric ion. Siderophores (Greek: "iron carrier") are small, high-affinity iron chelating compounds secreted by microorganisms such as bacteria, fungi and grasses. Microbes release siderophores to scavenge iron from these mineral phases by formation of soluble Fe3+ complexes that can be taken up by active

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transport mechanisms. Biocontrol Agent: PGPR are indigenous to soil

and the plant rhizosphere and play a major role in the biocontrol of plant pathogens. They can suppress a broad spectrum of bacterial, fungal and nematode diseases. PGPR can also provide protection against viral diseases. The use of PGPR has become a common practice in many regions of the world. Greater application of PGPR is possible in agriculture for biocontrol of plant pathogens and biofertilization. A major group of rhizobacteria with potential for biological control is the Pseudomonades. Pseudomonas sp. is ubiquitous bacteria in agricultural soils. Pseudomonads possess many traits that make them well suited as biocontrol and growth-promoting agents. These include the ability to (i) grow rapidly in vitro and to be mass produced; (ii) rapidly utilize seed and root exudates; (iii) colonize and multiply in the rhizosphere and spermosphere environments and in the interior of the plant; (iv) produce a wide spectrum of bioactive metabolites (i.e., antibiotics, siderophores, volatiles, and growth-promoting substances); (v) compete aggressively with other microorganisms; and (vi) adapt to environmental stresses.

Phosphate Solubilizing Bacteria (PSB): Phosphorus (P) is major essential macronutrients for biological growth and development. Microorganisms offer a biological rescue system capable of solubilising the insoluble inorganic P of soil and make it available to the plants. The ability of some microorganisms to convert insoluble phosphorus (P) to an accessible form, like orthophosphate, is an important trait in a PGPB for increasing plant yields. The rhizospheric phosphate utilizing bacteria could be apromising source for plant growth promoting agent in agriculture. The use of phosphate solubilising bacteria as inoculants increases the P uptake by plants.

Antifungal Activity: PGPR improve plant growth by preventing the proliferation of phytopathogens and thereby support plant growth. Some PGPR synthesize antifungal antibiotics, e.g. P. fluorescens produces 2,4-

diacetylphloroglucinol which inhibits growth of phytopathogenic fungi. Certain PGPR degrade fusaric acid produced by Fusarium sp. causative agent of wilt and thus prevents the pathogenesis. Some PGPR can also produce enzymes that can lyse fungal cells. For example, Pseudomonas stutzeri produces extracellular chitinase and laminarinase which lyses the mycelia of Fusarium solani.

PGPR Action under Stressed Conditions: Abiotic stress factors include high and low temperature, salinity, drought, flooding, ultraviolet light, air pollution (ozone) and heavy metals. The yield losses associated with abiotic stresses can reach 50% to 82%, depending on the crop. Under high salinity, plants exhibit a reduced leaf growth rate due to decreased water uptake, which restricts photosynthetic capacity. Plant involves a number of metabolic and physiological changes in response to salt stress and water deficiency (drought). The inoculation of salt-stressed plants with PGPR strains alleviates the salinity stress in plants. Soil salinity is one of the most severe factors limiting nodulation, yield and physiological response. The synthesis and activity of nitrogenases in Azospirillum. brasilense is inhibited by salinity stress. In Azospirillum sp. there is an accumulation of compatible solutes such as glutamate, proline, glycine betaine and trehalose in response to salinity/osmolarity; proline plays a major role in osmoadaptation through increase in osmotic stress that shifts the dominant osmolyte from glutamate to proline in A. brasilense. Azospirillum-inoculated plants had more water content, higher water potential, and lower canopy temperature in their foliage. Hence, they were less drought-stressed than non-inoculated plants. The PGPR containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions such as flooding, heavy metals, phytopathogens, drought and high salt. Ethylene is an important phytohormone, but over-produced ethylene under stressful conditions can result in the inhibition of plant growth or death, especially for seedlings.


Biofertilizers in Organic Agriculture Suma C. Kammar and M. Shweta

Dept. of Agril. Microbiology, UAS, Raichur – 584 102 *Corresponding Author eMail: [email protected]

Organic farming has emerged as an important priority area globally in view of the growing demand for safe and healthy food and long term sustainability and concerns on environmental pollution associated with indiscriminate use of agrochemicals. Though the use of chemical inputs

in agriculture is inevitable to meet the growing demand for food in world, there are opportunities in selected crops and niche areas where organic production can be encouraged to tape the domestic export market.

Bio-fertilizers are being essential component

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of organic farming are the preparations containing live or latent cells of efficient strains of nitrogen fixing, phosphate solubilizing or cellulolytic micro-organisms used for application to seed, soil or composting areas with the objective of increasing number of such micro-organisms and accelerate those microbial processes which augment the availability of nutrients that can be easily assimilated by plants. Biofertilizers play a very significant role in improving soil fertility by fixing atmospheric nitrogen, both, in association with plant roots and without it, solubilise insoluble soil phosphates and produces plant growth substances in the soil.

Biofertilizers are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants’ uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil. They accelerate certain microbial processes in the soil which augment the extent of availability of nutrients in a form easily assimilated by plants. Very often microorganisms are not as efficient in natural surroundings as one would expect them to be and therefore artificially multiplied cultures of efficient selected microorganisms play a vital role in accelerating the microbial processes in soil.

Use of biofertilizers is one of the important components of integrated nutrient management, as they are cost effective and renewable source of plant nutrients to supplement the chemical fertilizers for sustainable agriculture.

Several microorganisms and their association with crop plants are being exploited in the production of biofertilizers. They can be grouped in different ways based on their nature and function.

N2 Fixing Biofertilizers

Free-living- Azotobacter, Beijerinkia, Clostridium, Klebsiella, Anabaena, Nostoc,

Symbiotic- Rhizobium, Frankia, Anabaena azollae

Associative Symbiotic- Azospirillum

P Solubilizing Biofertilizers

Bacteria- Bacillus megaterium var. phosphaticum, Bacillus subtilis, Bacillus circulans, Pseudomonas striata, Fungi- Penicillium sp, Aspergillus awamori

P Mobilizing Biofertilizers

Arbuscular mycorrhiza- Glomus sp., Gigaspora sp., Acaulospora sp., Scutellospora sp. & Sclerocystis sp., Ectomycorrhiza- Laccaria sp., Pisolithus sp., Boletus sp., Amanita sp, Ericoid mycorrhizae- Pezizella ericae, Orchid mycorrhiza- Rhizoctonia solani, Biofertilizers for Micro nutrients- Silicate and Zinc solubilizers- Bacillus sp.

Plant Growth Promoting Rhizobacteria: Pseudomonas- Pseudomonas fluorescens

Different Types of Biofertilizers

Carrier Based

Rhizobium: is a soil habitat bacterium, which can able to colonize the legume roots and fixes the atmospheric nitrogen symbiotically. The morphology and physiology of Rhizobium will vary from free-living condition to the bacteroid of nodules. They are the most efficient biofertilizer as per the quantity of nitrogen fixed concerned. They have seven genera and highly specific to form nodule in legumes, referred as cross inoculation group.

Azotobacter: Of the several species of Azotobacter, A. chroococcum happens to be the dominant inhabitant in arable soils capable of fixing N2 (2-15 mg N2 fixed /g of carbon source) in culture media. The bacterium produces abundant slime which helps in soil aggregation. The numbers of A. chroococcum in Indian soils rarely exceeds 105/g soil due to lack of organic matter and the presence of antagonistic microorganisms in soil.

Azospirillum: Azospirillum lipoferum and A. brasilense are primary inhabitants of soil, the rhizosphere and intercellular spaces of root cortex of graminaceous plants. They perform the associative symbiotic relation with the graminaceous plants. The bacteria of Genus Azospirillum are N2 fixing organisms isolated from the root and above ground parts of a variety of crop plants. They are Gram negative, Vibrio or Spirillum having abundant accumulation of polybetahydroxybutyrate (70 %) in cytoplasm. The organism proliferates under both anaerobic and aerobic conditions but it is preferentially micro-aerophilic in the presence or absence of combined nitrogen in the medium. Apart from nitrogen fixation, growth promoting substance production (IAA), disease resistance and drought tolerance are some of the additional benefits due to Azospirillum inoculation.

Cyanobacteria: Both free-living as well as symbiotic cyanobacteria (blue green algae) have been harnessed in rice cultivation in India. A composite culture of BGA having heterocystous Nostoc, Anabaena, Aulosira etc. is given as primary inoculum in trays, polythene lined pots and later mass multiplied in the field for application as soil based flakes to the rice growing field at the rate of 10 kg/ha. The final product is not free from extraneous contaminants and not very often monitored for checking the presence of desired algal flora.

Azolla: Azolla is a free-floating water fern that floats in water and fixes atmospheric nitrogen in association with nitrogen fixing blue green alga Anabaena azollae. Azolla fronds consist of sporophyte with a floating rhizome and small overlapping bi-lobed leaves and roots. Azolla is used as biofertilizer for wetland rice and it is known to contribute 40-60 kg N/ha per rice crop.

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Phosphate solubilizing microorganisms (PSM): Several soil bacteria and fungi, notably species of Pseudomonas, Bacillus, Penicillium, Aspergillus etc. secrete organic acids and lower the pH in their vicinity to bring about dissolution of bound phosphates in soil.

AM fungi: The transfer of nutrients mainly phosphorus and also zinc and sulphur from the soil milleu to the cells of the root cortex is mediated by intracellular obligate fungal endosymbionts of the genera Glomus, Gigaspora, Acaulospora, Sclerocysts and Endogone which possess vesicles for storage of nutrients and arbuscles for funneling these nutrients into the root system. By far, the commonest genus appears to be Glomus, which has several species distributed in soil.

Liquid Biofertilizers

Biofertilizers are such as Rhizobium, Azospirillum and Phosphobacteria provide nitrogen and phosphorous nutrients to crop plants through nitrogen fixation and phosphorous solubilization processes. These Biofertilizers could be effectively utilized for rice, pulses, millets, cotton, sugarcane, vegetable and other horticulture crops. Biofertilizers is one of the prime input in organic farming not only enhances the crop growth and yield but also improves the soil health and sustain soil fertility.

The advantages of Liquid Bio-fertilizer over conventional carrier based Bio-fertilizers are listed below:

1. Longer shelf life -12-24 months. 2. No contamination. 3. No loss of properties due to storage upto 45º C. 4. Greater potentials to fight with native population. 5. High populations can be maintained more than 109 cells/ml upto 12 months to 24 months. 6. Easy identification by typical fermented smell. 7. Cost saving on carrier material, pulverization, neutralization, sterilization, packing and transport. 8. Quality control protocols are easy and quick. 9. Better survival on seeds and soil. 10. No need of running Bio-fertilizer production units throughout the year. 11. Very much easy to use by the farmer. 12. Dosages is 10 time less than carrier based powder Bio-fertilizers. 13. High commercial revenues. 14. High export potential. 15. Very high enzymatic activity since contamination is nil.

Application of Biofertilizers

1. Seed treatment: One packet of the inoculant is mixed with 200 ml of rice kanji to make slurry. The seeds are mixed in the slurry then shade dried for 30 minutes. The shade dried seeds should be sown within 24 hours. One packet of the inoculant (200 g) is sufficient to treat 10 kg of seeds. 2. Seedling root dip: This method is used for transplanted crops. Two packets of the inoculants is mixed in 40 litres of water. The root portion of

the seedlings required for an acre is dipped in the mixture for 5 to 10 minutes and then transplanted. Main field application: Four packets of the inoculant is mixed with 20 kgs of dried and powdered farm yard manure and then broadcasted in one acre of main field just before transplanting.

Constraints in Biofertilizer Technology: Though the biofertilizer technology is a low cost, ecofriendly technology, several constraints limit the application or implementation of the technology the constraints may be environmental, technological, infrastructural, financial, human resources, unawareness, quality, marketing, etc. The different constraints in one way or other affecting the technique at production, or marketing or usage.

Technological Constraints: 1. Use of improper, less efficient strains for production. 2. Lack of qualified technical personnel in production units. 3. Production of poor quality inoculants without understanding the basic microbiological techniques. 4. Short shelf life of inoculants.

Infrastructural Constraints: 1. on-availability of suitable facilities for production. 2. Lack of essential equipments, power supply, etc. 3. Space availability for laboratory, production, storage, etc. 4. Lack of facility for cold storage of inoculant packets

Financial Constraints: 1. Non-availability of sufficient funds and problems in getting bank loans 2. Less return by sale of products in smaller production units.

Environmental Constraints: 1. Seasonal demand for biofertilizers. 2. Simultaneous cropping operations and short span of sowing/planting in a particular locality. 3. Soil characteristics like salinity, acidity, drought, water logging, etc.

Human Resources and Quality Constraints

1. Lack of technically qualified staff in the production units

2. Lack of suitable training on the production techniques

3. Ignorance on the quality of the product by the manufacturer

4. Non-availability of quality specifications and quick quality control methods

5. No regulation or act on the quality of the products

6. Awareness on the technology 7. Unawareness on the benefits of the

technology 8. Problem in the adoption of the technology by

the farmers due to different methods of inoculation

9. No visual difference in the crop growth immediately as that of inorganic fertilizers.

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Diagnosis of Plant Viruses Using Molecular Techniques Dr. H. N. Kamble and A. G. Tekale

Assistant Professor, Department of Plant Pathology, College of Agriculture, Tondapur, Hingoli (M.S.)

Plant treatments after infection with virus diseases often do not lead to an effective control. Accordingly, virus diseases are managed most effectively if control measures are applied before infection occurs. Therefore, accurate diagnosis of virus diseases and diseases in general, is a first important step for any crop management system. The use of healthy (virus free) plant propagation material is among the most effective approaches to adopt by farmers. One of the elements essential for successful certification programs to produce such propagation material is the availability of sensitive diagnostic methods. Few decades ago, virus detection was based mainly on biological techniques which are too slow and not amendable to large scale application. Advances in molecular biology and biotechnology over the last three decades were applied to develop rapid, specific and sensitive techniques for the detection of plant viruses. Therefore, this article will summarize the development and use of the main immunological and nucleic acid-based methods for virus detection.

Immunological-Protein Based Methods

ELISA (Enzyme Linked Immunosorbent Assay): It was first developed by Voller and his co-workers. It has been used as a diagnostic tool in medicine and plant pathology, as well as a quality control check in various industries. During the last three decades, it was widely used method for the detection of viruses that is highly sensitive, simple, fast and most importantly has the ability to quantify virus content in plant tissue. The binding of the virus and specific antibody is made visible through an antibody tagged with an enzyme which can react with a substrate to produce a colored, water soluble product. The first reported method was the double antibody sandwich ELISA (DAS-ELISA) where the antibody is bound to the solid phase (e.g. polystyrene micro titer plate), then the test samples, enzyme labeled antibody and the substrate are added sequentially, with unbound material removed by washing between steps (Clark and Adams, 1977). In a positive test, the substrate solution turns colored, whereas a negative test remains colorless. The color intensity, which is proportional to virus contents, can be measured spectrophotometrically. Since the report of Clark and Adams in 1977, many ELISA variants were reported, by using different enzymes or universal conjugates. In this later case the test is known as triple antibody sandwich ELISA (TAS-ELISA). In other variants, the first step of coating the solid phase with antibodies is

deleted, and consequently virus particles are adsorbed directly on the solid phase, and the test is known as direct antigen coating ELISA (DAC-ELISA). In addition, immunoassay sensitivity can be enhanced by the use of different amplification systems, with avidin-biotin being the most common.

In addition to the polystyrene plates, a number of solid phase supports were found adequate. Assays in which antibodies or virus particles are bound to nitrocellulose membrane filters were used and known as immunoblots or dot-blots. Dot blot ELISA tends to be rapid, easy to perform and conservative of reagents and often more sensitive than ELISA carried out in a micro titer plate (Banttari and Goodwin, 1985). Immunoblot assays use the same reagents used in micro titer plate ELISAs, except that the substrate produces an insoluble product which precipitates onto the membrane. Positive reactions can be determined visually.

An interesting development was the printing of plant parts cut surfaces on nitrocellulose membranes and then the test continues in a way similar to dot-blot assays. The procedure is known as the tissue-blot immunoassay (TBIA) (Lin et al., 1990). The major advantage of this test was the elimination of sap extraction, which is the most time consuming step in all previous techniques. In addition, once the plant tissue is blotted on the NC membrane, the test can be completed either few days or few months later. This is a big advantage in remote places, where facilities for processing NC membranes do not exist. In such locations, samples can be printed on NC membranes and then sent/mailed to distant locations for processing.

As a result of the progress made in the last two decades in the medical diagnostic industry, a number of procedures and devices have been developed that increase speed, sensitivity and ease of use of immunoassays in the field. One of these approaches for the detection of plant viruses is the “dipstick”, developed earlier for the physicians’ office and home use, is now being used for the detection of various pathogens, including viruses, in the field (Rowland et al., 2005). Small plant tissue is placed in an extraction bag which contains an extraction buffer, then the bag is rubbed with a pen or blunt object to crush the samples, the tip of a strip (e.g. Immuno Strips form Agdia) is inserted in a vertical position into the extract and the result will appear as a colored line within 3-5 minutes.

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Molecular-Nucleic Acid Based Methods

1. Dot-blot assay: This development in nucleic acid hybridization technology offers a good potential for virus detection. The target viral nucleic acid from a plant sample is spotted onto a solid matrix, commonly nylon or nitrocellulose membranes, and bound by baking. Free binding sites on the membrane are blocked with a non-homologous DNA and a protein source. Thereafter, hybridization with a labeled probe is carried out. The label is then detected by autoradiography (for radioactive probes), or by a colorimetric reaction if an enzyme label is used. The sensitivity of dot-blot hybridization is about the same as ELISA (Sela et al., 1984).

2. PCR (polymerase chain reaction): It has been used as the new standard for detecting a wide variety of templates across a range of scientific disciplines, including virology. The method employs a pair of synthetic oligonucleotides or primers, each hybridizing to one strand of a double stranded DNA target, with the pair spanning a region that will exponentially reproduced. The hybridized primer acts as a substrate for a DNA polymerase, which creates a complementary strand via sequential addition of deoxynucleotides. The process can be summarized in three steps: (i) dsDNA separation at temperatures above 90ºC, (ii) primers annealing at 50-75C, and (iii) optimal extension at 72-78ºC. The rate of temperature change, the length of the incubation at each temperature and the number of times each cycle is repeated is controlled by a programmable thermal cycle. The amplified DNA fragments will then be separated by agarose gel electrophoresis and the bands are visualized by staining the resulting bands with ethedium bromide and irradiation with ultraviolet light. The specificity of PCR testing is dependent on the primer sets used. There are virus species specific primers and genus specific primers. The above procedure work well for DNA viruses (e.g. viruses of the genera Geminivirus, Nanovirus and Caulimovirus). For RNA viruses, an initial step to transcribe the RNA viral genome to its complementary DNA (cDNA) (Reverse Transcription) by using the enzyme reverse transcriptase (RT) is needed. Accordingly, the PCR procedure followed for the detection of RNA viruses is known as RT-PCR.

3. Real time PCR: The ability to visualize the progress of amplification in a quantitative manner was welcomed by research workers. This approach has provided insight into the kinetics of the PCR reaction and it is the foundation of “real time” PCR. The monitoring of accumulating amplicon in

real time PCR has been possible by the labeling of primers, probes or amplicon with fluorogenic molecules. The increased speed of real time PCR is largely due to reduced cycle times, removal of post-PCR detection procedures and the use of fluoregenic labels and sensitive methods of detecting their emissions. The reduction in amplicon size generally recommended by the inventors of commercial real-time assays may also play a role in this speed, but decreased product size does not necessarily improve PCR efficiency. Real time PCR has proven increasingly valuable diagnostic tool for plant viruses. However, it requires an initial high capital investment to acquire the needed equipment, as compared to other techniques.

4. Confirmation of TBIA results by PCR: In virus identification, especially when a virus is detected for the first time in a region, it is essential to confirm the results obtained by one test (e.g. TBIA) by applying another technique on the same sample. Recent research results showed that when TBIA positive samples where cut from the NC membrane and tested by PCR, virus-specific amplicons were produced. In addition, when the PCR test was conducted on few months old processed NC membranes, amplification of the target sequence was clearly obtained. This is an indication that the TBIA procedure had no effect on the viral genome, and it remained stable for a long period. To cut down on cost, it is possible that in large scale operations (surveys, certification program), it is possible to test the samples in the first round by TBIA, and only those samples positive for a specific virus can be re-tested by PCR.

References Clark, M.F. and Adams, A.N. 1977. Characteristics of

the microplate method of enzyme-linked immunosorbent assay for the detection of plant viruses. Journal of General Virology, 34: 475-483.

Banttari, E.E. and Goodwin. P.H. 1985. Detection of potato viruses S, X, and Y by enzyme-linked immunosorbent assay on nitrocellulose membranes (dotELISA). Plant Disease, 69: 202-205.

Lin, N.S., Hus, Y.H. and Hsu, H.T. 1990. Immunological detection of plant viruses and a mycoplasmalike organism by direct tissue blotting on nitrocellulose membranes. Phytopathology, 80: 824-829.

Rowland, D., Dorner, J., Sorensen, R., Beasley, J.P. and Todd, J. 2005. Tomato spotted wilt virus in peanut tissue types and physiological effects related to disease incidence and severity. Plant Pathology, 54: 431-440.

Sela, I., M. Reichman and A. Weissbach. 1984. Comparison of dot molecular hybridization and enzymelinked immunosorbent assay for detecting tobacco mosaic virus in plant tissues and protoplasts. Phytopathology, 74: 385-389.

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14. NANOTECHNOLOGY 14866

Nanotechnological Approaches for Improved Nutrient Use Efficiency

Bisweswar Gorain1 and Srijita Paul2

Ph.D. Scholars, 1Division of Soil Science and Agricultural Chemistry, IARI, New Delhi 2Department of Agronomy, BCKV, Mohanpur, WB

Nutrient management has been the core sector in crop production. The most efficient of the methods have been the one which are capable of providing nutrients at the right time and in the right proportion. Nanotechnology is one such system which ensures supply of nano sized nutrients with very high use efficiency and can be harnessed to increase productivity and conserve precious nutrients. It provides nutrients through the mechanism of slow release of nano particles. Nanotechnology has various applications. Nano clay imparts slow release property to fertilizers and enhances the water holding capacity of soil and thus indirectly improves nutrient use efficiency. The nutrient use efficiency increases on the application of nano fertilizers primarily due to their nano sizes which reduces leaching and volatilization losses. Therefore, nano particles may facilitate development of agricultural management systems that ensure long term sustainability of soil resources.

Importance and Role of Nanofertilizers in Improvement of Nutrient use Efficiency

The development of slow/controlled release fertilizers has become critically important for promoting the development of environment friendly and sustainable agriculture. Indeed, nanotechnology has provided the feasibility of exploiting nano-scale or nano-structured materials as fertilizer carriers or controlled-release vectors for building of so-called “smart fertilizer” to enhance nutrient use efficiency and reduce costs of environmental protection.

In Nanofertilizers, Nutrients can be

Encapsulated by nanomaterials,

Coated with a thin protective film,

Delivered as emulsions or nanoparticles.

Released in a controlled rate to increase Nutrient Use Efficiency.

Nano-Clay as Carrier of Urea

The layered clays like montmorilonite and kaolinite are made of nanolayers.

Nano clay is the most common nano-particle used to produce Controlled Release Fertilizers (CRFs).

Montmorillonite is the most commonly used clay mineral consisting of ~ 1 nm thick aluminosilicate layers stacked in ~ 10 µm-sized multilayers.

Large surface areas and reactivity of nanolayers is much greater than that of micro size materials.

Because of these features nanolayers is a suitable carrier or reservoir of fertilizers.

FIG. 1: Urea loaded nano-montmorillonite

Nano-K fertilizer is a better source of potassium not only in terms of enhanced grain yield of rice but also maintenance of soil exchangeable K content as well. Application of 20 kg nano K2O/ha as basal dose showed similar yields as MOP at 40 kg K2O/ha. (Sirisena et al., 2013)

Use of nano zeolite fortified with gypsum nano-fertilizer formulation is capable of releasing nutrients between 1000-1200 hrs while conventional fertilizer could release only up to 300-350 hrs. The data suggested that nano formulation will be very ideal to regulate release of nutrients. (Preetha et al., 2014)

Importance of Carbon Nanotube in Slow Release of Fertilizers

The use of carbon nanotube has become a new trend to save fertilizer consumption and to minimize environmental pollution. Due to its high surface area and chemical activity, the application domain of nano-carbon has significantly expanded in agricultural research. The nano-carbon is used as coating material for slow-released fertilizer and its incorporation into slow-released fertilizer not only improve nutrient use efficiency but also helps in reducing water pollution. Wu (2013) found that the rice grain yield and nitrogen use efficiency were increased significantly after applying slow-release fertilizer treated with nano carbon. Thus nano nutrients can be effectively used for efficient

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management of nutrient resources.

References Preetha, P., Subramanian, K. S. and Sharmila, R. C.,

2014, Sorption characteristics of nano zeolite based slow release sulphur fertilizer. Int. J. Dev. Res. 4(2): 225-228

Sirisena, D. N., Dissanayake, D. M. N., Somaweera,

K. A. T. N., Karunaratne, V. and Kottegowda N., 2013, Use of nano K fertilizer as a source of potassium in rice cultivation. Annals Sri Lankan Dept. Agril. 15: 257-262

Wu, M.Y., 2013, Effects of incorporation of Nano-carbon into slow released fertilizer on Rice yield and Nitrogen Loss in surface water of paddy soil. Adv. J. food sci. and Tech. 5(4): 398-403.

15. AGRONOMY 13704

Use of Sensors for Site Specific Management in Agriculture Ashutosh S. Dhonde and Sunil D. Thorat

Ph.D. Scholar, Department of Agronomy, Mahatma Phule Krishi Vidyapeeth, Rahuri, MS - 413 704

Sensor Definition

Sensor is a device that detects event and provides a corresponding output generally as an electrical or optical signal e.g. Thermocouple, thermometer, line quantum sensor, chlorophyll meter.

Introduction

Large scale field-to-field variability of soil N supply restricts efficient use of N fertilizer when broad-based blanket recommendations are used in sugarcane.

The cultivars varying in their maturity status, also often show differential response to N fertilizer application.

Besides, many a times, to ensure higher yields, farmers advertently apply higher fertilizer N doses than the recommended ones.

Innovative fertilizer management has to integrate both preventive and field specific corrective N application strategies to increase the profitability of sugarcane through enhanced nitrogen use efficiency.

Sr. No.

Determination Sensors

1. Plant N Leaf polyphenolic sensors

2. Vegetation indices NDVI (Normalized difference veg. index)

3. Crop water stress measurement

Wireless sensor network

4. Canopy water content Hyper spectral sensor

5. Soil moisture Ground penetrating rodar (GPR)

6. Hard pan depth GPR

7. Crop yield Grain yield sensor

8. NH3 level IOAS (Integrated optical ammonia sensor)

9. Chlorophyll index Leaf chlorophyll portable meter

Soil nutrient sensors are used to detecting the soil fertility status. With help of these soil nutrient sensor the fertilizer rate is determined for a place where nutrient is deficient. There are different types of sensor as listed below

Water stress

Weed Infestation

Grain moisture levels

Soil depth

Soil nitrogen

Soil organic matter

Weather Forecasting

Several organization all over the world measure weather elements and forecast weather conditions. Based on time and duration of forecasting period divided into short range, medium range and long range weather forecast. Short range weather for casts are for a day or two. Medium range for 3 to 4 days to two weeks while long range for more than four weeks. Weather forecasting is useful to farmers, irrigation engineers, mariners, aviation engineers.

Site-Specific Management: Site-specific management (SSM, also known as precision farming, precision agriculture, prescription farming, etc.) is a management strategy that seeks to address within-field variability and to optimize inputs such as pesticides and fertilizers on a point-by-point basis within a field.

Flat-Rate Fertilizer Application

High-yielding soils, represented by the left side of the graph, receive the same amount of fertilizer as the perennially low-yielding regions of the field, represented by the right side of the graph. The variation in yield leads to a variation in plant nutrient uptake throughout the field. The result is

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lost yield potential in some areas and wasted fertilizer in others.

Grid Sampling

Grid sampling, a field is divided into sections or “grids” of a specified and manageable size - typically 1.6 acres each.

A representative sample is then acquired from each grid for an individual test.

The sampling is done using a GPS receiver and a computer to map the field, position the samples, and record their locations.

These geo-referenced samples are then sent to a soil testing lab for analysis.

Variable-Rate Fertilizer Application

Fertilizer variably-applied, based on grid sample data. Instead of the fertilizer application rate being constant across the field, low yielding sites receive reduced rates, allowing plants to utilize nutrients stored in the soil. High yielding sites receive greater amounts of fertilizer to accommodate greater plant nutrient uptake and higher yields.

16. AGRONOMY 14362

Crop Modeling in Agriculture: Advantage and Demarcation Mundhe S. G.1*, Khazi G. S.2 and D. A. Sonawane3

1M.Sc. Scholar, Department of Agril. Meteorology, 3Associate Professor, Department of Agronomy, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra, 2Ph.D. Scholar, Department of Agronomy,

Vasantrao Naik Marathwada Krishi Vidyapeeth, Parhani (MS) – 431 402 *Corresponding Author eMail: [email protected]

A model is a schematic representation of the conception of a system or an act of mimicry or a set of equations, which represents the behavior of a system. The rediscovered importance of the effect of weather and climate on crop production has brought about numerous research projects and publications dealing with crop weather relationships at different scales. Various statistical and mathematical techniques for developing these relationships have been used and the term Crop Model has emerged.

Studies on crop production are traditionally carried out by using conventional experience-based agronomic research, in which crop production functions are derived from statistical analysis without referring to the underlying biological or physical principles involved. The application of correlation and regression analysis has provided some qualitative understanding of the variables and their interactions that were involved in cropping systems and has contributed to the progress of agriculture science.

However, the quantitative information obtained from this type of analysis is very site specific. The information obtained can only be reliably applied to other sites where climate,

important soil parameters and crop management are similar to those used in developing the original functions. Thus, the quantitative applicability of regression based crop yield models for decision making is severally limited. In addition, because of the unavoidable variability associated with weather, more than 10 years is required to develop statistical relationships that are useful in agricultural decision making. Ref Statistical evidence based on long-term studies generally show that more than 40% of the total variation is usually associated with experimental error. Advances in computer technology have made possible the consideration of the combined influence of several factors in various interactions. As a result, it is possible to quantitative combine the soil, plant, and climatic systems to more accurately predict crop yield. Thus with the availability of inexpensive and powerful computers and with the growing popularity of the application of integrated systems to agricultural practices, a new era of agricultural research and development is immerging. Computerized decision support system that allow users to combine technical knowledge contained in crop growth models with economic consideration and

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environment impact evaluation are now available.

Crop Models and its Applications

A validated dynamic crop growth model is the best operational tool, it can calculate the development and growth of crop under variety of climatic conditions, management practices and different soil conditions. Models are a mathematical representation of a real world system. Crop model in general calculate or predict crop yield as a functions of weather condition, soil conditions, crop management scenarios.

When the farmers have the difficult task of managing their crops on poor soils in harsh and risky climates. When scientists and research managers need tools that can assist them in taking an integrated approach to finding solutions in the complex problem of weather, soil and crop management. When policy makers and administrators need simple tools that can assist them in policy management in agriculture.

Application/ Advantages

Simulation modeling is increasingly being applied in research teaching, farm and resource management and policy analysis and production forecasts. A modeler can solve most of the difficulties encountered by farmer, research, crop system management, and policy analysis.

1. integration of knowledge across disciplines 2. Research understanding 3. Seed rate to be utilized 4. Row spacing or crop geometry 5. fertilizer dose and application 6. Irrigation and its stage of application

7. Improvement in experiment documentation and data organization

8. Climate change projections 9. Yield forecasting 10. Yield analysis 11. Site - specific experimentation 12. Breeding and introduction of new crop variety 13. Scoping best management practices

Crop Model Demarcation

Errors in input data, in measurement data or bias in field growth data or final measured yields may present problem leading to a failure of crop model.

There is no single, accepted statistic or test that determines weather or not a model is valid.

Model is based on many empirical relationships, hypotheses, assumptions etc. and therefore always requires calibration, testing and validation for site specific application.

Models are approximations of reality; they cannot precisely represent natural systems.

References Baier, W. 1979. Note on terminology of crop weather

models. Agriculture Meteorology, 20: 137-145. Ritchie, J.T. 1994. Classification of Crop Simulation

Models in Crop Modelling and Related environmental data, pp 3-14. (in) A focus on Applications for Arid and Semi-arid Regions in Developing Countries. CODATA Monograph series, vol. 1.

Thornley, J.H.M. 1976. Mathematical Models in Plant Physiology, pp 1-3. Academic Press, London.

Yaranttan, G.A. 1971. Mathematical Representations and Models in Plant Ecology: Response to a note. Mead, r., J. Ecol. 59: 221-224

17. AGRONOMY 14509

Resource Conservation Technologies for Enhancing Productivity of Legume Based Cropping Systems

*Sunil Kumar1, Vikram Kumar1 and Rajesh Kumar Singhal2 1Department of Agronomy, 2Department of Plant Physiology

Institute of Agricultural Science, BHU, Varanasi-221005 *Corresponding Author eMail: [email protected]

INTRODUCTION: Rice and wheat are the two major food crops of India. Therefore, primary food security concerns are focused on improving and sustaining their productivity. With the advent of the “Green Revolution”, these two crops have come to occupy a significant area in the country. Of late, concerns have been expressed that the rice wheat growing areas are developing a so-called “fatigue”, due to continuous uninterrupted cultivation of this very exhaustive cereal-cereal (rice-wheat) cropping system. Inclusion of pulses in rice-wheat system increased the system productivity besides improving the soil fertility. Inclusion of rabi pulses significantly increased the productivity of succeeding rice crop in comparison

to wheat. Similarly, the yield of wheat was improved significantly after kharif legumes especially mungbean, soybean and groundnut than maize. Kharif pulses particularly cowpea and pigeonpea + urdbean/mungbean contributed an equivalent of 40 kg N/ha to subsequent cereal crops.

Resource Conservation Technologies (RCTs): RCT’s refers to the practice that enhances resource or input-use efficiency such as zero or reduced tillage, new varieties, laser land leveling, bed and furrow configuration for planting crops etc.

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Practices of RCT’s in Legume Based Cropping System

Sequential Cropping: Sequential cropping is a kind of multiple cropping system in which two or more crops are grown in sequence within a year, once crop being sown after the harvest of the other crop. e.g. Rice-wheat-mungbean sequence cropping.

Intercropping: Intercropping is the practice of growing two or more crops in proximity. The most common goal of intercropping is to produce a greater yield on a given piece of land by making use of resources that would otherwise not be utilized by a single crop. Pulses are generally intercropped with coarse cereals and oilseeds under rainfed condition in our country. The slow initial growth habit and deep tap root system makes these crops more suitable for intercropping with cereals and oilseed crops than any other crop. Apart from increasing profitability and resource use efficiency, pulses as intercrop act as safe guard under unprecedented moisture stress condition.

Utilization of rice-fallows: The timely sowing of pulses is crucial in view of the moisture deficit during critical periods in the rice fallow conditions. The farmers usually broadcast the seeds to take advantage of residual moisture in rice fallow. The mechanization in such conditions needs development, standardization and adoption of farm machinery for direct seeding under residue retained on the soil surface. Double cropping is not feasible due to unavailability of irrigation water and delay in vacating the field after rice. These mono-cropped areas can be used for double cropping by relay planting small seeded lentil or low toxin (BOAA) containing lathyrus genotypes (e.g., Bio L 212).

Utilization of rice-fallows: The timely sowing of pulses is crucial in view of the moisture deficit during critical periods in the rice fallow conditions. The farmers usually broadcast the seeds to take advantage of residual moisture in rice fallow. The mechanization in such conditions needs development, standardization and adoption of farm machinery for direct seeding under residue retained on the soil surface. Double cropping is not feasible due to unavailability of

irrigation water and delay in vacating the field after rice. These Mono cropped areas can be used for double cropping by relay planting small seeded lentil or low toxin (BOAA) containing lathyrus genotypes (e.g., Bio L 212).

Inclusion of mungbean in rice-wheat system: Inclusion of (dual purpose) mungbean during summer months in rice-wheat system may help in increasing the productivity of the system, soil fertility, pulse availability and additional income. Mungbean can be grown after the harvest of wheat and before transplanting/ sowing of rice during April to June, The matured pods are picked up and the residues left ploughed down into the soil.

Brown manuring: Direct seeding of rice co-cultured with Sesbania; inter-cropped Sesbania is killed with 2,4-D (dose @ 0.5 kg a.i./ha) after 25-30 days of growth controls weeds, add organics and nutrients for healthy growth of rice crop

RCTs Techniques in Legume Based Cropping Systems

Laser land leveler: Land leveling is necessary for good agronomic, soil and crop management practices. It saves irrigation water, facilitates field operations and increases yield and quality of the produce. Leveled land also helps in smooth operations of various farm machineries during field operations.

Residue Management and Pulses: Residues are important in nutrient distribution and plant growth and they affect the amount of soil nutrients available to crops. Plant residues influence N cycling in soils because they are primary sources and sinks for C and N. Residues allow N to be available to plants for longer period of time through initially immobilizing and then gradually mineralizing N. However, in many parts of the tropics, crop residues are burnt in the field due to the ignorance of farmers about their value and lack of proper technology for Insitu incorporation of residues. One tonne straw on burning releases 3 kg particulate matter, 60 kg CO, 1460 kg CO2, 199 kg ash and 2 kg SO42-. The heat from burning cereal straw can penetrate into soil up to 1 cm, elevating the temperature to as high as 42.2 oC. Bacterial and fungal populations are decreased immediately upon burning.

Legumes under Raised Bed Planting System: Technology of raising row crops on beds and furrows system is gaining popularity amongst the progressive farmers, mainly because the cost of crop production is considerably reduced as a result of minimum tillage, water saving etc.

Direct drilling (No-Till Drilling): It is a practical tool to use crop residues and explore its advantages. Rabi pulses after rice are generally delayed due to late harvesting of rice, soil wetness, poor rice residue management and multiplicity of tillage operations, scarcity of power source and appropriate farm equipment during peak hours

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and sometime even arrivals of rain in the month of November.

Turbo Happy Seeder: Happy Seeder was developed by PAU, Ludhiana, in collaboration with Australian Centre for International Agricultural Research was developed for residue covered fields. This handles high rates of residue and seeds either on beds or on the flat. A combination of two machines, a forage harvester and a zero tillage drill using inverted T winged openers. The chopped material is blown directly behind the drill and floats down as mulch. The ‘Turbo Happy Seeder’ is a modified, advanced and light weight version of the ‘Happy Seeder’ to plant in presence of loose and or anchored residues. Turbo seeder differs from Happy Seeder in type of

the cutting blades, provision for adjustment of the rows, seed metering system and is lighter in weight. This machine works satisfactorily in combine harvested fields.

Conclusion: RCT’s with inclusion of pulses enhances crop productivity and sustainability. Zero tillage and bed planting are the successful techniques for timely sowing of grain legumes after rice harvest and or in rice fallows. Legume inclusion in crops and cropping systems improve N economy, P availability, buildup of organic matter and soil health. RCT’s with inclusion of pulses for intensification /diversification of the underutilized land and RW system contributed to increased net return and sustainability of the cropping system

18. AGRONOMY 14696

Agronomic Practices used in Saving of Water Dr. R. Prakash

Agricultural Officer and Research Associate, Tamil Nadu Irrigation Management Training Institute, Tiruchirapalli – 620 015

India being an agriculture country should have a good respect towards conservation strategies especially of water. Already we are suffering from a great stress of water scarcity. Each and every drop of water is important for us but unfortunately because of carelessness, we often waste huge amount of water. It is necessary to save water for sustainable agriculture. The agronomic practices such as deep summer ploughing, digging farm pond, contour ploughing, planting of vetiver, soil mulching, seed hardening techniques, etc will helps in controlling soil erosion and improves the soil water conservation.

Summer Ploughing: Perform deep summer ploughing (off season tillage) with pre-monsoon showers (During May) to recharge the soil profile. It facilitates to sow the crops immediately after onset of southwest monsoon. Off season tillage increases water content of soils and reduces runoff. It also reduces pest and weed infestation. The number and depth of ploughing depends on weed intensity. At best two summer ploughings are done prior to advent of monsoon at an interval of 15-20 days. Third ploughing can be done once with the help of harrow or cultivator to pulverize the soil and prepare field beds for sowing/transplanting soon after the first monsoon rain.

Farm Pond: This has been evolved by experience of farmers and is an age-old practice. Farm pond is constructed at lower gradient of the field in order to catch the runoff water from the higher gradient. This practice helps to increase the ground water level, further downstream. The yield of bore well has increased during summer season for growing crops.

Contour Ploughing: Contour ploughing or

contour farming or Contour bunding is the farming practice of plowing and/or planting across a slope following its elevation contour lines. These contour lines create a water break which reduces the formation of rills and gullies during times of heavy water run-off; which is a major cause of soil erosion. Contour farming is considered an active form of sustainable agriculture.

Planting of Vetiver (Chrysopogon zizanioides): Vetiver system could be effectively used in tea plantations for soil and moisture conservation and a live edge of vetiver could be established in place of stone revetments. Twenty five to thirty cm long tillers separated from well-grown clumps are to be planted at a spacing of 15-20 cm in order to form a thick hedge in areas where it is desired. The biomass generated from these plants serves as an excellent mulching and thatching material in tea plantations. Vetiver grows so densely that it can block the spread of other grasses including some of the world’s worst creeping grasses.

Seed Hardening: The pre-sowing seed hardening with chemicals is one of the simple techniques being employed to modify the marpho-physio-biochemical nature of seed, so as to induce the characters that are favorable for drought resistance. A day before sowing seeds could be soaked in water and CaCl2 (2%) or KH2PO4 (1%) or KCL (0.1%) solution for 2-3 hours. Later seeds will be dried under shade and used for sowing.

Mulching: Mulching is an age old practice of mixing dried leaves, twigs, stalk etc into the soil to improve its fertility condition and conserve moisture. It is common in organic cultivation methods. In modern conventional methods plastic sheets are being used. The sheets are laid on the

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field by a machine on top of the furrows and seedlings are planted in small holes made on the sheets. Plastic sheets have been found to conserve soil moisture because the water that gets evaporated from the soil in the open condenses on the lower part of the sheet as small droplets and

falls back into the soil. Mulching helps in minimizing the pests and viral diseases. The agricultural produces obtained are of better quality and colour, which fetch better price in the market.

19. AGRONOMY 14729

Global Warming and Crop Production Indu Bala Sethi1 and Mahesh Jajoria2

Research Scholar1, Department of Agronomy, G.B. Pant University of Agriculture & Technology, Pantnagar, 263145

Research Scholar2, Department of Soil Science, S.K.N. Agriculture University, Jobner, 303329 *Corresponding Author eMail: [email protected]

INTRODUCTION: Solar radiation passes through the atmosphere and warms the Earth’s surface. The Earth emits thermal radiation (also called infrared radiation) back to space, part of which is absorbed by the molecules of “greenhouse gasses” (water vapor, H2O; carbon dioxide, CO2; some other micro gases) in the atmosphere and warms the atmosphere. This warming effect of the greenhouse gases is called the “Greenhouse Effect”. A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs (chlorofluorocarbons), and other pollutants. The “greenhouse effect” & global warming are not the same thing. Global warming refers to a rise in the temperature of the surface of the earth. An increase in the concentration of greenhouse gases leads to an increase in the magnitude of the greenhouse effect. (Called enhanced greenhouse effect) This results in global warming. Global temperature during the 20th century increased by 0.6 ± 0.2°C @ of 0.17°C per decade since 1950.

Natural Greenhouse Effect: Due to greenhouse gases present for natural reasons; these gases (viz. CO2) were in the atmosphere (except CFCs) long before human beings came on the scene.

Enhanced Greenhouse Effect: The additional greenhouse effect caused by the additional greenhouse gases in the atmosphere due to human activities (fossil fuel burning; deforestation, etc) If there were no greenhouse gases (hence no greenhouse effect) the Earth’s temperature would be -18°C (not +15 °C as it is at present)

History of Climate Change and Agriculture

1827: Fourier pointed out the similarity between the blanketing effect of greenhouse gases in the atmosphere and what happens in a real greenhouse, hence the name: Greenhouse Effect.

1860: Tyndall measured the actual absorption of infrared radiation by CO2 and H2 O.

1896: Arrhenius calculated the effects of increasing greenhouse gases in the atmosphere; estimated the magnitude of global warming due to doubling of CO2.

Greenhouse effect is real; without it, the Earth would be uninhabitable.

TABLE 1: Greenhouse gases and their contribution to global warming (IPCC, 2007)

Greenhouse gases

Atmospheric conc. (ppm)

GWP (relative to CO2)

Sources

CO2 379 1 Fossil fuel combustion (80%), deforestation, burning, etc.

CH4 1.72 32 Biomass decomposition, wetland paddies, swamps, marshes, peat lands, etc.

N2O 0.31 150 Fertilizer use, fossil fuel combustion, biomass burning flooded soil

O3 Variable 2000 Reactions involving pollutants such as CH4, NO2, CFCs and sunshine

CFCs <0.0005 10,000 Aerosols, refrigerator

The temperature of the earth is directly related to the energy input from the Sun. Some of the Sun’s energy is reflected by clouds. Other is reflected by ice. The remainder is absorbed by the earth. If amount of solar energy absorbed by the earth is equal to the amount radiated back into space, the earth remains at a constant temperature. However, if the amount of solar energy is greater than the amount radiated, then the earth heats up. If the amount of solar energy is less than the amount radiated, then the earth cools down. To a certain degree, the earth acts like a greenhouse. Energy from the Sun penetrates the glass of a greenhouse and warms the air and

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objects within the greenhouse. The same glass slows the heat from escaping, resulting in much

higher temperatures within the greenhouse than outside it.

FIG. 1: Potential impacts of global warming on the agricultural sector (Gill et al, 2000)

Impact on Crop Production

High Temperature

Positive impact: – Reduced Cold & frost event

Negative impact: – Reduced yield due decrease grain filling

period – Increase respiration – Increase extreme weather condition i.e.

drought, heat wave – Increase evaporative losses

High CO2

Decrease evaporative losses

Increase yield in c3 plants e.g. rice & wheat

Adverse effect on quality of fruits

Other

Increase rate of organic matter decomposition

Lower organic matter content & quality

Decrease nitrogen availability

Extent of soil erosion

Salt –water problem in coastal land

Changes in seasonal precipitation & patterns

Moisture stress

Lowering water table

Melting of glacier increase water in rivers

Increase runoff in wet season

Impacts of Global Warming

CO2 Effects on Yield Components and Grain Composition Affecting Quality

Doubling of CO2 concentration will increase photosynthesis of C3 crop species by 30–50%.[2–4] The primary enzyme in leaf photosynthesis of C3 plants, ribulose 1,5- bisphosphate carboxylase/oxygenase (Rubisco), can bind is maintained only slightly lower (10%) than would exist at ambient CO2. Although crop transpiration might decrease slightly in elevated CO2, water use will increase if temperatures rise.

FIG. 2: Rising CO2 concentrations stimulate photosynthesis in many crops

FIG. 3: Schematic effect of CO2 concentrations on C3 and C4 plants (after Wolfe and Erickson, 1993). The main mechanism of CO2 fertilization is that it depresses photo-respiration, more so in C3 than in C4 plants

CO2 Effects on Yield Components and Grain Composition Affecting Quality

Since several significant impacts of CO2, exposure system, rooting volume or interactions between these parameters were observed for grain quality traits, the data were split for further evaluation into groups depending on rooting volume and exposure system. In all treatments, there was an overall increase in TGW in response to elevated CO2, except for the observations in OTCs, when experiments were conducted in pots. Nagarajan et al., 2009 the field work was carried out at the experimental farm, Division of Genetics, Indian Agricultural Research Institute (IARI), New Delhi,

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India during 2005. Five rice cultivars, three Basmati rice cultivars (Pusa Sugandh-2, Pusa 1121 and Super Basmati) and two non-Basmati cultivars (IR-64 and Pusa-44) were selected for this study. Among these varieties, Pusa 1121 and

Super Basmati were photosensitive, while the remaining three varieties were photo-insensitive. Length and breadth ratio as well as grain elongation in all Basmati rice was decrease due to increase in above mean temperature

20. AGRONOMY 14811

Agronomic Practices for Higher Production of Cotton Dr. Karmal Singh, Dr. A. K. Dhaka and Dr. Bhagat Singh

Department of Agronomy, CCS HAU Hisar *Corresponding Author eMail: [email protected]

The origins of cotton production and use go back to ancient times. The first evidence of cotton use was found in India and Pakistan, and dates from about 6,000 B.C. Scientists believe that cotton was first cultivated in the Indus delta. Today also Indian is the producer of cotton but the productivity of India is very low, similarly in India productivity of Northern region is very low as compare to Tamil Nadu. Farmers can increases their productivity of cotton crop by adopting better agronomic practices.

Cotton Field Preparation

Deep ploughing once in three years and two shallow ploughing every year are essential during summer. 1 - 2 deep ploughing once in three years is necessary to control deep-rooted weeds and to destroy the pest larvae or cocoons. Some farmers graze animals in summer. Green manuring is also an important way of maintaining soil fertility, but this can be adopted only under irrigated conditions or under cotton-legume crop rotation. Sowing of cotton should be avoided in sandy, saline or waterlogged soils. Cotton should be sown on well drained soils.

Plant Population and Geometry

Varieties Seed rate (kg/ha)

Spacing (cm)

Plant population (Per ha.)

American cotton

15-20 100x20

67.5x30 50000

49380 Desi cotton 10-12 67.5x30 49380

Hybrid 3-5 100x45

67.5x60

25000

24690

Bt Cotton 5 packets 100x45

67.5x60

25000

24690

Seed Treatment: Seed treatment is an important component for better crop production in any crop by doing seed treatment we can ensure the proper germination and also the initial better growth of the crop. Cotton seed should be treated with 10 ml of Chloropyriphos 20 EC in 10ml of water per kg of seed after that add 2 gm Bavistin per kg of seed, dry the seed in shade before sowing. Cotton seed should be sown 4-5 cm deep in the soil. Sowing of cotton from east to

west direction will give higher yield as compare to its sowing from north to south direction.

Sowing Time: Cotton is grown in Kharif season in the Haryana. Time of sowing spread over a period of April to first fortnight of June. However, in case of American cotton optimum time of sowing is May for better yields. Delay in sowing results in yield reduction. Desi cotton should be sown in first fortnight of April to escape early burning of plant in sandy soils.

Fertilizers: For obtaining high yield in cotton fertilizers should be applied on soil test basis. However for Haryana condition, 90: 30: 30 (Nitrogen, Phosphorus and Potassium respectively) kg ha is recommended for American Cotton and 50 kg Nitrogen for desi cotton. In case of hybrid cotton and Bt Cotton, 175: 60: 60 (Nitrogen, Phosphorus and Potassium respectively) kg/ha. Application of 10 kg/ha zinc sulphate is also recommended in all types of cotton. Full dose of Phosphorus, Potassium, and Zinc sulphate and 1/3rd part of nitrogen should be applied at the time of sowing of cotton. Second 1/3rd part of nitrogen fertilizer should be applied at the time of square formation and the remaining part of nitrogen should be applied at the time of flowering.

Irrigation: In cotton three or four irrigations are sufficient depending upon rainfall during the crop season. First irrigation in Cotton should be delayed as much we can so that better root development of the crop takes place. Moisture deficiency should not prevail during flowering and ball formation this situation will badly effect the seed cotton yield. Last irrigation should be applied when last 1/3rd of the bolls are opened after that no irrigation should be applied. To increase water productivity we can apply irrigation in cotton through bunds.

Weed Management: Cotton is a widely spaced crop hence weed problems are more in cotton. Weed management includes both chemical and mechanical weed control methods. One hoeing should be done before first irrigation with kasola after that after every irrigation hoeing is recommended till hoeing starts damaging the crop. Pre emergence application of 5 kg/ha of stomp is recommended in cotton.

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Picking: Picking of cotton should be does in such a way so that moisture in cotton should be less and it should be clean so that the quality of cotton remains good.

We must follow the recommended package for the control of disease ant insect pests of the region.

21. AGRONOMY 14833

Conservation Tillage: A Potential Solution to Reduce Soil Erosion

Shinde D. B.

Industrial Design Center, IIT Bombay, Powai, India.

INTRODUCTION: Since the dawn of cultivation, tillage has been one of the very important operation. It is the mechanical manipulation of soil with tools and implements for obtaining conditions ideal for seed germination, seedling establishment and growth of crops. Since the beginning of agriculture, tillage erosion is a problem that has been present. The problem has intensified with increased tillage speed, depth and size of tillage tools, and with the tillage of steeper and more undulating lands (Lindstrom M., 2002). This soil erosion and accompanying sedimentation in the downstream areas are continuing threat to the world’s land and water resources (Elsen et al., 2003; Flanagan, 2002; Govers et al., 1990; Hoyos, 2005; Navas et al., 2005; Pandey et al.,2009). By taking in to consideration the serious issue of soil erosion due to conventional tillage, the conservation tillage system has emerged.

Concepts of Conventional and Conservation Tillage

Conventional Tillage: Conventional tillage system includes seed bed preparation by using plough followed by other subsequent tillage operations. It varies widely among regions, has been defined by the Conservation Technology Information Center (CTIC 2002) as incorporating most crop residue and leaving less than 30 percent of the surface covered by residue after planting. Conventional tillage completely inverts the soil.

Conservation Tillage: Conservation tillage is any method of soil cultivation that leaves the previous year’s crop residue (such as corn stalks or wheat stubble) on fields before and after planting the next crop to reduce soil erosion and runoff, as well as other benefits such as carbon sequestration (MDA, 2011). With this technique, at least 30% of the soil surface is covered with crop residue/organic residue following planting (Dinnes, 2004). It also features non-inversion of the soil. This type of soil tillage is characterized by tillage depth and the percentage of surface area disturbed.

Types of Conservation Tillage Systems

1. Zero tillage 2. Strip tillage

3. Ridge tillage 4. Mulch tillage

Zero Tillage: It is defined as a system of planting (seeding) crops into untilled soil by opening a narrow slot trench or band only of sufficient width and depth to obtain proper seed coverage. No other soil tillage is done (Gattinger et al., 2011, MDA,2011). A typical zero-tillage machine is a heavy implement that can sow seed in slits 2-3cm wide and 4-7cm deep and apply fertilizer in one operation (CIMMYT, 2010).

Strip Tillage: Strip-tillage is a form of conservation tillage that clears crop residues in a narrow zone of soil and loosens subsoil layers prior to planting. This tillage zone is typically 8 to 12 inches wide and 2 to 14 inches deep, depending on the implement that is used.

Ridge Tillage: In ridge-tillage, the soil is also generally undisturbed from harvest to planting except for fertilizer injection.

Mulch Tillage: It includes any CT system other than no-tillage, strip tillage, or ridge-tillage that preserves 30 percent or more surface residues (MWFS 2000). The mulch is usually crop residue such as maize stover, sorghum trash and wheat straw. In cases where these are not available, or are eaten up by animals, gravel can be used as a mulch. (http://www.unep.or.jp/ietc/Publications/TechPublications/TechPub-8a/tillage.asp)

Advantages of Conservation Tillage over Conventional Tillage

1. The effect of residue cover on transmission losses is probably a key factor in explaining the erosion reducing effect of conservation tillage (Leys et al., 2010;Mazrei M., Ahangar G., 2013)

2. Labor saving: As land under conservation tillage is not cleared before planting it involves less weeding and pest problems.

3. Water saving: It requires significantly less water use due to increased infiltration and enhance water holding capacity from crop residues left on soil surface.

4. Increase in overall production: Conservation tillage results in increase in overall production as compared with convention tillage

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5. Other benefits include reduced soil compaction, utilization of marginal land, some harvesting advantages and conservation compliance.

Conclusion: To achieve sustainable food production with minimal impact on the soil and the atmosphere, conservation tillage practices become more important now than ever.

References CTIC (Conservation Technology Information Center).

2002. National crop residue management survey. West Lafayette, IN: CTIC.

Dinnes D.L. (2004): Assessment of practices to reduce Nitrogen and potassium non-point source pollution of Iowa’s surface waters, Iowa Dept. of National resources, Des Moines, LA.

Elsen E, et al. 2003. Discharge and sediment measurements at the outlet of a watershed on the Loess plateau of China. Catena. 54:147–160.

Flanagan D. 2002. Erosion encyclopedia of soil science. Marcel Dekker, New York: 395–398.

Andreas Gattinger A., Jawtusch J., Muller A., Mäder P.2011. CLIMATE CHANGE AND AGRICULTURE No-till agriculture – report no.2. Page no. 5

Govers G, et al. 1990. A long flume study of the dynamic factors affecting the resistance of a loamy soil to concentrated flow erosion. Earth

Surface Processes and Landforms 11: 515–524. Hoyos N.2005. Spatial modeling of soil erosion

potential in a tropical watershed of the Colombian Andes. Catena 63 (1): 85-108.

Leys A, et al. 2010. Scale effects on runoff and erosion losses from arable land under conservation and conventional tillage: The role of residue cover. J. of Hydrology 390: 143–154.

Lindstrom M., 2002. Tillage erosion, description and process of. Encyclopedia of soil science.1324-1326.

Mazrei M. and Ahangar G. 2013. The effects of tillage and geographic factors on soil erosion: A Review. IJACS. 6(14):1024-1031.

MDA (2011): Conservation Practices, Minnesota Conservation Funding Guide, Minnesota Department of Agriculture. Available at: http://www.mda.state.mn.us/protecting/conservation/practices/constillage...

Navas A, et al. 2005. Assessing soil erosion in a Pyrenean mountain catchment using GIS and fallout 137Cs. Agriculture, Ecosystems and Environment 105: 493-506.

Pandey A. 2009. Soil erosion modeling of a Himalayan watershed using RS and GIS. Environmental Earth Sciences 59 (2): 399-410.

Retrieved from http://www.climatetechwiki.org/technology/conservation-tillage (10/2/2017)

22. CROP ECOLOGY 14741

Major Air Pollutants and their Effect on Vegetation A. Daripa and S. Chattaraj

ICAR-National Bureau of Soil Survey and Land Use Planning, Nagpur- 440033

DEFINITION: Air pollution means any solid, liquid or gaseous substance present in ambient air in such concentrations that may tend to be injurious to human beings and other living creatures, plant, property or enjoyment (Indian air amendment act, 1987).

Classification of Air Pollutants

a) Primary pollutants- Pollutants are directly emitted from the source. For example- Sulfur dioxide (SO2) emission from thermal power plant. Nitric oxide (NO) and nitrogen dioxide (NO2) emission from automobiles.

b) Secondary pollutants- When primary pollutants are emitted from the source, they undergo various physical processes and chemical reactions in the atmosphere and form secondary pollutants. For Example: Ozone (O3), Acid rain (H2SO4, HNO3).

VOCs + NOx + Sunlight O3

SO2 + H2O vapour + O3 H2SO4

NOx + H2O vapour HNO3

Major Sources of Air Pollutants

a) Natural source- Pollutants emitted in the

atmosphere through natural source. For example- Dust from land with little or no vegetation, vegetation emits volatile organic carbons (VOCs) such as isoprene, smoke and carbon mono oxide (CO) from wildfires, volcanic activity- sulfur, chlorine and ash particulates.

b) Artificial source- Human factors are involved in causing the emission. For example- Oxides of nitrogen (NOx) emitted from a vehicle, burning of fossil fuels, incinerators, solid fuel for cooking and heating etc.

c) Stationary Source- The sources of pollutants are fixed in a place. For example- Thermal power plants, coal fired power plants.

d) Mobile source- The sources of pollutants are not fixed in a place and are mobile in nature. For example- Automobiles on highways, aircraft, farm vehicles, boats and ships.

Effect on Vegetation

The entry of air pollutants to plants may take place directly by gaseous diffusion or from the contaminated soil (acidic air pollutant in particular). The direct entry of gaseous air pollutants like SOx, NOx etc. may take place directly by stomata of the foliages. Solid

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particulates are adsorbed on the surface. The air pollution induced injury on various plant species are given in the following table-

TABLE 1: Visual effect of different air pollutants on vegetation

Sl No.

Pollutants Injury symptoms The sensitive age of leaf

Threshold ppm

1. SO2 Chlorosis, interveinal bleaching, tip and marginal necrosis similar to drought, insect and chilling injury

Middle aged most sensitive, older least sensitive

0.3

2. O3 Fleck, stiple, bleached and necrotic spotting, pigmentation

Oldest most sensitive, youngest least sensitive

0.03

3. PAN Glazing, silvering or browning of lower leaf surface

Youngest most sensitive

0.01

4. NO2 Irregular, white or brown collapsed lesions on leaf

Middle aged most sensitive

2.5

Role of Vegetation in Biomonitoring of Air Pollution

The concept of monitoring of air quality by plants is a well-established fact. The plants used for this purpose are termed indicator plants.

TABLE 2: Plants suitable for biomonitoring of air pollution in India.

Sl No.

Plants Air pollutants for which use suggested

1 Tobacco, grape and garden bean O3

2 White pine, moss and lichen SO2

3 Lettuce and bean PAN

4 Tomato and lettuce NOx

5 Orchids, cucumber and marigold C2H2

6 Apricot, peach and gladiolus HF

Sl No.

Plants Air pollutants for which use suggested

7 Moss and lichens SO2, particulates and heavy metals

The plants which are very sensitive to air pollutants are used as indicator species for biomonitoring of air quality. This method now appears to be a sensitive and low cost technique. The following table shows plants suitable for biomonitoring of air pollution in India.

Mitigation Measures for Combating Air Pollution

The atmosphere cleanses itself by dispersion, gravitational settling, flocculation, absorption, rain-washout, etc. However, source control of contaminants is more desirable for combating air pollution problem.

Source Control

Some measures that can be adopted in this direction are:

a) Using unleaded petrol b) Using fuels with low sulphur and ash content c) Encouraging people to use public transport,

walk or use a cycle as opposed to private vehicles

d) Plant trees along busy streets as they remove particulates, carbon dioxide and absorb noise

e) Industries and waste disposal sites should be situated outside the city preferably on the downwind of the city.

f) Catalytic converters should be used to help control emissions of carbon monoxide and hydrocarbons

Control Measures at Industrial Centers

a) Emission rates should be restricted to permissible levels by each and every industry

b) Incorporation of air pollution control equipment in design of plant layout must be made mandatory

c) Fuel switching- 30 to 90% reduction in emission of SO2.

23. CROP PHYSIOLOGY 13804

Screening of Plants for Abiotic Stress: Physiological and Biochemical Approaches

K. Suresh1, S. Sree Ganesh2, Manish B. Patil3 and K. Satish4 1M.Sc. (Plant Physiology), 3M.Sc. (Agril.) PBG, 4Ph.D. Scholar (PBG) Department of Genetics and Plant Breeding, C. P. College of Agriculture, S.D. Agricultural University, S.K. Nagar-385506, 2Ph.D. Scholar

(Plant Physiology), Navsari Agricultural University, Gujarat, India. *Corresponding Author eMail: [email protected]

INTRODUCTION: Plant growth, productivity, and distribution are greatly affected by environmental stresses such as drought, salinity and high

temperature. In response to abiotic stresses, plants undergo a variety of changes at the molecular level (gene expression) leading to physiological

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24. CROP PHYSIOLOGY 14644

Drought and Drought Management Strategies Aradhana Dhruw, Omesh Thakur and Vivek Kurrey

Ph.D. Scholar, IGKV Raipur (C.G.) *Corresponding Author eMail: [email protected]

INTRODUCTION: Low rainfall or failure of monsoon rain is a recurring feature in India. This has been responsible for droughts and famines. The word drought generally denotes scarcity of water in a region. Though, aridity and drought are due to insufficient water, aridity is a permanent climatic feature and is the culmination of a number of long term processes. However, drought is a temporary condition that occurs for a short period due to deficient precipitation for vegetation, river flow, water supply and human consumption. Drought is due to anomaly in atmospheric circulation.

Definition of Drought

a) American Meteorological Society defined drought as a period of abnormally dry weather sufficiently prolonged for lack of water to cause a severe hydrological imbalance in the area affected.

b) Prolonged deficiencies of soil moisture adversely affect crop growth indicating incidence of agricultural drought. It is the result of imbalance between soil moisture and evapo-transpiration needs of an area over a fairly long period so as to cause damage to standing crops and to reduce the yields.

Classification of Drought

Drought can be classified based on duration, nature of users, time of occurrence and using some specific terms.

1. Based on Duration

a) Permanent drought: This is characteristic of the desert climate where sparse vegetation growing is adapted to drought and agriculture is possible only by irrigation during entire crop season.

b) Seasonal drought: This is found in climates with well-defined rainy and dry seasons. Most of the arid and semiarid zones fall in this category. Duration of the crop varieties and planting dates should be such that the growing season should fall within rainy season.

c) Contingent drought: This involves an abnormal failure of rainfall. It may occur almost anywhere especially in most parts of humid or sub humid climates. It is usually brief, irregular and generally affects only a small area.

d) Invisible drought: This can occur even when there is frequent rain in an area.

When rainfall is inadequate to meet the evapo-transpiration losses, the result is borderline water deficiency in soil resulting in less than optimum yield. This occurs usually in humid regions.

2. Based on Relevance to the Users

a) Meteorological drought: It is defined as a condition, where the annual precipitation is less than the normal over an area for prolonged period (month, season or year).

b) Atmospheric drought: It is due to low air humidity, frequently accompanied by hot dry winds. It may occur even under conditions of adequate available soil moisture.

c) Hydrological drought: Meteorological drought, when prolonged results in hydrological drought with depletion of surface water and consequent drying of reservoirs, tanks etc.

d) Agricultural drought (soil drought): It is the result of soil moisture stress due to imbalance between available soil moisture and evapotranspiration of a crop. It is usually gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil moisture stress. This situation arises as a consequence of scanty precipitation or its uneven distribution both in space and time.

Important Causes for Agricultural Drought are

1. Inadequate precipitation 2. Erratic distribution 3. Lack of proper soil and crop management 4. Late onset of monsoon 5. Early withdrawal of monsoon 6. Long dry spells in the monsoon

C. Based on Time of Occurrence

a) Early season drought: It occurs due to delay in onset of monsoon or due to long dry spells after early sowing

b) Mid-season drought: Occurs due to long gaps between two successive rains and stored moisture becoming insufficient during the long dry spell.

c) Late season drought: Occurs due to early cessation of rainfall and crop water stress at maturity stage.

Other Terms to Describe Drought

a) Relative drought: The drought for one crop may not be a drought situation for another crop. This is due to mismatch between soil

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moisture condition and crop selection. b) Physiological drought: Refers to a condition

where crops are unable to absorb water from soil even when water is available, due to the high osmotic pressure of soil solution due to increased soil concentration, as in saline and alkaline soils. It is not due to deficit of water supply.

c) Periodicity of drought: The Indian Meteorological Department examined the incidence of drought for the period from 1871 to 1967, utilizing the monthly rainfall of 306 stations in the country. It was seen that during 1877, 1899, 1918 and 1972 more than 40 per cent of the total area experienced drought. General observation on the periodicity of drought in respect of different meteorological sub divisions of India is given below. Meteorological sub divisions Period of recurrence of drought Assam Very rare, once in 15 years West Bengal, MP, Konkan, Coastal AP, Kerala, Bihar, Orissa Once in 5 years South interior Karnataka, Eastern UP, Gujarat, Vidharbha, Rajasthan, Western UP, TN, Kashmir, Rayalaseema and Telangana. Once in 3 years. Western Rajasthan Once in 2.5 years

Effect of Drought on Crop Production

a) Water relations: Alters the water status by its influence on absorption, translocation and transpiration. The lag in absorption behind transpiration results in loss of turgor as a result of increase in the atmospheric dryness.

b) Photosynthesis: Photosynthesis is reduced by moisture stress due to reduction in Photosynthetic rate, chlorophyll content, leaf area and increase in assimilates saturation in leaves (due to lack of translocation).

c) Respiration: Increase with mild drought but more serve drought lowers water content and respiration.

d) Anatomical changes: Decrease in size of the cells and inter cellular spaces, thicker cell wall, greater development of mechanical tissue. Stomata per unit leaf tend to increase.

e) Metabolic reaction: All most all metabolic reactions are affected by water deficits.

f) Hormonal Relationships: The activity of growth promoting hormones like cytokinin, gibberellic acid and indole acetic acid decreases and growth regulating hormone like abscisic acid, ethylene, etc., increases.

g) Nutrition: The fixation, uptake and assimilation of nitrogen is affected. Since dry matter production is considerably reduced the uptake of NPK is reduced.

h) Growth and Development: Decrease in growth of leaves, stems and fruits. Maturity is delayed if drought occurs before flowering while it advances if drought occurs after flowering.

i) Reproduction and grain growth: Drought at grain development reduces yield while

vegetative and grain filling stages are less sensitive to moisture stress.

j) Yield: The effect on yield depends hugely on what proportion of the total dry matter is considered as useful material to be harvested. If it is aerial and underground parts, effect of drought is as sensitive as total growth.

Crop Adaptations

The ability of crop to grow satisfactorily under water stress is called drought adaptation. Adaptation is structural or functional modification in plants to survive and reproduce in a particular environment. Crops survive and grow under moisture stress conditions mainly by two ways:

1. Escaping Drought: Evading the period of drought is the simplest means of adaptation of plants to dry conditions. Many desert plants, the so called ephemerals, germinate at the beginning of the rainy season and have an extremely short life period (5 to 6 weeks) which is confined to the rainy period. These plants have no mechanism for overcoming moisture stress and are, therefore, not drought resistant. Germination inhibitors serve as safety mechanism. In cultivated crops, the ability of a cultivar to mature before the soil dries is the main adaptation to growth in dry regions. However, only very few crops have such a short growing season to be called as ephemerals.

2 Drought Resistance: Plants can adapt to drought either by avoiding stress or by tolerating stress due to different mechanisms. These mechanisms provide drought resistance.

Avoiding Stress

Stress avoidance is the ability to maintain a favourable water balance, and turgidity even when exposed to drought conditions, thereby avoiding stress and its consequences. A favourable water balance under drought conditions can be achieved either by: (i) conserving water by restricting transpiration before or as soon as stress is experienced; or (ii) accelerating water uptake sufficiently so as to replenish the lost water.

Strategies for Drought Management

The different strategies for drought management are discussed under the following heads.

1. Adjusting the plant population: The plant population should be lesser in dry land conditions than under irrigated conditions. The rectangular type of planting pattern should always be followed under dry land conditions. Under limited moisture supply the adjustment of plant population can be done by following method: a) Increasing the inter row distance: By

adjusting more number of plants within the row and increasing the distance between the rows reduces the competition during any part of the growing period of the crop. Hence it is more suitable for limited moisture supply conditions.

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b) Increasing the intra row distance: The distance between plants is increased by which plants grow luxuriantly from the beginning. There will be competition for moisture during the reproductive period of the crop.

2. Mid-season corrections: The contingent management practices done in the standing crop to overcome the unfavourable soil moisture conditions due to prolonged dry spells are known as mid-season conditions. a) Thinning: This can be done by removing

every alternate row or every third row which will save the crop from failure by reducing the competition.

b) Spraying: In crops like groundnut, castor, redgram, etc., during prolonged dry spells the crop can saved by spraying water at weekly intervals or 2 per cent urea at week to 10 days interval.

c) Ratooning: In crops like sorghum and bajra, ratooning can practiced as mid-

season correction measure after break of dry spell.

3. Mulching: It is a practice of spreading any covering material on soil surface to reduce evaporation losses. The mulches will prolong the moisture availability in the soil and save the crop during drought conditions.

4. Weed control: The water requirement of most of the weeds is more than the crop plants. Hence they compete more for soil moisture. Therefore the weed control especially during early stages of crop growth reduces the impact of dry spell by soil moisture conservation.

5. Water harvesting and lifesaving irrigation: The collection of runoff water during peak periods of rainfall and storing in different structures is known as water harvesting. The stored water can be used for giving the lifesaving irrigation during prolonged dry spells.

25. ORGANIC FARMING 14182

Biofertilizers: Types and their Applications 1Savita B. Ahire and 2Mohitpasha S. Shaikh

1Agriculture Assistant in Taluka Agriculture Office Sakri, Taluka – Sakri, Dist – Dhule, 424304. (M.S.) 2Assistant Field Officer in Soil and Land Use Survey of India, Bishnavghata Patuli Township, Block-E,

Kolkata- 700 094. (W.B.)

INTRODUCTION: 'Biofertilizer' is a substance which contains living microorganism which, when applied to seed, plant surfaces, or soil, colonizes the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers are not fertilizers. Fertilizers directly increase soil fertility by adding nutrients. Biofertilizers add nutrients through the natural processes of fixing atmospheric nitrogen, solubilizing Phosphorus, and stimulating plant growth through the synthesis of growth promoting substances. They can be grouped in different ways based on their nature and function.

S. No.

Groups Examples

N2 fixing Biofertilizers

1. Free-living Azotobacter, Clostridium, Anabaena, Nostoc,

2. Symbiotic Rhizobium, Frankia, Anabaena azollae

3. Associative Symbiotic

Azospirillum

P Solubilizing Biofertilizers

1. Bacteria Bacillus megaterium var. phosphaticum

Bacillus circulans, Pseudomonas striata

S. No.

Groups Examples

2. Fungi Penicillium sp, Aspergillus awamori

P Mobilizing Biofertilizers

1. Arbuscular mycorrhiza

Glomus sp., Gigaspora sp., Acaulospora sp.,

Scutellospora sp. & Sclerocystis sp.

2. Ectomycorrhiza Laccaria sp., Pisolithus sp., Boletus sp., Amanita sp.

3. Orchid mycorrhiza Rhizoctonia solani

Biofertilizers for Micro nutrients

1. Silicate and Zinc solubilizers

Bacillus sp.

Plant Growth Promoting Rhizobacteria

1. Pseudomonas Pseudomonas fluorescence

Different Types of Biofertilizers

1. Rhizobium - This belongs to bacterial group and the classical example is symbiotic nitrogen fixation. The bacteria infect the legume root and form root nodules within which they reduce molecular nitrogen to ammonia which is reality utilized by the plant to produce valuable proteins, vitamins and other nitrogen containing compounds. The site of symbiosis is within the root nodules. It

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has been estimated that 40-250 kg N / ha / year is fixed by different legume crops by the microbial activities of rhizobium.

2. Azotobacter - It is the important and well known free living nitrogen fixing aerobic bacterium. It is used as a Bio-Fertilizer for all non-leguminous plants especially rice, cotton, vegetables etc. Azotobacter cells are not present on the rhizoplane but are abundant in the rhizosphere region. The lack of organic matter in the soil is a limiting factor for the proliferation of Azotobacter in the soil.

3. Azospirillum- It belongs to bacteria and is known to fix the considerable quantity of nitrogen in the range of 20- 40 kg N/ha in the rhizosphere in non- non-leguminous plants such as cereals, millets, Oilseeds, cotton etc.

4. Cyanobacteria- A group of one-celled to many-celled aquatic organisms. Also known as blue-green algae.

5. Azolla- Azolla is a free-floating water fern that floats in water and fixes atmospheric nitrogen in association with nitrogen fixing blue green algae anabaena azolla. Azolla fronds consist of saprophyte with a floating rhizome and small overlapping bi-lobed leaves and roots. Azolla is considered to be a potential biofertilizer in terms of nitrogen contribution to rice. Long before its cultivation as a green manure, Azolla has been used as a fodder for domesticated animals such as pigs and ducks. In recent days, Azolla is very much used as a sustainable feed substitute for livestock especially dairy cattle, poultry, piggery and fish

6. Phosphate solubilizing microorganisms (PSM) 7. AM fungi- An arbuscular mycorrhiza (AM

Fungi) is a type of mycorrhiza in which the fungus penetrates the cortical cells of the roots of a vascular plant.

8. Silicate solubilizing bacteria (SSB) - Microorganisms are capable of degrading

silicates and aluminum silicates. During the metabolism of microbes several organic acids are produced and these have a dual role in silicate weathering.

9. Plant Growth Promoting Rhizobacteria (PGPR)-The group of bacteria that colonize roots or rhizosphere soil and beneficial to crops are referred to as plant growth promoting rhizobacteria (PGPR).

Application of Biofertilizers

1. Seed treatment 2. Seedling root dip 3. Main field application

Seed Treatment: One packet of the inoculant is mixed with 200 ml of rice kanji to make slurry. The seeds required for an acre are mixed in the slurry so as to have a uniform coating of the inoculant over the seeds and then shade dried for 30 minutes. The shade dried seeds should be sown within 24 hours. One packet of the inoculant (200 g) is sufficient to treat 10 kg of seeds.

Seedling Root Dip: This method is used for transplanted crops. Two packets of the inoculant are mixed in 40 litres of water. The root portion of the seedlings required for an acre is dipped in the mixture for 5 to 10 minutes and then transplanted.

Main Field Application: Four packets of the inoculant is mixed with 20 kgs of dried and powdered farm yard manure and then broadcasted in one acre of main field just before transplanting.

Rhizobium: - For all legumes Rhizobium is applied as seed inoculant.

Rhizobium (only seed application is recommended)

Azospirillum/Azotobacter: In the transplanted crops, Azospirillum is inoculated through seed, seedling root dip and soil application methods. For direct sown crops, Azospirillum is applied through seed treatment and soil application.

26. ORGANIC FARMING 14538

Organic Agriculture: It’s Importance in Crop Cultivation L. Netajit Singh1, Elangbam Bidyarani Devi2, Elangbam Premabati Devi3 and Deepshikha4

1Ph.D. Scholar, Department of Agricultural Statistics, Navsari Agricultural University, Gujarat 2Ph.D. Scholar, Department of Entomology, Assam Agricultural University, Jorhat, Assam

3Assistant Research Scientist, Plant Pathology, Wheat Research Station, SDAU, Gujarat 4J.R.O., Department of Plant Pathology, G.B.P.U.A.T., Pantnagar, Uttarakhand

INTRODUCTION: Increasing consciousness about conservation of environment as well as health hazards associated with agrochemicals and consumers’ preference to safe and hazard-free food are the major factors that lead to the growing interest in alternate forms of agriculture in the world. Organic agriculture is one among the broad spectrum of production methods that are supportive of the environment. The demand for

organic food is steadily increasing both in the developed and developing countries with an annual average growth rate of 20-25%. Organic farming system in India is not new and is being followed from ancient time. It is a method of farming system which primarily aimed at cultivating land and raising crops in such a way, to keep the soil alive and in good health by the use of organic wastes (crop, animal and farm wastes,

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aquatic weeds) and other biological materials along with beneficial microbes (biofertilizers) to release nutrients to crops for increased sustainable production in an eco-friendly pollution free environment. It was introduced by Sir Albert Howard, recognized as “Father of Organic Farming”.

The Codex Alimentarius Commission defines “Organic agriculture as a holistic food production management system, which promotes and enhances agro-ecosystem health including biodiversity, biological cycles and soil biological activity. It emphasizes the use of management practices in preference to the use of off-farm inputs, taking into account that regional conditions require locally adapted systems. This is accomplished by using, where possible, agronomic, biological and mechanical methods, as opposed to using synthetic materials, to fulfill any specific function within the system”.

Needs of Organic Farming

With the increase in population our compulsion would not only stabilize agricultural production but to increase in sustainable manner. The Green Revolution and its chemical based technology are losing its appeal as dividends are failing and returns are unsustainable. Pollution and climate change are other negative externalities caused by use of fossil fuel based chemicals. Thus, a natural balance needs to be maintained at all costs for existence of life and poverty.

1. Organic Food Industry is Growing Fast and Guarantees High Profitability: Current market trends reveals that organically produce products are becoming widely accepted throughout the world. Over the past few years, the annual sales of organic products have increased three fold with increase establishment of natural food stores selling varieties of organic products. The farmers market also offers commercialization of regionally and locally produced organic products. Accordingly, the retail rates of organic products are expected to continue rising in the coming years at a rate more than 20% yearly.

2. Environmental Sustainability and Food Security: Attaining a friendly and green environment has always been a great concern worldwide and research discloses that organic farming can partly form a solution. Long term studies bout organic agricultural practice it can provide an impressive mechanism for promoting ecological harmony, biodiversity and biological cycles which are vital for environmental sustainability. The definitive objectives of organic farming are founded on soil management and conservation, promoting nutrient cycle, ecological balance and conserving biodiversity. On this basis, the practices

marvelously aid in building the capacity to mitigate the impacts of global climate change and contributing to environmental preservation. In addition to reversing global climate change impacts, organic agriculture can trim down emissions from fossil fuels mainly due to the use of cover crops and grass clovers in organic rotations. Organic farming also saves up energy since its production methods are energy efficient compared to the conventional methods, thereby lessening depletion of natural resources used for generating energy. Besides a recent study stressed that promotion of organic farming can intensify yield production particularly in poor countries where inputs for conventional agriculture are highly expensive, thus contributing to increased food security.

3. Improvement of Human Health: Organic produce offer the safest products for human consumption than any other available products. They contain lower levels of chemicals and do not contain modified ingredients compared to the conventional agricultural produce. Organic standards set strict regulations to ensure final products for consumption are free from synthetic chemical components and genetically modified production technologies, or any other perceived natural toxins. As such, organic farm produce improves human health by ensuring risks to disease conditions like cancer, infertility and immuno deficiency are minimized.

The key features of organic farming includes:

1. Protecting soil quality using organic material and encouraging biological activity.

2. Indirect provision of crop nutrients using soil microorganisms.

3. Nitrogen fixation in soils through the use of legumes.

4. Weed, disease and pest control based on methods like crop rotation, biological diversity, natural predators, organic manures and suitable chemical, thermal and biological intervention.

5. Rearing of livestock, taking care of housing, nutrition, health, rearing and breeding.

6. Care for larger environment and conservation of natural habitats and wild life.

Principles of Organic Farming

1. Principle of Health: Organic agriculture must contribute to the health and wealth being of soils, plants, animals, humans and the earth. It is the sustenance of mental, physical, ecological and social well-being. For instance, it provides pollution and chemical free, nutritious food items for humans.

2. Principle of Fairness: Fairness is evident in maintaining equity and justice of the shared planet both among humans and other living

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beings. Organic farming provides good quality of life and helps in reducing poverty. Natural resources must be judiciously used and preserved for future generations.

3. Principles of Ecological Balance: Organic farming must be modeled on living ecological systems. Organic farming methods must fit the ecological balances and cycles in nature.

4. Principle of Care: Organic agriculture should be practiced in a careful and responsible manner to benefit the present and future generations and the environments.

Types of Organic Farming

There are different types of organic farming system which are mentioned below:

1. Eco Farming: Farming in relation to ecosystem. It aims at the maintenance of soil chemically, biologically and physically the way nature would left it alone. Feed the soil, not the plant is the watchword and slogan of ecological farming.

2. Biological Farming: Farming in relation to biological diversity.

3. Biodynamic farming: It was developed by Rudolf Steiner. This method emphasizes the use of manures and composts and excludes the use of artificial chemicals on soil and plants. It treats soil fertility, plant growth, and livestock care as ecologically interrelated tasks.

4. Do nothing or Natural farming: This farming is a closed system, in which system demands no inputs and imitates nature. This farming have refined into five ideologies that are no use tillage, fertilizer, pesticides, weeding and

pruning.

Organic farming is a welcome alternative for farmers, it is less financial draining for the environment which will be less taxing to ecosystem and would help to improve soil fertility. Quality of agricultural produce improves by organic manures than excessive use of fertilizers because components of organic farming are able to supply about all the growth principles besides all the essential plant nutrients. Organic farming system employs management practices which seek to nurture ecosystems which achieve sustainable productivity and provide weed, pest and disease control through a diverse mixture of mutually dependent life forms, recycling plant and animal residues, crop selection and rotation, water management, tillage and cultivation. Soil fertility is maintained and enhanced by a system which optimizes soil biological activity and the physical and mineral nature of the soil as a means to provide a balanced nutrient supply for plant and animal life as well as to conserve soil resources. Production should be sustainable with the recycling of plant nutrients as an essential part of the fertilizing strategy. Pest and disease management is attained by means of the encouragement of a balanced host/predator relationship, augmentation of beneficial insect populations, biological and cultural control and mechanical removal of pests and affected plant parts. It is believed by many that organic farming is much healthier and sustainable potion. Although the health benefits of organic food are yet to be proven fully, consumers are willing to pay a higher premium for organic crops.

27. SUSTAINABLE AGRICULTURE 14196

Bioplastic from Corn Starch N. Vairam

Assistant Professor, Department of Plant Breeding & Genetics, Imayam Institute of Agriculture and Technology, Thuraiyur, Trichy-621 206.

INTRODUCTION: Bioplastics are a form of plastics derived from renewable biomass sources, such as vegetable fats and oils, corn starch, pea starch or micobiota. Some bioplastics look virtually indistinguishable from traditional petrochemical plastics. Polylactide acid (PLA) looks and behaves like polyethylene and polypropylene and is now widely used for food containers. Unlike traditional plastics and biodegradable plastics, bioplastics generally do not produce a net increase in carbon dioxide gas when they break down (because the plants that were used to make them absorbed the same amount of carbon dioxide to begin with). Another good thing about bioplastics is that they're compostable: they decay into natural materials that blend harmlessly with soil. Some bioplastics

can break down in a matter of weeks. The cornstarch molecules they contain slowly absorb water and swell up, causing them to break apart into small fragments that bacteria can digest more readily.

Bioplastic Properties

Moisture resistant, water insoluable, optically pure, impermeable to oxygen

Maintain stability during manufacture and use but degrade rapidly when disposed of or recycled

Degrades at 1850C

Properties may be manipulated by blending polymers or genetic modifications.

Some are rubbery and moldable. Some are stiff and brittle.

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Poly (lactic acid) (PLA) resins are well-known biodegradable, linear aliphatic thermoplastics, which can be produced from renewable resources (PLA and PLA blends generally come in the form of granulates with various properties, and are used in the plastic processing industry for the production of films, fibers, plastic containers, cups and bottles (Warvel et al. 2001). PLA, for example, produces almost 70 percent less greenhouse gases when it degrades in landfills.

A Recipe for PLA Bioplastics

1. Take some corn kernels (lots of them). 2. Process and mill them to extract the dextrose

(a type of sugar) from their starch. 3. Use fermenting vats to turn the dextrose into

lactic acid. 4. In a chemical plant, convert the lactic acid

into lactide. 5. Polymerize the lactide to make long-chain

molecules of polylactide acid (PLA).

Applications/Uses of Bio-Plastics

Applications of Bio-plastics include single-use items such as plates, utensils, cups, and film wrap plastic bottling and as paper coatings by fast-food companies, clothing fibers compost bags, in the biomedical field, etc.

Advantages of Bio-Plastics

1. Reduced CO2 emissions: One metric ton of bioplastics generates between 0.8 and 3.2 fewer metric tons of carbon dioxide than one metric ton of petroleum-based plastics.

2. Cheaper alternative: Bio-plastics are becoming more viable with volatility in oil prices

3. Waste: Bio-plastics reduce the amount of toxic runoff generated by the oil-based alternatives.

4. Benefit to rural economy: Prices of crops, such as maize, have risen sharply in the wake of global interest in the production of bio-fuels

and bio-plastics, as countries across the world look for alternatives to oil to safeguard the environment and for attaining energy security.

5. Reduced carbon footprint: Oil based plastics require fossil fuel as a key raw material. In addition, oil based plastics like PP and PS require more energy during the plastic development process when compared with bioplastics. A Life Cycle Analysis for a typical PP or PS plastics shows a carbon footprint of approx 2.0 kg CO2 equivalents per kg of plastic (from cradle to factory gate). These CO2 emissions are 4 times higher than the CO2emissions for Poly Lactic Acid (PLA) resin.

6. Multiple end-of-life options: valuable raw materials can be reclaimed and recycled into new products, reducing the need for new virgin material and negative environmental impact of 'used' plastic products can be greatly reduced, if not, eliminated.

Disadvantages of Bio-Plastics

1. Biodegradable plastic is not meant to be recycled with other types of plastics.

2. If biodegradable plastic are not properly disposed of, it leads to an inefficient breakdown of the plastic, which can release toxins (carbondioxide, methane etc) into the environment.

Conclusion: Environmental, economic, and safety challenges have provoked many scientists to partially substitute petrochemical-based polymers with biodegradable one’s i.e. Bio-plastics. Bio degradable polymers may not be a one stop solution to all environmental problems created by plastics but it’s a step in the right direction as time is of essence for biodegradable polymer development as society’s current views on environmental responsibility make this an ideal time for further growth of biopolymers.

References Laxmana Reddy, R., V. Sanjeevani Reddy and G.

Anusha Gupta. 2013. Study of Bio-plastics As Green & Sustainable Alternative to Plastics. Int. J. Emer. Tech. and Adv. Engg., 3(5): 82-89.

Warwel, S., F. Brüse, C. Demes, M. Kunz and M. Rüsch gen Klaas. 2001. Polymers and surfactants on the basis of renewable resources. Chemosphere., 43: 39–48.


Neem –The Bitter Gem N. Vairam

Assistant Professor, Department of Plant Breeding & Genetics, Imayam Institute of Agriculture and Technology, Thuraiyur, Trichy-621 206.

INTRODUCTION: The Neem tree, known in botanical terms as Azadirachta indica derives its

name from Azad meaning free, Dirakht denoting a tree, iHind means of Indian origin. Hence, Neem

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and contains many plant nutrients, viz., nitrogen 2-3%, phosphorus 1% and potassium 1.4%. It also contains 1.0-1.5% tannic acid and has the highest sulphur content of 1.07 – 1.36% among the oil cakes. The neem cake contains a large number of triterpenoids, more of which are being discovered.

Conclusion: Role of Neem in Agriculture is remarkable as growth regulators, fertilizer, compost, manure, soil conditioner, insecticide and biocontrol agent etc., It is used in several ways in

the improvement of crop yield. Farmers, understanding the potentiality of neem, still in practice of using various neem products as part of organic farming and indigenous traditional knowledge. The Government should spread the awareness of neem usage to safeguard the soil and environment in an ecofriendly manner. Mass plantation of neem trees should be encouraged among school students which would serve the purpose.


Sustainable Agriculture: A Key Way to Manage Land Degradation

Dinesh Kumar1*, Anil Kumar Mawalia2 and Vikas Vishnu3 1M.Sc. (Agri.) and 2,3Ph.D., Department of Agronomy,

Navsari Agricultural University, Navsari, Gujarat-396450 *Corresponding Author eMail: [email protected]

INTRODUCTION: With the increasing population pressure, total and per capita demand for grain will increase continuously. A doubling in global food demand projected for the next 50 years poses huge challenges for the sustainability both of food production and of terrestrial & aquatic ecosystem and the services they provide to society. India is primarily based upon agriculture and most of the Indian population is engaged in agriculture. Land is the primary input and factor of production which is not consumed but without which no production is possible. It is the resource that has no cost of production. Although, its usage can be switched from a less to more profitable one, its supply cannot be increased. The term 'land' includes all physical elements in the wealth of a nation bestowed by nature; such as climate, environment, fields, forests etc. Agricultural land is typically land devoted to agriculture, the systematic and controlled use of other forms of life - particularly the rearing of livestock and production of crops - to produce food for human.

Land degradation is a global issue of the 21st century and by the year 2050 it may create a serious threat to food production, adverse impact on agronomic productivity, the environmental pollution, food security and quality of life. Hence a proper planning and management of the available land resource is necessary to ensure maintenance of their production potential, quality and diversity. Integrated land management practices such as organic farming and agronomical activities would be the key to enhancing land productivity on a sustainable basis.

What is Sustainable Agriculture?

Sustainable agriculture is the “efficient production of safe, high quality agricultural products, in a way that protects and improves the natural environment, the social and economic conditions

of farmers, their employees and local communities, and safeguards the health and welfare of all farmed species”.

What is Land Degradation?

Land degradation is the temporary or permanent lowering of the productive capacity of land. It thus covers the various forms of soil degradation, adverse human impacts on water resources, deforestation, and lowering of the productive capacity of rangelands.

Causes of Degradation

Type of degradation

Percentage area of degradation type caused by

Defores-tation

Over-grazing

Agricultural activities

Overcutting of

vegetation

Water erosion 61 67 2 44

Wind erosion 21 46 1 98

Soil fertility decline

25 0 75 0

Salinization 34 30 14 87

Waterlogging 0 0 85 33

Lowering of water table

12 22 65 34

All types of degradation

37 46 15 63

Components of Land Degradation

Loss of biodiversity

Salinization

Water erosion

Sand dune enrichment

Rangeland degradation

Outmigration

Management of Land Degradation through Sustainable Agriculture: Sustainable Land

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Management (SLM) can be defined as “the use of land resources, including soils, water, animals and plants, for the production of goods to meet changing human needs, while simultaneously ensuring the long-term productive potential of these resources and the maintenance of their environmental functions”. There are many land conservation best management practices that have been developed over the years. Some of these practices are being mentioned below.

Tillage: Most common tillage practices used to reduce land degradation are strip tillage, ridge tillage and no-till.

Grassed waterway: Here grasses are planted in a depression going across the field where, run off mostly is captured from this field. Therefore slowing down of runoff and thus prevent or minimize erosion.

Nutrient management: Nutrient management is the process of maintaining and/or enhancing soil fertility, and it is done through the use of the nutrients already in the soil or adding nutrients through organic fertilizers (application of compost). The purpose of nutrient management is to increase soil and crop productivity, and increase climate resilience. The most common practices are use of green manure, cover crops, animal manure, mulching, liquid manure, compost, mineral fertilizers and agricultural lime.

Soil and water conservation: This technique include terraces, contour bunds, broad beds

and furrows, semi-circular bunds, trash lines, diversion ditches and cut-off drains, retention ditches, pitting, trenches, tied ridges, grass strips and irrigation.

Restoration and rehabilitation: Natural regeneration is the deliberate re-establishment of healthy vegetation and biomass on degraded land by accelerating or enhancing the way the vegetation naturally changes (ecological succession).

Agroforestry: Agroforestry is the deliberate growing of woody perennials (trees, shrubs) as agricultural crops alongside other crops and/or livestock in the same land. It improves productivity and mitigates the impacts of climate change (adaptation and mitigation). Agroforestry has three major attributes: productivity, sustainability and adoptability.

Conservation agriculture and residue management: Conservation agriculture is the way in which crops can be grown in a sustainable way while conserving the environment. Residue management refers to the sound handling and utilization of plant and crop residues that combines mulching, composting, integrative manure and livestock management.

Conclusion: Sustainable agriculture practices not only minimize/prevent the land degradation but also conserve environment. It increases crop as well as land productivity on a long term sustainable basis.


Remediation of Heavy Metals for Sustainable Crop Production

Subhaprada Dash1*and D. Sethi2

1Department of Agronomy, Palli Siksha Bhavana (Institute of Agriculture), Visva-Bharati, Sriniketan – 731236. West Bengal, 2Department of Soil Science and Agricultural chemistry, O.U.A.T., Odisha


INTRODUCTION: Over the past years the problems of toxic heavy metals have risen tremendously in various crop fields. Uptake and accumulation by crop plants represents the main entry pathway for potentially health-threatening toxic metals into human and animal food. The pollution of the ecosystem by heavy metals is a real threat to the environment because metals cannot be degraded like organic pollutants and persist in the ecosystem having accumulated in different parts of the food chain. Heavy metals become toxic when they are not metabolized by the body and accumulate in the soft tissues. Agricultural soils in many parts of the world are slightly too moderately contaminated by heavy metal toxicity such as Cd, Cu, Zn, Ni, Co, Cr, Pb, and As. This could be due to long term use of phosphatic fertilizers, sewage sludge application,

dust from smelters, industrial waste and bad watering practices in agricultural lands. The heavy metals accumulating in soil may get entry into the human and animal food chain through the crops like leafy vegetables and tuber crops which are grown on it.

Bio Remediation

To remediate these, sustainable and inexpensive process is emerging as a viable alternative. On heavy metal removal aspects, there are four methods for removing hazardous heavy metal such as chemical/physical remediation, animal remediation, phyto remediation and micro remediation. Now a days the focus area is based on the latter two, namely the use of plants and microbes, which are preferred because of their cost-effectiveness, environmental friendliness and

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fewer side effects. The researchers are also trying to focus on the application of genetic engineering or cell engineering to create an expected and ideal species against heavy metal stress.

The procedure involves selection of suitable crops for bioremediation of contaminated site like castor which removes more quantity of total heavy metals (Cd+Ni+Cr+Co+Pb) from contaminated soil in one cropping season, development of new bioremediation strategies with the inoculation of heavy metal resistant bacteria like Pseudomonas sp., Proteus sp. and Klebsellia sp. to enhance biological-extraction of metals from contaminated soils and could increase the growth of Oryza sativain contaminated field and lastly to generate transgenic plants using several different genes regulating glutathione levels in plants. These remediations are depending on the factors like availability of time and economic importance of the crop.

Role of Glutathione in Heavy Metal Stress Tolerance of Plants

Glutathione, a tri-peptide is most abundant low molecular weight thiol in all mitochondria-bearing eukaryotes including plants. In plants, glutathion is involved in sequestration of heavy metals. Glutathione exists in two form reduced glutathione (GSH) and oxidized glutathione (GSSG). The reduction potential of glutathione depends on the intracellular GSH/GSSG ratio. Change in the redox ratio of glutathione mainly depends on the pH, total GSH concentration, GSH biosynthesis and GSH catabolism (Mullineaux and Rausch, 2005). Several studies indicate that γ-glutamylcysteine synthetase is a major regulatory enzyme in glutathione biosynthesis. The chemical reactivity along with the relative stability and high water solubility of GSH makes it an ideal biochemical to protect plants against heavy metals stresses (Rausch et al., 2007).

Through genetic manipulation of glutathione-related synthesis genes in plants, tolerance to various heavy metals has been studied. Genes such as γ-glutamylcysteine synthetase (GSH1), glutathione synthetase (GSH2), cystathionine synthase (CTS), ATP sulfurylase (APS), serine acetyltransferase (SAT), glutathione reductase (GR), phytochelatin synthase (PCS) and

glyoxalases (glyoxalaseI and II) have been found to be potential candidate for providing heavy metal stress tolerance by regulating GSH levels. Over expression of these enzymatic genes in various plants has contributed to higher tolerance and accumulation of heavy metals.

The Escherichia coli GSH2 gene encoding glutathione synthetase was over expressed in the cytosol of Indian mustard (B. juncea L.). The transgenic plants accumulated significantly more Cd than the wild-type and showed enhanced tolerance to Cd at both seedling and mature plant stages. Cd accumulation and tolerance were correlated with the GSH2 expression level.

Transgenic tobacco (N. tabacum cv. LA Burley 21) lines expressing three genes encoding enzymes out of which GSH1, involved in the production of a GSH precursor γ-EC. These transgenics were analyzed for non-protein thiols content and Cd accumulation. Plants expressing these transgenes have increased Cd concentration in roots (Wawrzyński et al., 2006), suggesting their role in heavy metal stress tolerance in plants.

The suitable crop needs to be selected for bioremediation of contaminated site depending on the factors like availability of time and economic importance of the crop. The mechanism of heavy metal tolerance in plants has strongly suggested that glutathione should not be limiting. Therefore, attempts have been made to generate transgenic plants using several different genes regulating glutathione levels in plants.

References Mullineaux, P., Rausch, T., 2005. Glutathione,

photosynthesis and the redox regulation of stress-responsive gene expression. Photosynthesis Research 86, 459–474.

Wawrzyński, A., Kopera, E., Wawrzyńska, A., Kamińska, J., Bal, W., Sirko, A., 2006. Effects of simultaneous expression of heterologous genes involved in phytochelatin biosynthesis on thiol content and cadmium accumulation in tobacco plants. Journal of Experimental Botany 57, 2173–2182.

Rausch, T., Gromes, R., Liedschulte, V., Muller, I., Bogs, J., Galovic, V., Wachter, A., 2007. Novel insight into the regulation of GSH biosynthesis in higher plants. Plant Biology (Stuttgart) 9, 565–572.


Biochar: Tool to Mitigate Climate Change with Sustainable Crop Production

P. N. Patle and S. A. Durgude

M.Sc. Student, Department of Soil Science and Agril. Chemistry, M.P.K.V., Rahuri (M.S.) *Corresponding Author eMail: [email protected]; [email protected]

INTRODUCTION: An increasing number of global perils such as climate change, declining

agricultural production, scarcity of water, fertilizer shortage, poverty and the resulting environmental

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and social disruption seems formidable. The exigency to address these menace generates escalating demand for solutions that can be implemented with paramount aim of sustainability of agro ecosystem and mitigate climate change altogether. Recent research findings globally pertaining to above issues highlighted potential of “Biochar” in meticulous way. So this text is intended to grab rudimentary facts, properties and credibility of “Biochar”.

What is biochar?: The term “Biochar” is a relatively recent development, emerging in conjunction with soil management and C sequestration concern, yet it is not new to mankind. Soils throughout the globe contain biochar deposited through natural events, like forest and grassland fires, landslide etc. Biochar is the product of high temperature treatment of carbonaceous materials with little or no oxygen present, the treatment termed as “pyrolysis”. Biochar is a carbon rich, fine grained, highly porous, predominantly stable organic carbon compound. It is produced by Thermal decomposition of biomass (e.g., agricultural crop residues, wood, waste, etc.) In oxygen depleted environment.

Specific properties of biochar: While raw organic materials supply nutrients to plants and soil microorganisms, biochar serves as a catalyst that enhances plant uptake of nutrients and water. Compared to other soil amendments, the high surface area and porosity of biochar enable it to adsorb or retain nutrients and water and also provide a site for beneficial microorganism to carry out various nutrient transformations.

(Ultramicroscopic image of biochar showing porous internal structure)

Benefits to environment: Biochar can be a simple yet powerful tool to combat climate change. Biochar can be produced from waste

biomass using modern novel technologies which are economically feasible. As organic materials decay, burning of residues in agricultural fields generates greenhouse gases, such as CO2 and CH4 (where CH4 having 21 times more potential act as a greenhouse gas than CO2), are released into the atmosphere. By charring the organic material, much of the carbon becomes “fixed” into a more stable form, and when the resulting biochar is applied to soils, the carbon is effectively sequestered into the soil for interminable time.

(source:-www.biochar-international.org)

The application of biochar to soil is proposed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Literature suggested that biochar have potential to reduce current global carbon emission at least by 10% which can play a great role in counterattacking climate change which is result of increased carbon emission in environment indeed.

Future avenues: Bichar gaining worldwide attention for its positive potential in agriculture sector. So research on economical techniques for production of biochar is matter of thrust in Indian context as country has abundance of raw material and agriculture land which should be dealt in sustainable approach. Also encouragement for research in this area by government agency would certainly add future affirmative assets for future generations.

32. WATER MANAGEMENT 14206

Salt Stress: Causes and Management Dr. A. Suganya

Research Associate, Water Technology Centre, Tamil Nadu Agricultural University, Coimbatore -03.

Salinity is a major factor affects crop growth and productivity at global level. Salt stress in plants is developed due to excess salt in the soil, which reduces the water potential of the soil and making

the soil solution unavailable to the plants. This effect is termed as physiological drought. According to the estimates, about one third of the irrigated land on the earth is affected by salt

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Introduction to Hydrological Model Dileshwari1, Mansingh Banjare2

Department of Soil and Water Engineering1, Department of Farm Machinery and Power Engineering2, IGKV Raipur, Chhattisgarh


Hydrology is the study of the movement, distribution, and quality of water on Earth. It encompasses both the hydrologic cycle and water resources. The discipline of hydrology includes the fields of hydrometeorology, surface hydrology, hydrogeology, drainage basin management, and water quality. Hydrologists can be found working in earth or environmental science, physical geography, geology, or civil and environmental engineering. They may be engaged in activities such as hydraulic modeling, flood mapping, catchment flood management plans, shoreline management plans, estuarine strategies, coastal protection, and flood alleviation.

Hydrologic models are simplified, conceptual representations of a part of the hydrologic cycle. They are primarily used for hydrologic prediction and for understanding hydrologic processes.

Two major types of hydrologic models can be distinguished:

Stochastic Models - These models are black box systems, based on data and using mathematical and statistical concepts to link a certain input (for instance rainfall) to the model output (for instance runoff). Commonly used techniques are regression, transfer functions, neural networks and system identification. These models are known as stochastic hydrology models.

Process-Based Models - These models try to represent the physical processes observed in the real world. Typically, such models contain representations of surface runoff, subsurface flow, evapotranspiration, and channel flow, but they can be far more complicated. These models are known as deterministic hydrology models. Deterministic hydrology models can be subdivided into single-event models and continuous simulation models.

These days hydrologic modelling has play important role to the understanding of the behaviour of hydrologic systems in an attempt to make better predictions and to address the major challenges in water resources management.

Hydrological models may also be classified based on the particular aspect of the hydrological cycle which they address. Two of these more specialized models are:

1. Groundwater models. These are computer models of groundwater flow systems, and are used by hydrogeologists.

Groundwater models are employed to simulate and predict aquifer conditions. Groundwater models need: a) hydrological inputs - rainfall,

evapotranspiration and surface runoff, which determine the recharge; these inputs may vary both from time to time and from place to place

b) operational inputs - inputs which concern human interferences with the water management like irrigation, drainage, pumping from wells, watertable control, and the operation of retention or infiltration basins; these inputs may also vary in time and space

c) External conditions - initial and boundary conditions. Boundary conditions can be related to levels of the water table, artesian pressures, and hydraulic head along the boundaries of the model on the one hand (the head conditions), or to groundwater inflows and outflows along the boundaries of the model on the other hand (the flow conditions). The may also include quality aspects of the water like salinity. The initial conditions refer to initial values of elements that may increase or decrease in the course of the time within the model. The initial and boundary conditions may vary from place to place. The boundary conditions may be kept either constant or be made variable in time.

d) hydraulic parameters - topography, thicknesses of soil layers and their horizontal/vertical hydraulic conductivity (permeability to water), aquifer transmissivity and resistance, aquifer porosity and storage coefficient, as well as the capillarity of the unsaturated zone.

2. Groundwater models may also have chemical components like water salinity, soil salinity and other quality indicators of water and soil, for which inputs may be needed. a) Surface water models. These are

computer models used to understand surface water systems and potential changes due to natural or anthropogenic influences.

b) Runoff models are mathematical models describing the rainfall - runoff relations of a rainfall catchment area, drainage basin

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or watershed. More precisely, they produces a surface runoff hydrograph as a response to a rainfall hydrograph input. In other words, these models calculate the conversion of rainfall into runoff.

c) Hydrological transport models are mathematical models used to simulate river or stream flow and calculate water quality parameters.

Hydrological Modelling Software

Variety of programs developed for hydrological modelling. Several examples are:

1. Hydrologic Engineering Center's River Analysis System - [HEC-RAS]. HEC-RAS is a computer program that models the hydraulics of water flow through natural rivers and other channels. The program is one-dimensional, meaning that there is no direct modeling of the hydraulic effect of cross section shape changes, bends, and other two- and three-dimensional aspects of flow. The program was developed to manage the rivers, harbors, and other public works. This model is an example of a process-based, surface water model. Specifically, it is a hydrological transport model.

2. Arc Hydro Tools and Data Model - Arc Hydro is a data model and toolset for integrating geospatial and temporal water resource information that can be run within ESRI's ArcGIS geographic information system. Thus, Arc Hydro supports hydrologic and hydraulic analysis within a GIS application. Although implemented in a commercial GIS environment, the data model and toolset are in the public domain and available free of charge. Arc Hydro is used to define the watersheds, stream networks, channels, structures, measurement stations, and land surface properties that cover the study region.

3. MODFLOW, PMWIN, and MODFLOW Toolbox - MODFLOW is the U.S. Geological Survey's modular finite-difference flow model, which is a computer code that solves the groundwater flow equation. The program is used by hydrogeologists to simulate the flow of groundwater through aquifers. MODFLOW is a process-based groundwater model. PMWIN (Processing Modflow for Windows) is a non-commercial GUI (graphical user interface) for MODFLOW processing and visualization. To help to integrate the arc hydro data model with MODFLOW, a set of geoprocessing tools, the MODFLOW Toolbox, were developed to link the data model structure to the model. The toolbox includes a set of tools to create the feature needed for storing input and outputs of MODFLOW model and to help users view the modeling result within ArcGIS.

Hydrological modelling systems are work

based on these two processes:

Data Preparation

Creates trend or constant surfaces to represent head, thickness, porosity etc.

Creates well feature dataset storing well locations, pumping rate and transmissivity for computing drawdown.

Creates particle feature dataset storing particle locations for particle tracking. A group of particles are automatically created around a pumping well.

Reverses (flip) the direction of the Darcy Flow output direction raster for backward tracking.

Analysis

Computes drawdown for a single or multiple pumping wells.

Creates residual, direction and magnitude using the Darcy Flow method.

Performs particle tracking for a single or multiple particles using Particle Track method. In the case of multiple particles, the paths are appended in a single feature dataset.

Creates concentration distribution of a pollutant using Porous Puff method.

Determines capture zone of a pumping well.

Application of Hydrological Model

1. To prediction of Soil moisture and effective precipitation

2. To prediction Evapotranspiration 3. To prediction Runoff response 4. To prediction of sediment load, and 5. To prediction of drought.

All these parameter are predicted based on past data, which are used as input data in hydrological model.

List of Hydrological Model

Agricultural Policy/Environmental eXtender (APEX), Geomorphology-Based Hydrological Model (GBHM), Hydrologic Modeling System (HEC-HMS), Hydrologic Simulation Model (HSIMHYD), Integrated Hydro Meteorological Model (IHMM), Water Quality/Solute Transport (OTIS), Soil Water Assessment Tool (SWAT), Large Scale Catchment Model, formerly CALSIM (WRIM), Global Hydrologic Evaluation Model (GHEM), Regional Hydro-climate Model (Reg-HCM)

Conclusions: Recent advances in hydrologic numerical simulation models offer unprecedented opportunities for improving existing engineering hydrology curricula. Such models provide teaching tools that can serve two main purposes:

1. It’s help in understanding complex and multi-faceted concepts and processes.

2. Equip them with practical skills that are critically needed for their future prediction of hydrology and related fields.

3. Based on future prediction identify problem, developed solution and try to implement

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solution in the field.


Drastic Model: Tools to Identified Groundwater Vulnerability Dileshwari1, Mansingh Banjare2 and Omesh Thakur3

Research Scholar Department of Soil and Water Engineering1, Department of Farm Machinery and Power Engineering2, Department of Vegetable Science3, IGKV Raipur, Chhattisgarh


Introduction: The groundwater is major source of water for a wide range of beneficial uses, being the most significant freshwater resource on the planet Earth. All human activities can negatively impact water quality in aquifers, these impacts can result in the temporary or permanent loss of the resource, significant costs to remediate the aquifer and /or to remove the harmful materials from the water prior to use. The aquifers vulnerability at one moment represent a problem of both industrial but also of developing countries, where industry or agriculture grow fast at the same time with the urbanization process.

DRASTIC is a method developed by the Environmental Protection Agency (EPA) to provide a systematic evaluation of the potential for groundwater contamination that is consistent on a national basis. The DRASTIC parameters are the hydro geologic parameters which affect water transport from the soil surface to the aquifer. The DRASTIC parameters are weighted and then summed to come up with a vulnerability rating or DRASTIC index. DRASTIC assumes that all contaminants move with the water and are introduced at the soil surface. Although it is easy to identify examples in which this assumption is false, DRASTIC provides a tool for relative vulnerability assessment.

Drastic Parameters

D- Depth to Water R- Net Recharge A- Aquifer Media S- Soils T- Topography I- Impact of Vadose Zone C- Hydraulic Conductivity

From these parameters a DRASTIC index or vulnerability rating can be obtained. The higher the value for the DRASTIC index, the greater the vulnerability of that location of an aquifer.

Drastic Index = DrDw + RrRw + ArAw + SrSw

+ TrTw + IrIw + CrCw

Where, w = weight; r = rank

D-Depth to Water: Depth to Water affects the time available for a contaminant to undergo chemical and biological reactions such as dispersion, oxidation, natural attenuation, sorption etc. A low depth to water parameter will lead to a higher vulnerability rating. Depth to

water can be estimated based on well log data from the USGS or the Texas Water Development Board.

R-Net Recharge: Net Recharge is the amount of water which enters the aquifer. This value can be calculated on an annual or monthly basis with data available. Although recharge will dilute the contaminant which enters the aquifer, recharge is also the largest pathway for contaminant transport. Therefore, the amount of recharge is positively correlated with the vulnerability rating.

Net Recharge can be calculated using climate data by applying a mass balance on the water.

Net Recharge = Precipitation+ Evaporation+ Runoff

A-Aquifer Media: Aquifer Media is used to produce a rating based on the permeability of each layer of media. High permeability allows more water and therefore more contaminants to enter the aquifer. Therefore a high permeability will yield a high vulnerability rating. Some aquifer media data can be found in well logs from USGS and the TWDB. However, this data is not routinely collected and therefore is not reliable.

S-Soil Media: Soil media is affects the transport of the contaminant and water from the soil surface to the aquifer. Some of the interactions with soil have already been stated, but for review, the soil media can affect the types of reactions which can take place. Sorption phenomena, for example, can be affected by the structure of the soil surface. Additionally, different soils will provide better habitats for microorganisms which can potentially biodegrade the contaminant. The rating system that is proposed by Aller et. al. follows. This rating system seems to be based on the hydrological transport of the contaminant to the aquifer, rather than on other characteristics. Soils data is available for STATSGO for entire states and SSURGO for particular counties. Unfortunately the available date is difficult to interpret such that the above ratings could be applied. With some assistance, the STATSGO data could be classified into the above categories.

T-Topography: The topography of the land affects groundwater vulnerability because the slope of the land is in important factor in determining whether the contaminant released will become run-off or infiltrate the aquifer. With

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a low slope, the contaminant is less likely to become run-off and therefore more likely to infiltrate the aquifer. Digital Elevation Data (DEM) may be used to calculate and project the slope using GIS.

I-Impact of Vadose Zone: The vadose zone is the typical soil horizon above and below the water table, which is unsaturated or discontinuously saturated. If the vadose zone is highly permeable then this will lead to a high vulnerability rating. Information regarding the vadose zone is not readily available.

C-Hydraulic Conductivity: The hydraulic conductivity relates the factures, bedding planes and intergranular voids in the aquifer. These components become pathways for fluid movement, and likewise pathways for contaminant movement once a contaminant enters

the aquifer. The hydraulic conductivity is positively correlated with the vulnerability rating. The USGS has grid data of the hydraulic conductivity available for select aquifers. For example I have access to the Ogallala aquifer. Using a GIS, each of the DRASTIC parameters could be graphically represented. By converting all of the files to grid documents, the RASTER calculator could then be used to produce a vulnerability map. An example of a vulnerability map is below.

Applications: DRASTIC can be used to model groundwater vulnerability. The DRASTIC method is very simple and effective way of characterizing groundwater vulnerability to contamination. GIS can help make the results of a complicated model more clearly through visual representation, thus providing an applicable tool for decision makers.

36. SOIL SCIENCE AND AGRICULTURAL CHEMISTRY 14007

Management of Nitrogen Fertilizers in Soils A. G. Durgude and S. R. Kadam

Department of Soil Science and Agril. Chemistry, Mahatma Phule Krishi Vidyapeeth, Rahuri

Nitrogen fertilizers may causes few problem when added to soil like loss of nitrogen (volatilization, Denitrification, leaching, Decomposition crop removal and soil erosion), toxicity and acidity. In general nitrogen use efficiency ranged from 40 to 50%. For increase in nitrogen use efficiency in soil, the following tips of management aspects are very important.

1. Immediately after application (within a few hours), urea must be incorporated with soil by tillage or washed into the soil. Urea should never left on the soil surface without incorporation.

2. In coarse textured soil (sandy or sandy loam soil), urea may be applied on the surface followed by controlled irrigation, so that urea is washed into the soil with percolating water.

3. Avoid broadcasting of urea in highly alkaline and highly calcareous soil to control volatilization losses. So deep incorporation of urea should be made.

4. Split application of nitrogenous fertilizers should be adopted.

5. Slow release nitrogen fertilizer may be used to avoid volatilization leaching and denitrification and loss of nitrogen.

E.g.

1. Coated urea eg. sulphur coated urea 2. Uncoated urea eg. CDU (crotonylidene

diurea) a) IBDU (Isobutyraldehyde diurea) b) Acetaldehyde (Urea Z)

3. Other sparingly soluble N fertilizer: USG (urea supergranules)

4. Nitrification inhibitors: -

a) Synthetic inhibitors i) 2 Chloro -6 (trichloromethyl),

pyridine or Nitropyrin or N-serve. ii) Potassium azide iii) DCD (dicyn adiamide) iv) AM (2-amino-4-chloro-6-methyl

pyridins v) DCS (N 2,6-dichlorophenyl

succnamide b) Non synthetic Inhibitor: Neem cake,

Mahua cake, Karanj cake c) Ureas inhibitors – Hydroxamic acid,

Thioures, Acetohedroxamate Methyl urea, Thiocorbamate, Quinones i) Anhydrous ammonia (NH3) or aqua

ammonia (NH4OH) may be applied in rice field before submerging or puddling to avoid denitrification.

ii) Under leached or high rainfall condition acid soil, use of ammonical (ammonium sulphate) fertilizer should be recommended instead of nitrate fertilizer.

iii) Urea: DAP (60:40 ratio) briquette application is recommended @170 kgha-1 to lowland rice

iv) Urea, ammonium sulphate or diammonium phosphate should be placed at least 2.5 to 3cm below the seed and 5to 7 cm away from seed.

v) Avoid prolonged use of nitrogen fertilizer, particularly ammonium sulphate or ammonium sulphate nitrate at high rate causes a loss of calcium in surface soil and acidifies the soil.

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vi) Field must be free from weeds and control the surface erosion which causes N loss.

vii) Use calcium ammonium nitrate fertilizer to no calcareous soils and red or laterites soil.

viii) Improve acid soil by applying lime as per pH of soil and in strongly alkaline soil, gypsum application as per the gypsum requirement of soil which

will increase the nitrogen use efficiency.

ix) As per deficiency of nitrogen (yellowing of leaves) foliar spray of urea 1 to 2 % is recommended at early growth stages of crops.

x) Use of urea, ammonium sulphate through drip (fertigation) for different vegetable and fruit crops, increase the nitrogen use efficiency.


Role of Potassium in Plants Dr. A. Suganya

Research Associate, Water Technology Centre, Tamil Nadu Agricultural University, Coimbatore -03.

Potassium (K) is one of the essential nutrients in plants and in recent years is one of three (including nitrogen and phosphorus) that are commonly in sufficiently short supply in the soil to limit crop yields on many soil types. Potassium is commonly found in plants at levels above all other macro nutrients except carbon, oxygen, hydrogen and occasionally nitrogen. Potassium has many functions including the regulation of the opening and closing of stomata which are the breathing holes found on plant leaves and therefore regulate moisture loss from the plant. For this reason potassium is known as poor-man’s irrigation because it helps crops finish better.

Potassium Deficiency

Most heavy soils contain adequate amounts of naturally occurring potassium for optimum crop and pasture growth. Sandy soils in higher rainfall areas are prone to potassium deficiency, as both native and fertiliser applied potassium is held poorly and is subject to leaching.

Deficiency in Legumes

Pasture legumes are particularly susceptible to, and can be affected by, potassium deficiency when cereal yields remain unaffected.

Visual Symptoms: Potassium is highly mobile in the phloem and can be moved to newer leaves if the nutrient is in short supply, with deficiency symptoms appearing first on older leaves. General symptoms initially include a light green to yellow

colour of the older leaves. Marginal scorch of the edges and tips of these leaves follows, often resulting in senescence. As the severity increases, this condition progresses towards the top of the plant. These characteristic symptoms of potassium deficiency can often be mistaken for leaf diseases such as yellow spot and Septoria nodorum blotch in wheat or brown leaf spot. Other symptoms include slow plant growth, weak stems and lodging, high screenings levels in the harvested grain and reduced disease resistance.

Fertiliser Placement and Timing

Banded potassium has been shown to be twice as accessible to the crop as top-dressed potassium. This is thought to be related to improved availability for the emerging crop, and decreased availability for weeds. Growers should not band high rates (i.e. >15 kg/ha) particularly with sensitive crops and should try to place potassium fertilisers away from the seed.

Fertiliser Types and Recommendation: Muriate of potash (MOP-KCl; 49.5 % K) is the cheapest form of potassium and is applied by top dressing either before seeding or up 5 weeks after seeding. Sowing MOP directly with the seed can significantly reduce crop germination and establishment. The development of sulphate of potash (SOP) is a less damaging form of potassium and can be drilled with seed. This product is significantly more expensive than MOP per unit of potassium.


Soil Respiration Reshma B. Sale1, S. R. Tatpurkar2 and Ruenna M. D’souza3

Senior Research Fellow1, NRM Section, ICAR-CCARI, Goa, Senior Research Assistant 2, Department of Soil Science and Agricultural Chemistry, MPKV Rahuri, Project Assistant3, NRM Section, ICAR-CCARI,

Goa-403402.

Concept of Soil Respiration: Carbon dioxide (CO2) release from the soil surface is referred to as soil

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respiration. This CO2 results from several sources, including aerobic microbial decomposition of soil organic matter (SOM) to obtain energy for their growth and functioning (microbial respiration), plant root and faunal respiration, and eventually from the dissolution of carbonates in soil solution. Soil respiration is one measure of biological activity and decomposition. The rate of CO2 release is expressed as CO2-C lbs/acre/day (or kg/ha/d). It can be measured by simple field methods or more sophisticated field and laboratory methods. During the decomposition of SOM, organic nutrients contained in organic matter (e.g., organic phosphorus, nitrogen, and sulphur) are converted to inorganic forms that are available for plant uptake. This conversion is known as mineralization. Soil respiration is also known as carbon mineralization.

Importance of Soil Respiration

Soil respiration reflects the capacity of soil to support soil life including crops, soil animals, and microorganisms. It describes the level of microbial activity, SOM content and its decomposition.

In the laboratory, soil respiration can be used to estimate soil microbial biomass and make some inference about nutrient cycling in the soil.

Soil respiration also provides an indication of the soil's ability to sustain plant growth.

Excessive respiration and SOM decomposition usually occurs after tillage due to destruction of soil aggregates that previously protected SOM and increased soil aeration.

Depleted SOM, reduced soil aggregation, and limited nutrient availability for plants and microorganisms can result in reduced crop production in the absence of additional inputs.

The threshold between accumulation and loss of organic matter is difficult to predict without knowledge of the amount of carbon added.

Problems that might be caused by Poor Function

Reduced soil respiration rates indicate that there is little or no SOM or aerobic microbial activity in the soil.

It may also signify that soil properties that contribute to soil respiration (soil temperature, moisture, aeration, available N) are limiting biological activity and SOM decomposition.

With reduced soil respiration, nutrients are not released from SOM to feed plants and soil organisms. This affects plant root respiration, which can result in the death of the plants.

Incomplete mineralization of SOM often occurs in saturated or flooded soils, resulting in the formation of compounds that are harmful to plant roots, (e.g. methane and alcohol).

In such anaerobic environments, denitrification and sulphur volatilization usually occur, contributing to greenhouse gas emissions and acid deposition.

How to improve Soil Respiration: The rate of soil respiration under favourable temperature and moisture conditions is generally limited by the supply of SOM. Agricultural practices that increase SOM usually enhance soil respiration.

The following practices have the potential to significantly improve SOM and indirectly soil respiration when other factors are at an optimum:

Conservation tillage (no-till, strip-till, mulch till, etc.)

Application of manure and other organic by-products

Rotations with high residue and deep-rooted crops

Cover and green manure crops

Irrigation or drainage


Phosphorus: Its importance, Dynamics and Fate in Soils Dheeraj Panghaal and Chetan Kumar Jangir

Ph.D. Scholars Department of Soil Science CCS Haryana Agricultural University, Hisar 125004.

Phosphorus (P) is an essential plant macronutrient as relatively large amounts of P required by plants. Phosphorus is among the three nutrients generally applied to the soils. Phosphorus availability in soils is limited due to its precipitation with calcium or iron.

Phosphorus is taken up by plants from soils, utilized by animals that consume plants, and returned to soils as organic residues decay in soils. When plant materials are returned to the soil, this organic phosphate will slowly be released as inorganic phosphate or be incorporated into more

stable organic materials and become part of the soil organic matter. The release of inorganic phosphate from organic phosphates is called mineralization and is done by microorganisms breaking down organic compounds. The microorganism activity is highly influenced by soil temperature and moisture. The mineralization is most rapid when soils are warm and moist but well drained. Phosphate can be lost through soil erosion and water running over or through the soil.

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Important Roles of Phosphorus in Plants

Phosphorus is an essential nutrient both as a part of several key plant structure compounds and as a catalysis in the conversion of numerous key biochemical reactions in plants. Phosphorus is known especially for its role in capturing and converting the sun's energy into useful plant compounds.

It is a vital component of DNA, the genetic "memory unit" of all living things. It is also a component of RNA. Phosphorus bonds links the structures of both DNA and RNA. Phosphorus is a vital component of ATP, the "energy currency" of plants. Thus, phosphorus is vital for the general health and vigor of all plants. Some specific growth factors that have been associated with phosphorus are:

Stimulates root growth and development

Increases stalk and stem strength

Improvement in formation of flower and seed production

Crop maturity is more uniform and early

Increased nitrogen N-fixing capacity of legume crops

Enhancement in quality of crops

Increased resistance to plant diseases

Supports development throughout entire life cycle

Dynamics of Phosphorus in Soils

In soils P exists in many different forms. In practical terms, however, P in soils can be thought of existing in 3 "pools" also called dynamics of phosphorus as:

Solution P

Active P

Fixed P

The solution P pool is very small and will usually contain only a fraction of a pound of P per acre. The solution P will generally be in the orthophosphate form, but small amounts of organic P may exist as well. Plants take up P in the orthophosphate form only. The solution P pool is important because it is the pool from which plants take up P and is the only pool that has any measurable mobility. Most of the P taken up by a crop during a growing season will moves only an inch or less through the soil to the roots. A growing crop would quickly deplete the P in the soluble P pool if the pool was not being continuously replenished.

The active P pool is Phosphorus in the solid phase which is relatively easily released to the soil solution, the water surrounding soil particles. As plants take up phosphate, the concentration of phosphate in solution is decreased and some phosphate from the active P pool is released. Because the solution P pool is very small, the active P pool is the main source of available P for crops. The ability of the active P pool to replenish the soil solution P pool in a soil is what makes a

soil fertile with respect to phosphate. An acre of land may contain several pounds to a few hundred pounds of P in the active P pool. The active P pool will contain inorganic phosphate that is attached (or adsorbed) to small particles in the soil, phosphate that reacted with elements such as calcium or aluminum to form somewhat soluble solids, and organic P that is easily mineralized. Adsorbed phosphate ions are held on active sites on the surfaces of soil particles. The amount of phosphate adsorbed by soil increases as the amount of phosphate in solution increases and vice versa. Soil particles can act either as a source or a sink of phosphate to the surrounding water depending on conditions. Soil particles with low levels of adsorbed P that are eroded into a body of water with relatively high levels of dissolved phosphate may adsorb phosphate from the water, and vice versa.

The fixed P pool of phosphate will contain inorganic phosphate compounds that are very insoluble and organic compounds that are resistant to mineralization by microorganisms in the soil. Phosphate in this pool may remain in soils for years without being made available to plants and may have very little impact on the fertility of a soil. The inorganic phosphate compounds in this fixed P pool are more crystalline in their structure and less soluble than those compounds considered to be in the active P pool. Some slow conversion between the fixed P pool and the active P pool does occur in soils.

Fate of Phosphorus Added to the Soils

The phosphorus in fertilizers and manure is initially quite soluble and available. Manure have soluble, organic and inorganic phosphate compounds that are quite available. As the fertilizer or manure phosphate comes in contact with the soil, various reactions begin occurring that make the phosphate less soluble and less available. The rates and products of these reactions are dependent on such soil conditions as pH, moisture content, temperature, and the minerals already present in the soil.

FIGURE 1: Relationship of Phosphorus availability with soil pH

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Dissolving of the fertilizers increase the soluble phosphate in the soil solution around the particle and allows the dissolved phosphate to move a short distance away from the fertilizer particle. Movement is slow but may be increased by rainfall or irrigation water flowing through the soil. As phosphate ions in solution slowly migrate away from the fertilizer particle, most of the phosphate will react with the minerals within the soil. Phosphate ions generally react by adsorbing to soil particles or by combining with elements in the soil such as calcium (Ca), magnesium (Mg), aluminum (Al), and iron (Fe), and forming compounds that are solids. The adsorbed phosphate and the newly formed solids are relatively available to meet crop needs.

Gradually reactions occur in which the adsorbed phosphate and the easily dissolved compounds of phosphate form more insoluble compounds that cause the phosphate to be become fixed and unavailable. Over time this results in a decrease in soil test P. The mechanisms for the changes in phosphate are complex and involve a variety of compounds. In alkaline soils (soil pH greater than 7) Ca is the dominant cation (positive ion) that will react with phosphate. A general sequence of reactions in alkaline soils is the formation of dibasic calcium phosphate dihydrate, octocalcium phosphate, and hydroxyapatite. The formation of each product

results in a decrease in solubility and availability of phosphate. In acidic soils (especially with soil pH less than 5.5) Al is the dominant ion that will react with phosphate. In these soils the first products formed would be amorphous Al and Fe phosphates, as well as some Ca phosphates. The amorphous Al and Fe phosphates gradually change into compounds that resemble crystalline variscite (an Al phosphate) and strengite (an Fe phosphate). Each of these reactions will result in very insoluble compounds of phosphate that are generally not available to plants. Reactions that reduce P availability occur in all ranges of soil pH but can be very pronounced in alkaline soils (pH > 7.3) and in acidic soils (pH < 5.5). Maintaining soil pH between 6 and 7 will generally result in the most efficient use of phosphate.

Adding to the active P pool through fertilization will also increase the amount of fixed P. Depleting the active pool through crop uptake may cause some of the fixed P to slowly become active P. The conversion of available P to fixed P is partially the reason for the low efficiency of P fertilizers. Most of the P fertilizer applied to the soil will not be utilized by the crop in the first season. Continued application of more P than the crops utilize increases the fertility of the soil, but much of the added P becomes fixed and unavailable.


Drought and Drought Management Strategies Dr. Archana Rajput

Senior Research Fellow, Department of Soil Physics, Indian Institute of Soil Science, Bhopal, MP *Corresponding Author eMail: [email protected]

Drought: It is the result of imbalance between soil moisture and evapotranspiration needs of an area over a fairly long period as to cause damage to standing crops and to reduce the yields. The irrigation commission of India defines drought as a situation occurring in any area where the annual rainfall is less than 75% of normal rainfall.

Classification of drought: Drought can be classified based on duration, nature of users, time of occurrence and using some specific terms.

1. Based on duration a) Permanent drought: This is characteristic

of the desert climate where sparse vegetation growing is adapted to drought and agriculture is possible only by irrigation during entire crop season.

b) Seasonal drought: This is found in climates with well-defined rainy and dry seasons. Most of the arid and semiarid zones fall in this category. Duration of the crop varieties and planting dates should be such that the growing season should

fall within rainy season. c) Contingent drought: This involves an

abnormal failure of rainfall. It may occur almost anywhere especially in most parts of humid or sub humid climates. It is usually brief, irregular and generally affects only a small area.

d) Invisible drought: This can occur even when there is frequent rain in an area. When rainfall is inadequate to meet the evapo-transpiration losses, the result is borderline water deficiency in soil resulting in less than optimum yield. This occurs usually in humid regions.

2. Based on relevance to the users (National Commission on Agriculture,1976) a) Meteorological drought: It is defined as a

condition, where the annual precipitation is less than the normal over an area for prolonged period (month, season or year).

b) Atmospheric drought: It is due to low air humidity, frequently accompanied by hot dry winds. It may occur even under

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conditions of adequate available soil moisture. It refers to a condition when plants show wilting symptoms during the hot part of the day when transpiration exceeds absorption temporarily for a short period. When absorption keeps pace with transpiration the plants revive. (Mid-day wilt).

c) Hydrological drought: Meteorological drought, when prolonged results in hydrological drought with depletion of surface water and consequent drying of reservoirs, tanks etc. It results in deficiency of water for all sectors using water. This is based on water balance and how it affects irrigation as a whole for bringing crops to maturity.

d) Agricultural drought (soil drought): It is the result of soil moisture stress due to imbalance between available soil moisture and evapotranspiration of a crop. It is usually gradual and progressive. Plants can therefore, adjust at least partly, to the increased soil moisture stress. This situation arises as a consequence of scanty precipitation or its uneven distribution both in space and time. Relevant definition of agricultural drought appears to be a period of dryness during the crop season, sufficiently prolonged to adversely affect the yield. The extent of yield loss depends on the crop growth stage and the degree of stress. It does not begin when the rain ceases, but actually commences only when the plant roots are not able to obtain the soil moisture rapidly enough to replace evapotranspiration losses.

3. Based on time of occurrence a) Early season drought: It occurs due to

delay in onset of monsoon or due to long dry spells after early sowing

b) Mid-season drought: Occurs due to long gaps between two successive rains and stored moisture becoming insufficient during the long dry spell.

c) Late season drought: Occurs due to early cessation of rainfall and crop water stress at maturity stage.

Other Terms to Describe Drought

1. Relative drought: The drought for one crop may not be a drought situation for another crop. This is due to mismatch between soil moisture condition and crop selection. For Eg. A condition may be a drought situation for growing rice, but the same situation may not be a drought for growing groundnut.

2. Physiological drought: Refers to a condition where crops are unable to absorb water from soil even when water is available, due to the high osmotic pressure of soil solution due to increased soil concentration, as in saline and

alkaline soils. It is not due to deficit of water supply.

Important causes for agricultural drought are: (1) Inadequate precipitation (2) Erratic distribution (3) Long dry spells in the monsoon (4) Late onset of monsoon. (5) Early withdrawal of monsoon (6) Lack of proper soil and crop management

Effect of Drought on Crop Production

1. Water relations: Alters the water status by its influence on absorption, translocation and transpiration. The lag in absorption behind transpiration results in loss of turgor as a result of increase in the atmospheric dryness.

2. Photosynthesis: Photosynthesis is reduced by moisture stress due to reduction in Photosynthetic rate, chlorophyll content, leaf area and increase in assimilates saturation in leaves (due to lack of translocation).

3. Respiration: Increase with mild drought but more serve drought lowers water content and respiration.

4. Anatomical changes: Decrease in size of the cells and inter cellular spaces, thicker cell wall, greater development of mechanical tissue. Stomata per unit leaf tend to increase.

5. Metabolic reaction: All most all metabolic reactions are affected by water deficits.

6. Hormonal Relationships: The activity of growth promoting hormones like cytokinin, gibberellic acid and indole acetic acid decreases and growth regulating hormone like abscisic acid, ethylene, etc., increases.

7. Nutrition: The fixation, uptake and assimilation of nitrogen is affected. Since dry matter production is considerably reduced the uptake of NPK is reduced.

8. Growth and Development: Decrease in growth of leaves, stems and fruits. Maturity is delayed if drought occurs before flowering while it advances if drought occurs after flowering.

9. Reproduction and grain growth: Drought at flowering and grain development determines the number of fruits and individual grain weight, respectively. Panicle initiation in cereals is critical while drought at anthesis may lead to drying of pollen. Drought at grain development reduces yield while vegetative and grain filling stages are less sensitive to moisture stress.

10. Yield: The effect on yield depends hugely on what proportion of the total dry matter is considered as useful material to be harvested. If it is aerial and underground parts, effect of drought is as sensitive as total growth. When the yield consists of seeds as in cereals, moisture stress at flowering is detrimental. When the yield is fibre or chemicals where economic product is a small fraction of total dry matter moderate stress on growth does not have adverse effect on yields.

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Crop Adaptations: The ability of crop to grow satisfactorily under water stress is called drought adaptation. Adaptation is structural or functional modification in plants to survive and reproduce in a particular environment. Crops survive and grow under moisture stress conditions mainly by two ways: (i) Escaping drought and (ii) Drought resistance (Fig. 1)

1. Escaping Drought: Evading the period of drought is the simplest means of adaptation of plants to dry conditions. Many desert plants, the so called ephemerals, germinate at the beginning of the rainy season and have an extremely short life period (5 to 6 weeks) which is confined to the rainy period. These plants have no mechanism for overcoming moisture stress and are, therefore, not

drought resistant. Germination inhibitors serve as safety mechanism. In cultivated crops, the ability of a cultivar to mature before the soil dries is the main adaptation to growth in dry regions. However, only very few crops have such a short growing season to be called as ephemerals. Certain varieties of pearl millet mature within 60 days after sowing. Short duration pulses like cowpea, greengram, blackgram can be included in this category. In addition to earliness, they need drought resistance because there may be dry spells within the crop period of 60 days. The disadvantage about breeding early varieties is that yield is reduced with reduction in duration.

FIG. 1: Flow chart showing different mechanisms for overcoming moisture stress

2. Drought Resistance: Plants can adopt to drought either by avoiding stress or by tolerating stress due to different mechanisms. These mechanisms provide drought resistance. a) Avoiding Stress: Stress avoidance is the

ability to maintain a favourable water balance, and turgidity even when exposed to drought conditions, thereby avoiding stress and its consequences. A favourable water balance under drought conditions can be achieved either by: (1) conserving water by restricting transpiration before or as soon as stress is experienced. (2) Accelerating water uptake sufficiently so as to replenish the lost water.

Strategies for drought management: The different strategies for drought management are discussed under the following heads.

Adjusting the plant population: The plant population should be lesser in dryland conditions than under irrigated conditions. The rectangular type of planting pattern should always be followed under dryland conditions.

Mid-season corrections: The contingent management practices done in the standing crop to overcome the unfavourable soil moisture conditions due to prolonged dry spells are known as mid-season conditions.

– Thinning: This ca be done by removing every alternate row or every third row which will save the crop from failure by reducing the competition

– Spraying: In crops like groundnut, castor, redgram, etc., during prolonged dry spells the crop can saved by spraying water at weekly intervals or 2 per cent urea at week to 10 days interval.

– Ratooning: In crops like sorghum and bajra, ratooning can practiced as mid-season correction measure after break of dry spell.

Mulching: It is a practice of spreading any covering material on soil surface to reduce evaporation losses. The mulches will prolong the moisture availability in the soil and save the crop during drought conditions.

Weed control: Weeds compete with crop for different growth resources ore seriously under dryland conditions. The water requirement of most of the weeds is more than the crop plants. Hence they compete more for soil moisture. Therefore the weed control especially during early stages of crop growth reduces the impact of dry spell by soil moisture conservation.

Water harvesting and lifesaving irrigation: The collection of runoff water during peak periods of rainfall and storing in different structures is known as water harvesting. The

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stored water can be used for giving the lifesaving irrigation during prolonged dry

spells.


Salt Affected Soils and their Management Chandra Sheker

M.Sc. (Agri.) Department of Soil Science and Agricultural Chemistry, UAS, Dharwad, Karnataka *Corresponding Author eMail: [email protected]

Definition: Soils, in which concentration of salts is so high as to adversely affect plant growth and crop productivity, are called salt-affected soils from agriculture point of view.

Salt-affected soils are relatively more extensive in the arid and semi-arid regions compared to the humid regions. For any long-term solutions, it is, therefore, necessary to understand the mode of origin of salt-affected soils and to classify them, keeping in view the physico-chemical characteristics, processes leading to their formation and the likely approaches for their reclamation and successful management.

Extent of Problem

Global Scenario: The global extent of salt-affected land amounts to 1128 M ha. Global salt-affected soils are mainly saline, amounting to 60% of all salt-affected soils. Sodic soils account for 26% and saline-sodic soils for 14%. The majority of salt-affected soils is slightly affected (65%), followed by 20% moderately, 10% extremely, and 5% highly salt-affected soils. Regions with the largest salt-affected land areas are the Middle East (189 M ha), Australia (169 M ha), North Africa (144 M ha), and the former USSR (126 M ha) (Wicke et al., 2012).

Indian Scenario: About 6.74 mha land in India is under the adverse impact of salinity and sodicity. Large extent of states like Uttar Pradesh, Gujarat, Andhra Pradesh etc. are affected (Wicke et al., 2012).

Classification of Salt Affected Soils

1. Saline soils: Soils containing sufficient neutral soluble salts to adversely affect the growth of most crop plants. The soluble salts are chiefly sodium chloride and sodium sulphate. But saline soils also contain appreciable quantities of chlorides and sulphates of calcium and magnesium. The EC of these soils is > 4 dS m-

1, ESP is < 15 and pH is < 8.5. 2. Sodic soils: Soils containing sodium salts

capable of alkaline hydrolysis, mainly Na2CO3. The EC of these soils is < 4 dS m-1, ESP is > 15 and pH is > 8.5.

3. Saline – Sodic soils: Soils have both soluble salts and exchangeable sodium. The EC of these soils is > 4 dS m-1, ESP is > 15 and pH is ≥ 8.5.

The Effects of Salinity and Sodicity on Different

Soil Properties

Physical Properties: Elevated levels of exchangeable Na+ cause structural deterioration of the affected soils resulting in low pore volume and poor soil-water and soil-air relations in salt affected soils. Slaking, clay swelling, and dispersion are the main mechanisms involved in aggregate breakdown in sodic soils. Such conditions are unfavourable for the establishment and the growth of the plants.

Chemical Properties: Soils high in salinity and sodicity have high values of ECe, ESP, SAR, and pH. Salt-affected soils generally suffer from deficiencies of nitrogen (N), phosphorus (P), and potassium (K). However, their high pH also adversely affects the availability of micronutrients such as Fe, Al, Zn, Mn, and Cu.

Biological Properties: Microbial growth and activity are adversely impacted by increasing soil salinity, as high salt concentrations in soils causes' osmotic stress and dehydration of microbial cells. In addition to salt stress, Na+ toxicity; nutritional deficiency such as Ca2+ deficiency; toxic levels of other ions such as carbonate, bicarbonate, and chlorides contribute to decreasing microbial populations and activities in salt-affected soils.

Reclamation and Management Strategies

Physical Methods

Scraping is the temporary method of soil reclamation in which salt layer on soil surface.

Flushing is another method of desalinization. In this method accumulated salts on the surface is washed away by water.

Leaching is by far the most effective procedure for removing salts from the root zone.

Chemical Methods

Use of soluble salts of calcium.

Use of sparingly calcium salts like CaCO3.

Use of acid or acid formers like, sulfur, sulfuric acid, sulfates of Fe and Al, pyrites etc. Relative quantities of different chemical amendments required to correct soil alkalinity is given in Table 1.

Biological Methods

Phytoremediation using halophytic plants

Use of AMF (Arbuscular Mycorhizal Fungi)

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Amendment Chemical composition

Amt. equiv. to 1 kg of chemically pure

Gypsum (kg) S (kg)

Gypsum CaSO4.2H20 1.0 5.38

Sulphur S 0.19 1.00

Sulphuric acid H2SO4 0.57 3.06

Calcium carbonate

CaCO3 0.58 3.13

Calcium chloride

CaCl2.2H2O 0.85 4.59

Ferrous sulphate

FeSO4.7H2O 1.61 8.69

Amendment Chemical composition

Amt. equiv. to 1 kg of chemically pure

Gypsum (kg) S (kg)

Ferric sulphate Fe(SO4)3.9H20 1.09 5.85

Aluminium sulfate

Al2(SO4)3.18H20 1.29 6.94

Pyrite (30% S) FeS2 0.63 1.87

Reference Wicke B, Smeets E, Dornburg V, Vashev B, Gaiser T,

Turkenburg W, and Faaij A. (2012) The global technical and economic potential of bioenergy from salt-affected soils Energy & Environmental Science 4: 2669-2681.


Steenberg Effect in Relation to Application of Fertilizers S. A. Durgude and P. N. Patle

M.Sc., Department of Soil Science And Agril Chemistry, MPKV., Rahuri (M.S.) *Corresponding Author eMail: [email protected]

Introduction

Nutrient Deficiency: The quality or state of being defective or of lacking some necessary element: state of being deficient.

Nutrient Toxicity: The presence in the soil of a plant nutrient in such high concentrations that it is harmful to the plant, whether directly or by creating imbalance among other nutrients.

In the case of excess nitrogen we can observe vigorous vegetative growth coupled with dark green color. The vegetative growth is prolonged and crop maturity is somewhat delayed.

Acute Deficiency

Under this condition, nutrient level is extremely low, associated with severe symptoms and strongly reduced growth. Addition of the deficient element will result in significant increases in growth, development and crop yield.

Marginal or Latent Deficiency

Also known as “hidden hunger”. At this level, yield losses are considerable compared to adequate nutrient supply level.

Critical Range

This interval is referred as the concentration in plant below which a yield response to the applied nutrients occur

Overview critical, sufficient and toxic levels of plant nutrients

Element Critical level Sufficient level Toxicity level

Fe(mg/kg) <50 50-250 Non toxic

Zn(mg/kg) 15-20 20-100 >400

Mn(mg/kg) 10.0-20.0 20-300 >300

Cu(mg/kg) 3.0-5.0 5.0-20.0 >20

Steenberg Effect

The following graph is a visual representation of how plant growth and/or yield is affected by nutrient concentrations. The Steenberg effect: known under extreme deficiency, rapid yield increase can cause some decreases in nutrient concentration.

Relationship between plant nutrient concentration (on application of fertilizers) and plant growth/yield

Yield is severely affected when nutrient is deficient and when nutrient deficiency is corrected growth increases more rapidly than the nutrient concentration

Steenberg effect Results from dilution of nutrient in the plant by rapid plant growth

The concepts Luxury consumption: (Increase in concentration above critical range indicates the plant is absorbing nutrient more than its actual need or quantity needed for potencial yield), Critical range & Hidden hunger found above to Steenberg effect.

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(Reference – Havlin etal.2005 Soil fertility and fertilizers 8th edition)

43. SOIL SCIENCE 14788

Soil Quality and Method for its Assessment Shabnam1 and Meenakshi Seth2

Ph.D. Scholar Soil Science1 & Ph.D. Scholar Agronomy2

CSK Himachal Pradesh Agricultural University, Palampur *Corresponding Author eMail: [email protected]

The USDA Natural Resources Conservation Service defines soil quality as “The capacity of specific kind of soil to function, within natural or managed ecosystem boundaries to sustain plant and animal productivity, maintain or enhance water and air quality, and support human health and habitation. Changes in the capacity of soil to function are reflected in soil properties that change in response to management or climate”. Recently the concept of soil quality has been broadened to include attributes for food safety and quality, human as well animal health and environmental quality. Soil quality index is a function of the following parameters:

Soil quality index (SQI) = f (SP, P, E, H, ER, BD, FQ, MI)

Where, SP= Soil properties, P= Potential properties, E= Environmental factors. H= Health of animal and human, ER= Erodibility, BD= Biological diversity, FQ= Food quality safety, MI= Management inputs.

Maintaining the functions of soil is thus central to the achievement of sustainable development. However, no soil is likely to provide all those above functions, some of which occur in natural ecosystem and some of which are the results of human modifications. Soils have an inherent quality as related to their physical, chemical and biological properties within the constraints set by climate and ecosystems, but the ultimate determinant of soil quality is the land manager. Perceptions of what constitutes a good soil vary depending on individual priorities with respect to soil function, intended land use and interest of the observer. The assessment of soil quality can be viewed as a primary indicator of the sustainability of land management.

Soil Quality Assessment

Basically, two types of approach are employed for

evaluating the sustainability of a management system: (a) Comparative assessment and (b) dynamic assessment. A comparative assessment is one in which the performance of the management system is evaluated in relation to alternatives at a given time only in contrast, in a dynamic approach, the management system is evaluated in terms of its performance over time. However, soil is not directly consumed by humans and animals, and it is difficult to relate measurable soil quality indicators properties to specific soil functions or management goals. Because soils perform many simultaneous functions, however, the objectives of relating indicator properties to specific functions to processes are very difficult.

Over last years, researchers and farmers alike have tried to establish what are now widely called minimum data set of physical, chemical and biological properties that can be used as quantitative indicators in soil health assessment. Indicator properties that are frequently used are presented in table 1:

TABLE 1: Soil quality indicator properties

Physical Properties

Chemical Properties

Biological Properties

Bulk density, rooting depth, water infiltration rate, water holding capacity, aggregate stability, surface and sub-surface hardness

pH, EC, CEC, organic matter, mineralizable N, exchangeable K and Ca

Organic matter content, MBC, MBN, earthworms, enzymes, disease suppressiveness, active carbon, decomposition rate

Methods for Calculating Soil Quality

Among methods the following two methods are generally used for calculating soil quality indices: (i) statistical (ii) Conventional method

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Statistical: Soil quality indicators so determined are to be reduced to minimum data set (MDS) through a series of uni and multi-variate statistical methods using SPSS 10 software. Both parametric (RBD) as well as non- parametric statistics (Kruskal- Wallis X2) are to be used to identify quality indicators with significant treatment differences. Only variable with significant differences between treatments are to be chosen for the next step in MDS. Foe each significant variable Principal Component Analysis (PCA) may be performed. Within each principal component, only highly weighted factors i.e. those with absolute values within 10% of the highest weight, are to taken for MDS. For the reduction of redundancy and rule out spurious groupings among the highly weighted variables within each principal component, the multi variate correlation co-efficient may be used to determine the strength of relationships among variables. Well correlated variables are to be considered as redundant and also for the elimination from the data set. Summing up absolute values of elimination from the data set. Summing up absolute values of well correlated groups, the highest correlation sum is the best representing group. Apart from this, any non-correlated highly weighted variables are also to be considered important and retained in the MDS.

MDS Validation and Indicator Transformation (Scoring)

Multiple regression analysis using final MDS components as independent variables and each management goal attribute as a dependent variable is to be made. These regressions serve to check the MDS representation of management system objectives. After determining variables for MDS, every observation of each MDS indicator needs to be transformed for the inclusion in the soil quality index (SQI). Linear scoring technique may be used. However, soil quality indicators are to be ranked in ascending or descending order depending order depending on whether a higher value a higher value considers “good” or “bad” with respect soil functions. For more is better indicators, each observation divides by the highest

observed value such that the highest observed value receives a score of 1. For less is better indicators, the lowest observed value divides by each observation such that the lowest observed value recieves a score of 1.

Indicator Integration into Indices

Two soil quality indices may be used for comparison an additive SQI and weighted additive SQI. The additive index is the summation of scores from MDS indicators. From the summed scores, the additive soil quality index treatment means and standard deviations are to be calculated. In the weighted additive index after transformation, the MDS variables for each observation are to be weighed based on PCA results. Each PC explains a certain amount of variation in the total data set. The percentage is to be standardized to unity, provided the weight for variables chosen under a given PC. Then summing up the weighted MDS variable scores for each observation and calculated the treatment means and standard deviations. For all the indexing methods, SQI scores for the management treatment are to be compared using a two way ANOVA. Higher index scores are considered to be a mean better soil quality.

The concept of soil health and soil quality has considerably evolved with an increase in the understanding of soils and soil quality attributes. Soil quality cannot be measured directly, but soil properties that are sensitive to changes in management can be used as indicators. Soil health indicators are needed that help small-holder farmers understand the chain of cause and effect that links farm decisions to ultimate productivity and health of plants and animals. The soil health is better applied when specific goals are defined for a desired outcome from a set of decision. Therefore we can think of the soil quality as an evaluation process which consist of a series of action:

Selection of soil quality indicators and determination of a minimum data set (MDS)

Development of an interpretation scheme of indices and on farm assessment and validation

44. AGRICULTURAL CHEMISTRY 14841

Pesticides: Present Status, Regulatory Aspects and Future Challenges

Supriya Gupta, Pankaj Rautel and K. S. Bisht

Department of Plant Pathology, College of Agriculture GBPUA&T, Pantnagar-263145 *Corresponding Author eMail: [email protected]

Since the beginning of human advancement, it has been the major task of man to engage in a continuous endeavor to improve his living conditions. One of the main tasks in which human

beings have been engaged is acquiring enough sustenance to survive. Secondly, the control of insects, weeds, fungi and other pests of economic or public health is of utmost importance to our

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government. The task would have been impossible but for the Green Revolution of 1960, which has given reasonable hope for the country being not only self-sufficient in the production of adequate food and fodder but to become the largest producer of some important commodities. On the other side, pesticides have given rise to serious problems reckless use of pesticides may cause the pesticide residue to exceed a maximum limit, which imposes a threat to the quality and safety of crop and consumer health. In fact, since the incident in 1960 at Tule Lake, USA, where DDT use caused massive death of fish-eating birds, the concern about pesticide residue has been raised, which led to a worldwide debate on the value of pesticide use. Therefore, today the thrust is to review the health hazards associated with pesticide use, minimize pesticide residue and recommend future strategies for alternative and rational use of pesticides.

Trends in Pesticide Use

Presently, there are encouraging trends toward phasing out the toxic and persistent type of pesticides. Some new molecules are being developed which are biodegradable and having low mammalian toxicity, low residual life, and better compatibility with non-target organisms. Some of the other alternatives include the following:

1. Regulating pesticide use. 2. Use of biotechnology i.e., transgenic

technology using bacteria, fungi, viruses, etc. 3. Use of biopesticides i.e., use insect pests

enemies such as parasitoids, predators and insect pathogens.

4. Use of pesticides obtained from natural plant products such as neem extracts and other natural sources.

Regulation on Pesticides

The Government of India has taken steps to ensure the safe use of pesticides. The Insecticides Act, promulgated in 1968 and enforced on 1st August, 1971, envisages to regulate the import, manufacture, sale, transport, distribution, and use of insecticides, with a view to prevent risks to human beings or animals, and for matters connected therewith. Prior to this, four insecticides mainly used in the public health programmes were being controlled under the Drugs and Cosmetics Act, 1940. It was desirable as a prerequisite to the enforcement of the Insecticides Act, to evaluate the magnitude of pesticide pollution in the country and related health hazards to ensure their safe use for the benefit of the society. ICMR’s National Institute of Occupational Health (NIOH), Ahmedabad, and several other national laboratories, Agricultural universities and other R&D organizations have been engaged in toxicological evaluation of pesticides, synthesis of safer molecules and evaluation of environmental contamination due to

pesticides.

Pesticide Formulations

Pesticide formulation consists of one or more active pesticide ingredients plus other ingredients which have no pesticidal action i.e. inert ingredients. Inert ingredients generally include fillers, talc, petroleum distillate, solvents, wetting agents, extenders, emulsifiers, adjuvants etc.

Types of Formulations: Depending upon the intended use of pesticides there are different types of formulations. There are many problems we are facing in using the conventional pesticide formulations. High concentration of pesticides in WP formulation endangering human health and contaminating environment, organic solvents used in EC formulation are inflammable and enhance per-cutaneous toxicity by dermal penetration. To avoid these problems some of the newly developed modern formulations are Water Emulsifiable gel, Floating granules, drift less dust, macro and micro encapsulated suspension, hollow fibers, monolithic matrix, laminated structures etc.

Solids- Dust or powders, Granules, Pellets Tablets Particulates or Baits, Dry flowables, Wettable powders, Ear tag /Vapour strips, Seed treatment WDGs

Liquids- Suspensions Concentrate, Solutions, Emulsifiable concentrates, Gels, Aerosol, Ultralow volume concentrates, Micro emulsions, Suspoemulsions.

Gases- Fumigants sold as liquids or solids Pesticides, Non-target Organisms and Our

Environment: Regarding effect on non-target organisms, the most important publication was Rachel Carson’s best-selling book “Silent Spring,” published in 1962. She (a scientist) issued grave warnings about pesticides, and predicted massive destruction of the planet’s fragile ecosystems unless more was done to halt what she called the “rain of chemicals.” In retrospect this book really launched the environmental movement. She was focusing on the chlorinated hydrocarbons, such as DDT, and linking them to death of non-target creatures, such as birds. She argued that the death of non-targets occurred via two basic ways:

1. Direct toxicity - It was discovered that DDT was toxic to fish (especially juveniles) and crabs, not only to insects.

2. Indirect toxicity - related to its persistence. The indirect toxicity related to two principles: a) Bioconcentration- the tendency for a

compound to accumulate in an organism’s tissues (especially in fatty tissues for fat soluble organochlorines such as DDT)

b) Biomagnification- an increase in concentration up the food chain

Improvisation in Pesticide Use

Many of the harmful effects from applying chemical pesticides are observed not so much from pesticide use but from pesticide misuse. This includes over application, repeated application of

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the same pesticide, poor application technology, and even the use of pesticides to catch fish. It was suggested that rather than focus on new technologies it might be more effective to make sure that pesticides are used properly. This includes the improvement of application technology and sprayers, especially for low-income farmers. The condition and quality of the sprayer, and especially the nozzle, are very important. Under the best of circumstances, it is not easy for farmers to apply a fixed volume of chemical spray evenly over a fixed area. If the application technology is poor, farmers tend to apply far too much pesticide. Scientific community made approaches towards the developments of newer molecules which could be easily biodegradable, target-specific with very low mammalian toxicity. An efficient monitoring system which regularly tests food items for pesticide residues is a strong incentive for farmers to use chemicals wisely. One promising approach is HACCP - Hazard Analysis at Critical Control Points. This looks at the whole chain of pesticide distribution and use, and selects the particular points where action is feasible and will make an impact. Researches were also carried out to develop safer molecules which could undergo

photo degradation, microbial degradation as well as chemical degradation leaving very less amount of residues in the environment. The prime objective for this development is to give protection to the crops along with safety to the natural enemies of different pests as a whole safety to environment.

Future Challenges

To develop more and more new molecules having

Low mammalian toxicity

Less soluble in water

Leaching potential shall be less or absent

More biotechnological innovations to be directed intransgenic plants etc.

More innovative technology to be developed in application of pesticides, a special care shall be given on the nozzles, sprayer or applicator with an intention to minimize the loss of applied pesticide or target organisms

Minimization of residue load in ecosystem

More emphasis shall be given in bio-control agents

Research emphasis shall be given in innovations of more plant derived biopesticides.

45. AGRICULTURAL CHEMISTRY 14863

Mycotoxins and Mycotoxicoses Vinod Upadhyay1 and Akansha Singh2

1Junior Scientist, Regional Agricultural Research Station, Assam Agricultural University, Gossaigaon-783360, Assam

2Ph.D. Scholar, College of Agriculture, G.B. Pant University of Agriculture and Technology, Pantnagar-263145, Uttarakhand

Mycotoxins are secondary metabolites of moulds that exert toxic effects on animals and humans. The toxic effect of mycotoxins on animal and human health is referred to as mycotoxicosis, the severity of which depends on the toxicity of the mycotoxins, the extent of exposure, age and nutritional status of the individual and possible synergistic effects of other chemicals to which the individual is exposed. The chemical structures of mycotoxins vary considerably, but they are all relatively low molecular mass organic compounds. This article focuses on the most important ones associated with human and veterinary diseases, including ergot, aflatoxin, 3-nitropropionic acid, ochratoxin A, trichothecenes, zearalenone and fumonisins.

Ergot: Ergot is the common name of the sclerotia of fungal species within the genus Claviceps, which produce ergot alkaloids. The sclerotium is the dark-coloured, hard fungal mass that replaces the seed or kernel of cereal grains, especially rye following infestation. Ergot alkaloids are also secondary metabolites of some strains of Penicillium, Aspergillus and Rhizopus

spp., Claviceps purpurea produces ergotamine-ergocristine alkaloids, which cause the gangrenous form of ergotism because of their vasoconstrictive activity. The initial symptoms are oedema of the legs, with severe pains. Paraesthesias are followed by gangrene at the tendons, with painless demarcation. It was characterized by gastrointestinal symptoms (nausea, vomiting and giddiness) followed by effects on the central nervous system (drowsiness, prolonged sleepiness, twitching, convulsions, blindness and paralysis). The onset of symptoms occurred 1±48 hours following exposure; there were no fatalities.

Aflatoxins: Aflatoxins occur in nuts, cereals and rice under conditions of high humidity and temperature and present a risk to human health that is insufficiently recognized. The two major Aspergillus species that produce aflatoxins are A. flavus, which produces only B aflatoxins, and A. parasiticus, which produces both B and G aflatoxins. Aflatoxins M1 and M2 are oxidative metabolic products of aflatoxins B1 and B2 produced by animals following ingestion, and so

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appear in milk (both animal and human), urine and faeces. Aflatoxicol is a reductive metabolite of aflatoxin B1. Aflatoxins are acutely toxic, immunosuppressive, mutagenic, teratogenic and carcinogenic compounds. The main target organ for toxicity and carcinogenicity is the liver. Aflatoxin is a liver poison (hepatotoxin) in all species that consume it; however, ruminants tolerate it better than do monogastrics or poultry. It causes liver damage at higher doses and liver cancer at lower doses. Aflatoxins exposure can depress the immune system.

3-nitropropionic acid: 3-Nitropropionic acid (3-NPA) is a secondary metabolite of Arthrinium sp., considered to cause a form of acute food-poisoning called ``mouldy sugarcane poisoning ''The problem occurred during winter (February and March) in 13 provinces of northern China as a consequence of ingesting sugarcane that had been stored for at least two months and which was infested with Arthrinium sp. The incubation period is generally 2±3 hours following the ingestion of mouldy sugar-cane and the main clinical symptoms are vomiting, dystonia, staring to one side, convulsions, carpopedal spasm and coma.

Ochratoxins: Ochratoxins are secondary metabolites of Aspergillus and Penicillium strains. The most frequent is ochratoxin A, which is also the most toxic. Ochratoxin A has been found in barley, oats, rye, wheat, coffee beans, and other plant products, with barley having a particularly high likelihood of contamination. There is also concern that ochratoxin may be present in certain wines, especially those from grapes contaminated with Aspergillus carbonarius. It has been shown to be nephrotoxic, immunosuppressive, carcinogenic and teratogenic in all experimental animals tested so far. The symptoms developed after 24 hours of transitory epigastric tension, respiratory distress, and retrosternal burning. Acute tubular necrosis was found on biopsy.

Trichothecenes: The trichothecenes constitute a family of more than sixty sesquiterpenoid metabolites produced by a number of fungal genera, including Fusarium, Myrothecium, Phomopsis, Stachybotrys, Trichoderma, Trichothecium, and others. They are commonly found as food and feed contaminants, and consumption of these mycotoxins can result in alimentary hemorrhage and vomiting; direct contact causes dermatitis.

Diacetoxyscirpenol, deoxynivalenol, and T-2 are the best studied of the trichothecenes produced by Fusarium species. Deoxynivalenol is one of the most common mycotoxins found in grains. When ingested in high doses by agricultural animals, it causes nausea, vomiting, and diarrhea; at lower doses, pigs and other farm animals exhibit weight loss and food refusal. For this reason, deoxynivalenol is sometimes called vomitoxin or food refusal factor. Although less

toxic than many other major trichothecenes, it is the most prevalent and is commonly found in barley, corn, rye, safflower seeds, wheat, and mixed feeds. Of the naturally occurring trichothecenes, T-2 and diacetoxyscirpenol appear to be the most potent in animal studies. In addition to their cytotoxic activity, they have an immunosuppressive effect that results in decreased resistance to infectious microbes. They cause a wide range of gastrointestinal, dermatological, and neurologic symptoms.

Zearalenone: Zearalenone (previously known as F-2) is produced mainly by Fusarium graminearum and related species, principally in wheat and maize but also in sorghum, barley and compounded feeds. Zearalenone and its derivatives produce estrogenic effects in various animal species (infertility, vulval oedema, vaginal prolapse and mammary hypertrophy in females and feminization of males Ð atrophy of testes and enlargement of mammary glands).

Fumonisins: Fumonisins are mycotoxins produced throughout the world by Fusarium moniliforme and related species when they grow in maize. Fumonisins B1 and B2 are of toxicological significance, while the others (B3, B4, A1 and A2) occur in very low concentrations and are less toxic. Fumonisin B1 was found in much higher concentrations in the maize and sorghum from the affected households than from controls. Fumonisins affect animals in different ways by interfering with sphingolipid metabolism. They cause leuko encephalomalacia (hole in the head syndrome) in equines and rabbits; pulmonary edema and hydrothorax in swine; and hepatotoxic and carcinogenic effects and apoptosis in the liver of rats. In humans, there is a probable link with esophageal cancer.

List of the major classes of mycotoxins, the common food products that may be contaminated with mycotoxins, and the possible symptoms of affected individual

Mycotoxin Contaminated products

Symptoms of Affected individual

Aflatoxins Corn, peanuts, cottonseed, tree nuts, dairy products

Liver damage, intestinal bleeding, cancer

Ergot alkaloids Rye, sorghum, pasture grasses

Hallucinations, gangrene, loss of limbs, hastening of birth

Fumonisins Corn, silage Pulmonary edema, leuko encephalomalacia, esophageal cancer, neural tube defects, liver damage, reduced growth

Ochratoxins Cereal grains, coffee, grapes

Kidney and liver damage, cancer

Trichothecenes Wheat, barley, oats, corn

Feed refusal, diarrhea, vomiting, skin disorders, reduced growth

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Mycotoxin Contaminated products

Symptoms of Affected individual

Zearalenone Corn, hay Enlargement of uterus, abortion, malformation of testicles and ovaries

Management of Mycotoxins: Management of mycotoxins involves practices that are employed pre-harvest, during harvest, and post-harvest (including detoxification approaches). Pre-harvest strategies primarily consist of tactics designed to reduce infection by mycotoxin-producing fungi, and fall into these three categories: (1) genetic resistance and other cultivar characteristics, (2) cultural practices (planting & harvest dates, tillage

practices, crop rotation, plant population, irrigation, sanitation), and (3) crop protection chemicals (insecticides and fungicides) or biological control. Postharvest strategies for managing mycotoxins fall into the following general categories: (1) drying and storage management, (2) sorting or other physical separation, and (3) detoxification.

Prevention of Mycotoxicoses: a) Purchase grain or feed that is free of mycotoxins b) Remove grain or feed contaminants with mycotoxins c) Use of feed additives to bind mycotoxins

46. HI-TECH AGRICULTURE 14812

Protected Agriculture in Smart India M. S. Shah 1, Nidhi Verma 2 and Akhilesh Jagre3

JNKVV, Jabalpur, (M.P.) (Wheat Project, ZARS, Powarkheda)

Protected Agriculture

Use of technology to modify the natural environment that surrounds a crop in order to harvest a higher yield, greater quality, during an extended season.

Concept: Perpetual demand of vegetables and shrinking land holding drastically, protected cultivation is the alternative and drudgery-less approach for using land and other resources more efficiently. It ensures high productivity per unit area with the genetic potentially of the crop being fully exploited, off season vegetables can be grown which fetch high prices in the market, off season healthy nursery can be raised, good quality produce free from any blemishes and finally it is easy to protect the crops against pests. The greenhouses are usually covered structures of plastic film which allow the solar radiation to pass through it but traps the thermal radiation emitted by the plants inside. The CO2 released by the plants at night also trapped inside, which increases the rate of photosynthesis at day time. The evaporation from the soil and plant also raise the humidity inside.

Prerequisites for Protected Cultivation: Fully climate controlled, partially climate controlled, purely naturally ventilated greenhouse, Walk in tunnels, Insect proof net houses, Plastic low tunnels

Low Cost Greenhouse/ Polyhouse: Zero energy chamber made of polythene sheet of 700 gauge supported on bamboos with sutli and nails. Its size depends on the purpose of its utilization and availability of space. Like the greenhouse it has one opening kept azar for 1-2 hours during the day, especially in the morning to reduce the level of humidity inside. The structure depends on sun for energy. The temperature within polyhouse increases by 6-10oC more than outside. The solar

radiations entering the polyhouse is 30-40% lower than that reaching the soil surface outside.

Medium Cost Greenhouse/ Polyhouse: Slightly higher cost, a Quonset shaped polyhouse (green house) can be framed with GI pipe (class B) of 15 mm bore. This polyhouse has single layer covering UV stabilized polythene of 800 gauge. The exhaust fans are used for ventilation those are thermostatically controlled. Cooling pad is used for humidifying the air entering the polyhouse. The polyhouse frame and glazing material have a life span of about 20 years and 2 years respectively.

Hi tech Greenhouse/ Polyhouse: Consist of a sensor, a comparator and an operator. The temperature, humidity and light are automatically controlled. These are indicated through sensor or signal receiver. Sensor measures the variables, compare the measurement to a standard value and finally recommend running the corresponding device. This modern structure is highly expensive, requiring qualified operators, maintenance, care and precautions.

Photoselective Netting: Photoselective nets were designed to selectively filter different spectral bands of solar radiation, and/or transform direct light into scattered light. The spectral manipulation intends to specifically promote desired physiological responses, while the scattering improves the penetration of the spectrally-modified light into the inner plant canopy. Thus, the replacing of the traditional black shade net by either a Red, Yellow or Pearl nets (ChromatiNets™) of similar shading factors, resulted in 15-40% higher fruit production in different cultivars. The major response to the photoselective filtration was producing more fruits per plant, with essentially no reduction of fruit size or quality. Additional benefits relate to

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photoselective improvement of pest control. Protected agriculture with or without soil gives profitable results.

References Y. Shahak, K. Ratner, N. Zur, Y. Offir, E. Matan, H.

Yehezkel, Y. Messika, I. Posalski, D. Ben-Yakir ISHS Acta Horticulturae 807: International Symposium on Strategies Towards Sustainability of Protected Cultivation in Mild Winter Climate

47. HORTICULTURE 13541

Major Problems in Fruiting of Horticultural Fruit Crops P. L. Deshmukh1 and V. A. Bodkhe2

1Ph.D. Scholar, Department of Horticulture, Dr. P. D. K. V., Akola, Maharashtra. 2Ph.D. Scholar, Department of Horticulture, M. P. K. V., Rahuri, Maharashtra.


It is common that the fruit grower is often faced with difficult situation of poor fruiting in his orchard. The tree may be in good health and may not show any apparent cause of the malady. The growth and fruitfulness of a plant is greatly influenced by various external as well as internal factors.

I. External Factors

A plant is exposed to different phases of environment during the different stages of its life cycle such as germination, flowering, fruiting, harvesting, etc. These various phases of environment influence the blossoming and fruit setting. This environmental impact may render the plant fruitful or unfruitful. Let us see what are the main external factors influencing the fruitfulness of the plant.

A. Environment

The most important aspects of environment are temperature, rainfall, wind, light, etc. These factors can prevent or favour the pollination and fruiting.

1. Temperature: Temperature is a variable factor which is controlled by time, season, latitude, altitude, slope, plant cover, soil type, etc. Temperature profoundly influences reproduction, embryonic development and growth of a plant. Air temperature 25 to 30 degree C is the most favourable range for tropical plant. The optimum temperature for fruiting ranges from 22 to 28 degree C and it varies according to the fruit trees.

2. Light: Light supply is also important in determining the setting of fruits in deciduous trees (pertaining to the falling of leaves, fruits and petals of flowers). The development of stamens (male organ in the flower) and petals (each of the division of a corolla, the coloured part of a flower) in strawberry flowers is reported to take place only when the plants are exposed to long day light conditions.

3. Rainfall: Rainfall at blossoming is recognised as one of the most important limiting factors of fruit setting. Heavy rains drop down the newly formed flowers from the tree or may severely damage the vital organs of the flowers

such as stamens, pistils, etc. Consequently, there is very poor fruit setting or no fruit setting at all.

4. Wind: Wind is one of the most important agents in the transfer of pollen from stamens to stigma (the portion of ovary surface which receives pollen). Many plants such as walnut, aonla, etc. are wind- pollinated. A reasonable amount of wind at blossoming is necessary in securing good fruit set, but strong and desiccating wind will adversely affect the fruit setting.

B. Insect Pests and Diseases

Insects also play an important role in pollination. Bees and other pollen carrying insects work more effectively in a still atmosphere.

The flowers of many fruit trees are subject to the attack of various insect pests and diseases. The result is serious reduction in the fruit set. Mango hopper can attack mango tree at blossom and damage flowers to a great extent. It can even destroy whole orchard. Malformation of flower panicles in mango, and anthracnose, die- back and fruit-rot in citrus plants cause heavy losses through poor fruit set and blossom drop. The control of these pests pest and diseases and adopting suitable preventive measures before attack, will greatly: increase the fruit set.

II. Internal Factors

A. Sex Distribution

For proper setting of fruits presence of sufficient number of male and female flowers in a plant is necessary. But some plants (of many species) do not fruit because their flowers are having only one sex that is either male or female. So in such a case, the orchard must have a proportionate number of plants bearing male and female flowers. Otherwise fruiting will not take place. Ego papaya, mango, strawberry, fig, etc.

B. Heterostyly

This denotes the defective floral structure such as short styles and long filaments in some flowers and long styles and short filaments in other flowers. Due to this abnormal structure of flowers, self-pollination will be prevented and this will lead to poor fruit set

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C. Physiological Factors

These include premature or delayed pollination. When mature pollen grains are applied to immature pistils, they penetrate the styles and enter the ovules and if the ovules are not ready for fertilization, the flowers soon fall off. The health of the plant is affected due to this. Pollens from healthy trees germinate better than those from weak trees.

In some trees male and female sex organs develop and mature at different periods. This will inhibit the self-pollination of the perfect flowered plants (the perfect flowers are those which have both male and female sex organs). This is known as dichogamy. It is incomplete where there is overlapping of the seasons of maturity of sex organs, otherwise it is complete. Eg. Avocado.

D. Genetic Incompatibility

This is another cause of self-unfruitfulness. Genetic incompatibility is a condition in which the pollens of a variety are incapable of fertilizing the flowers of another variety, or of the same variety. Hybrids of distantly related plants produce self-sterility. These trees may blossom and bear flowers but they may be without pistils and petals. Numerous stamens also may be present but are malformed. Sometimes the ovules and the pollens of these flowers are fertile in themselves but fail to conjugate. Eg. Mango, sweet cherry, plum, pear and almond.

E. Nutritional Status of Plants

The nutritional status as affected by soil, water supply, manuring, soil culture and pruning also exert a profound influence on fruit set the growth and fruitfulness of a plant is greatly influenced by the relative proportions of carbohydrate and nitrogen. For the better development and satisfactory growth, a balance should be maintained between carbohydrate and nitrogen. This balance of carbohydrates and nitrogen in the plant is called C/N ratio.

The building up of a surplus food material (carbohydrate) i.e. over and above the requirement of plant's physiological activities and new tissue formation is a pre-requisite to fruitful condition of a tree. This accumulation may occur due to the rapid manufacture of carbohydrates or to their less utilization. The factors affecting this rapid manufacture are wider spacing in the orchard, light, water, nutrients and more favourable temperature. This surplus accumulation and vigorous growth of the plant can be brought down by the reduction in supply of water or nutrients (especially nitrogen) and also by lowering the prevalent temperature.

III. Methods for Inducing Fruiting

A. Mechanical Measures

It is very difficult to tackle related physiological, genetical and climatic factors responsible for unfruitfulness. However, certain cultural practices

such as root exposure, bending, pruning, notching, girdling, thinning and smudging can influence the accumulation of food materials and help in fruiting. These practices are discussed below.

1. Root Exposure: This is widely practised in India for inducing flowering and fruiting in oranges. About two months prior to blooming, the soil around the trees is removed near the main roots from an area of 60 cm radius. The main roots are exposed and fibrous roots are removed. The orchard soil is ploughed and the trees are allowed to go dry until the leaves wither and even some of them fall. It normally takes three to four weeks. After some leaves have fallen the exposed roots are covered with a mixture of soil and manure.

The root exposure is only practicable in dry weather when the soil moisture and nitrogen can be reduced to the minimum.

2. Ringing or Girdling: This is one of the well-known methods for inducing fruit bud formation. The operation consists of removing a strip of bark from branch or trunk of the tree. This will interrupt the downward movement of the carbohydrates and thus force them to accumulate above the ring. The branches which are 15 to 30 cm thick are ringed by removing a strip of bark about two cm wide all-round the base of the branch, a little above the point where it joins another branch. Ringing is sometimes resorted to induce flowering in over-vigorous mango trees. The heating of the ring and complete restoration of new bark on the ringed portion is highly imperative after fruits have set. Weak and exhausted trees should not be ringed.

3. Notching: Notching is also a sort of ringing of a branch above a dormant lateral bud. A small narrow strip of bark just above a dormant bud is removed. As a result, the bud is forced to grow into either a vegetative shoot or a mixed shoot containing both foliage and flowers as would be consistent with plant's natural habit of growth. It can be successfully practiced in fig trees. The effect of notching above the bud is three fold.

4. Smudging: Smudging is a practice of smoking the trees. The operation consists in burning brushwood on the ground and allowing smoke to pass through the centre of the crown of tree. The tree is smoked heavily and continuously for a week. Thereafter, light fires are made in the morning and evening for about a month upto the trees come into bloom. The smoking is discontinued as soon as the terminal buds begin to swell. The smudging is applied in mango to produce off-season crop.

5. Thinning of Fruits: This practice means the removal of a few young fruits from heavily bearing clusters or fruiting branches, so that the remaining fruits may have greater advantage of space, light, water and food. Due to reduced competition they can be expected to be larger in

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size, better in quality and brighter in colour. Thinning should be done soon after the

natural drop of young fruits has started i.e. a little before they have grown one fourth of their normal size. Thinning may invariably reduce the total yield of the tree. It is generally practised in apple, pear, plum, papaya, etc.

B. Chemical Measures

Of late, different chemicals or plant hormones have been used for inducing flowering and fruit setting in different fruit crops. It has been found that different concentrations of gibberellic acid (GA3), naphthelene acetic acid (NAA), 2,4-D, etc

are very effective in inducing flowering and fruiting. NAA (5 ppm) or GA3 (10 ppm) can be used for inducing flowering in mango. Weak concentration of NAA can also be used for inducing flowering and fruiting in pineapple. Figs, citrus, apple and pear all have been found to bear fruits by the use of auxins or GA3, or both in different concentration.

Similarly, chemicals especially pesticides can be used to check crops which sometimes are the main causes of unfruitfulness or poor fruit setting in these crops.


Rejuvenation Technology in Fruit Crops P. L. Deshmukh1 and V. A. Bodkhe2

1Ph.D. Scholar, Department of Horticulture, Dr. P. D. K. V., Akola, Maharashtra. 2Ph.D. Scholar, Department of Horticulture, M. P. K. V., Rahuri, Maharashtra.


Canopy development of perennial crops has a seasonal as well as lifelong developmental pattern. In general, canopy of fruit crops has crowded shape. Trees of natural shape and size are difficult to dealt with and even culminate into poor fruit yield in the subsequent years as the lower branches of canopy gradually turns inert and infertile. Likewise in fruit crops also, there is a decline both in quality and quantity of produce after certain years of age. As a result of which cultivation of such fruits becomes economically non-viable and non-remunerative. In several areas, plantations of improved varieties having good genetic potentiality have either gone unproductive or showing marked decline in productivity. In the recent past declining productivity of old and dense orchards existing in abundance which has became a matter of serious concern for gardeners.

For eradicate the problem of unproductive and uneconomic orchards existing in abundance, large scale uprooting and replacement of existing plantations with new plantation (rehabilitation) will be a long term and expensive strategy. This renders them uneconomical. Such exhausted trees can be rejuvenated by heading back of branches for the production of new shoots, which can bear

good crops in the years to come after rejuvenation.

Technique for Rejuvenating the Orchards

The decline of orchard trees starts with sparse appearance, yellowing and different type foliage symptoms, undergrowth and sickly appearance, dried-up top growth with small and less number of fruits. The branches of trees start to die from the top to downwards, ultimately resulted poor quality fruits (rough surface, thick skin and less juice). Such type of decline may be observed in whole orchards, on in a single tree or patches. Generally, canopy of fruit crops has crowded shape. Trees of uneven shape and size are difficult to deal with and even culminate into poor yield in the subsequent years as the lower branches of canopy gradually turns inert and infertile as well.

The technology also helps in maintaining the manageable tree height with open architecture and canopy of healthy shoots with outwardly growth facilitating penetration and utilization of light. Crowding and encroachment of trees with subsequent inefficient light utilization, is an obvious problem with older orchards, if trees are not well managed. The internal bearing capacity of trees also decreases with time, due to overcrowding and ultimately overshadowing of internal bearing wood.

Objectives of Rejuvenation

1. To increase the productivity and economic age of plant.

2. To convert the low yielding and inferior varieties/seedling origin trees into superior as well as high yielding trees.

3. To exploit the better root system of a plant who has survived in adverse soil and climatic conditions.

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4. To curtail the duration of gestation period. 5. To increase income per unit area of orchard. 6. To minimize the incidence of diseases and

pests.

Principles of Rejuvenation: Trees have latent buds which are activated by heading back of branches at certain point to put forth new sprouts which will grow into branches forming fruiting area.

When the branches are cut back, imbalance is created in root: shoot ratio which results in to arising of new shoots from plant to maintain balance it.

Points to be considered while Adopting the Rejuvenation Technology: Older plantations of seedling origin which have become senile can be adopted for top working either by grafting or budding with scion of superior varieties to upgrade seedling plantation with superior commercial varieties.

Plantation of commercial varieties where the canopy became over crowded resulting in reduction in yield can be rejuvenated by following canopy management.

Fruit crops had tendency of overlapping of canopy between 10 and 12 years of age depending on the nature of variety. Canopy is maintained by trimming and thinning in plantations which have overlapping branches.

Rejuvenation of Old/Unproductive Guava Orchards: A procedure to rejuvenate and restore the production potential of old unproductive and wilt affected orchards has been developed, which employs pruning of branches at different periodicity and at different severities. Crowding and encroachment of guava trees with subsequent inefficient light utilization is an obvious problem with older orchards, if trees are not well managed. The internal bearing capacity of guava trees also decreases with time, due to overshadowing of internal bearing wood.

The rejuvenation technology involves cutting of exhausted trees (showing marked decline in annual production) to the extent of 1.0 to 1.5 meter height above the ground level during May with the objective of facilitating new shoots. The newly emerging shoots are allowed to grow up to a length of about 40 to 50cm which could be attained in 4-5 months of pruning.

These shoots are further pruned out to about 50% of its total length in October to facilitate emergence of multiple shoots below the pruning point. Profusely emerging shoots in the inner canopy are also pruned out to promote branching. The multiple shoots developed as a result of October pruning are capable of producing flower buds for the rainy season crop.

Those farmers keen to harvest the rainy season crop can allow the shoots to bear buds and fruits. However, as the winter crop has more marketing edge and value due to quality with the onset of rainy crop, shoot pruning (50 percent) is

done again in May. This procedure of sequential and periodic pruning is continued every year for proper shaping of tree canopy and to ensure enhanced production of quality fruits during winter season.

Rejuvenation of Old Mango Orchard: In mango, 40-45 years old trees exhibit decline in fruit yield because of dense and overcrowded canopy. These trees do not get proper sunlight resulting in decreased production of shoots. New emerging shoots are weak and are unsuitable for flowering and fruiting. The population of insect-pests and the incidence of diseases increased in such orchards.

These unproductive trees can be converted into productive ones by pruning them. Intermingled, diseased and dead branches are removed. Thereafter, undesirable branches of unproductive trees are marked. At the end of December, these marked branches are beheaded at 1.5 to 2.0 meter from distal end and the cut portions are pasted with copper oxychloride solution. During March-April, a number of new shoots emerged around the cut portions of the pruned branches. Only 8 to 10 healthy and outward growing shoots are retained at proper distance so that a good frame-work is developed in the following years.

These rejuvenated trees are fertilized with 2.5 kg urea, 3.0 kg single superphosphate and 1.5 kg M.O.P. per plant. The half dose of fertilizers is applied in the month of February and the other half at the end of June. The plants are irrigated at an interval of 15 days especially in the months of April, May and June for healthy growth of new shoots. In the first week of July, 150 kg of compost per tree is also applied. Unwanted emerging new shoots are regularly removed to maintain the tree canopy. It also helps in getting proper nourishment to retained shoots. After two years of pruning new shoots come into bearing and the yield of fruit increases gradually. Thus, old and unproductive trees are converted in to productive ones.

Management Practices to be followed after Rejuvenation

1. Marking of the tree with white chock for rejuvenation pruning.

2. After marking cutting should be done from lower surface of the branch and later from upper surface to avoid cracking as well as bark splitting.

3. Application of cow dung or copper oxychloride on cut surface to check the microbial infection.

4. Ploughing of rejuvenated orchard and preparation of basin and irrigation channel.

5. Application of FYM @ 40-50 kg per plant soon after rejuvenation.

6. Insure irrigation soon after rejuvenation for shoot sprouting and proper development of tree canopies.

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7. Mulching around the tree with black 100 micron polyethylene film (100 micron equal to 400 gauges).

8. Take care of only emerged shoots. 9. Thinning of shoot by retaining only 4 to 6

outward growing, well-spaced and healthy shoot per pruned branch.

10. Good phytosanitary procedures are to be

adopted to manage the rejuvenated plants. 11. Regular observations for incidence of stem

borer. Pull out the caterpillar (trunk borer) mechanically by inserting iron spoke in the shelter holes.

12. Remove the insects and insert the swab of cotton soaked in monocrotophos and plug the holes with mud.


Cultivation of Banana in Chhattisgarh Chetna Banjare1 and Mridubhashini Patanwar2

1Ph.D. Scholar, Department of Horticulture, IGKV, Raipur; 2 Garden Superintendent, Bilaspur (C.G.)

Banana is most important major fruit crops grown in India. In respect of area it ranks second and first in production only after mango in this country. India leads the world in banana production with an annual output of about 16.820 metric tonne. In Chhattisgarh, major banana growing districts are Raipur, Durg, Bilaspur, Balrampur, Raigarh and Mahasamund. Leading district which covers maximum area for banana cultivation is Bilaspur (2450 ha) and Durg leads in production with 51585 metric tonnes in Chhattisgarh. In Chhattisgarh, bananas are so predominant and popular among people that poor and rich alike like the fruit. Considering the nutritive value and fruit value of bananas, it is the cheapest among all other fruits in the country.

Climate: Banana is essentially tropical plant requiring a warm and humid climate. It is day neutral plant. It can be cultivated in a temperature range of 10°C and 40°C with high humidity but growth is retarded at temperatures of 20°C and less and more than 35°C. Yields are higher when temperatures are above 24°C for a considerable period. Hot winds blowing in high speed during the summer month's shred and desiccate the leaves. In cooler climate, the crop requires longer time to mature.

Soil: Fertility of soil is very important for successful cultivation, as banana is a heavy feeder. Banana is one of the few fruits, which has a restricted root zone. Hence, depth and drainage are the two most important considerations in selecting the soil for banana. The range of pH should be 6.5-7.5. Alluvial and volcanic soils are the best for banana cultivation.

Varieties: Dwarf Cavendish (AAA): It is a popular commercial cultivar grown extensively for table and processing purpose. 'Basrai' is the leading commercial variety of Cavendish group. The average bunch weight with 6-7 hands and with about 13 fruits per hand is about 15-25 kg.

Robusta (AAA): It is a semi-tall variety, grown mostly for table purpose. It is a high yielding and produces bunch of large size with well-developed fruits. Fruit is very sweet with a good aroma. Bunch weighs about 25-30 kg. It requires

propping. Rasthali (Silk AAB): Its unique fruit quality

has made Rasthali popular and a highly prized cultivar for table purpose. Fruits are yellowish green throughout their development, but turn pale yellow to golden yellow after ripening.

Nendran (AAB): It is a popular variety where it is relished as a fruit as well as used for processing. Nendran is known to display considerable diversity in plant stature, pseudostem colour, presence or absence of male axis, bunch size, etc. Bunch has 5-6 hands weighing about 12-15 kg.

Red Banana (AAA): The colour of the pseudostem, petiole, midrib and fruit rind is purplish red. It is a robust plant with bunches weighing 20-30 kg under good management practices. Fruits are sweet, orange yellow coloured and with a pleasant aroma. It is highly susceptible to bunchy top, fusarium wilt and nematodes.

Propagation

Vegetative Method: Commercial bananas are seedless and propagated exclusively by vegetative means. The banana has a reduced underground stem, called the rhizome, which bears several buds. Each of these buds sprouts and forms its own pseudostem and a new bulbous rhizome. These daughter plants are called suckers. Banana is mostly propagated by rhizomes and suckers viz. sword suckers and water suckers. Suckers of 2-4 months age are selected. Other planting materials are whole or bits of rhizomes. The weight of the rhizomes should be 500 g-750 g. It should be 3-4 months age at planting.

Tissue Culture: Now-a-days banana plants are also propagated through tissue culture. Varieties like Shrimanti, Gross Michael and Grand Naine are commonly produced using tissue culture technique. Normally disease free plantlets with 3 - 4 leaves are generally supplied in pots for raising secondary nursery. Plants are initially kept in shade [50%] and as they harden, shade is reduced gradually. After 6 weeks, plants do not require any shade. Normally two months of secondary nursery is good enough before the plants to be planted in

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the field pits. Planting: Planting can be done in May-June or

in September - October

Methods of Planting

Pit method: Pits of 0.5mx0.5mx0.5m are dug for planting the rhizomes. However this method is very laborious and expensive. The only advantage is that no earthing up is required as planting is done at the required depth. This practice is not very popular at present.

Manure and Fertilizer: The fertilizer dose depends upon the fertility of soil and amount of organic manure applied to the crop. For a good yield, 40-50 t/ha of well-decomposed FYM is incorporated into the soil. The recommended fertilizer dose for optimum yield is as follows.

Fertilizer dosage for tissue culture banana is given below:

Days after Planting

Fertilizer Dose (g/plant)

Urea/ Ammonium Sulphate SSP MOP

30 45/100 125 50

75 90/195 125 85

110 110/245 125 85

150 110/245 125 100

180 90/195 125 100

At bunch emergence

- / - - 85

Intercultural Operations

Weed Control: Pre-emergence application of Diuron (1kg a.i./ha) or Glyphosate (2 kg a.i./ha) is effective in controlling grasses and broad-leaved weeds without affecting the yield and quality of banana. Double cropping of cowpea is equally effective in suppressing the weed growth.

Intercropping: Intercropping can easily be raised in banana plantation at the early stages of growth. Vegetable and flower crops like radishes, cauliflower, cabbage, spinach, chilli, brinjal, lady's finger, gourds, marigold, and tuberose can be

successfully grown as intercrop. Mixed cropping with arecanut coconut and cassava is a common and widely adopted practice in South India.

Desuckering: During the life cycle, banana produces number of suckers from the underground stem. If all these suckers are allowed to grow, they grow at the expense of the growth of the main plant and hence the growth of the sucker should be discouraged. Removal of unwanted suckers is one of the most critical operations in banana cultivation and is known as desuckering. Such suckers are removed either by cutting them off or the heart may be destroyed without detaching the sucker from the parent plant. Removal of suckers with a portion of corm at an interval of 5-6 weeks hastened shooting and increased the yield.

Earthing Up: In case of furrow planting earthing up should be done during rainy season to avoid water logging while during winter and summer the plant should be in the furrow.

Propping: Propping operation is carried out in areas with high wind speeds. Pseudostems are propped up with bamboo, especially, at the time of bunch emergence.

Removal of Male Flower Bud: Removal of male bud after completion of female phase is necessary. Once the process of fruit setting is over, the inflorescence rachis should be cut beyond the last hand otherwise it grows at the cost of fruit development. This helps in early maturity of the bunch.

Harvesting: Irrigation of banana plantations should be stopped well in advance of the harvest date, preferably a week. Temporary sheds should be erected near banana fields and all operations such as cutting into hands, application of fungicidal paste should be carried out under the shade. Bunches having malformed fingers, octopus-shaped hands, broken, torn or split fingers etc. should be rejected. Three quarters full stage is recognized by sharp angularities of the fingers.


Methods of Vegetable Preservation Gaikwad S. D. and Alekar A. N.

(Ph.D. Scholar), Department of Horticulture, Mahatma Phule Krishi Vidyapeeth, Rahuri. (M.S.)

Vegetables Certain vegetables will differ in their temperature, humidity and ventilation requirements for storage resulting in optimum quality and reduced incidence of disease or decay.

1. Onions: Harvest onions when the tops have fallen over and the necks have shrivelled. After removing the tops, place them in a spot to dry thoroughly and store in a well-ventilated area in hanging open-mesh bags or open crates. Prevent them from freezing. If

they do become frozen, do not handle them because of their sensitivity to damage. Discard any which become watery and develop a soft rot.

2. Potatoes: Dig and cure early potatoes in moist air for 1 to 2 weeks at 60 to 75 degrees. This will harden small cracks and prevent decay over longer storage periods. Keep them stored at temperatures of 70 to 75 degrees. They will last for 4 to 6 weeks under these conditions. Late potatoes will last longer than early

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potatoes since outdoor temperatures are cool at harvest time. For late potatoes, cure by holding in moist air for 1 to 2 weeks. Store them at temperatures in the range of 35 to 40 degrees in the dark. Potatoes stored at 50 degrees or lower may become sweet. To correct for this flavor change, hold them at 70 degrees for a week before use.

3. Beans and Peas: The best way to preserve legumes like beans and peas is to dry them. You can either pick the pods as soon as they are filled or a little earlier and spread them out to dry in a warm place, or pull the whole plants out of the ground and let them dry with pods intact over a frame. In either case, after the pods are dry they can be shelled and refrigerated at 0 degrees for several days then heated in an oven at 180 degrees for 15 minutes to kill storage pathogens and insects. Store in a moisture-proof container between 32 and 50 degrees F.

4. Cabbage: Harvest cabbage when the heads are firm. Heads can be stored for several months in plastic bags in outdoor pits. Another method is to harvest the whole plant and bury the heads in a soil mound with the roots sticking up. Cabbages can also be hung in the garage in well-ventilated plastic bags, however, do not put them in the basement because of the odor they give off.

5. Pumpkins and Squash: Pumpkins and squash can be kept for several months. Harvest them before the first frost leaving a piece of the stem intact. Cure for 10 days at 80 to 85 degrees in the field or near a furnace. This will harden the rind and heal surface wounds. Store pumpkins and squash in a dry place at 55 to 60 degrees. Above and below ideal temperature storage conditions will encourage decay or physical damage. Acorn squash do

not need to be cured before storage. Place them in a dry area for 35 to 40 days at 45 to 50 degrees. If they begin to turn orange, the temperature is too high. Pumpkins and squash do not store well in cellars or pits.

6. Sweet potatoes: Sweet potatoes can be kept for long periods of time if kept in proper storage conditions. After they are dug with care, they should be cured by holding them for 10 to 20 days at temperatures of 75 to 85 degrees. If outside temperatures are not in this range, move them close the furnace. Maintain high humidity by wrapping the container in cloth or covering with paper. Once cured, move to a cooler place where the temperature is 55 to 60 degrees F. Do not store at or below 50 degrees as they are especially prone to cold injury. Outdoor pit storage is also not recommended because of the increased decay potential.

7. Carrots, Beets, Turnips, Winter Radishes: Most root crops are best left in the garden until the nights are cold enough to warrant storage. Carrots left in the garden, if mulched well so that the ground does not freeze, can sometimes be kept until spring. Otherwise, dig root crops when the ground is dry, cut the tops back and wash the dirt off. Let them thoroughly dry, then store at 32 to 40 degrees under high humidity. Plastic bags work well for this. If stored in a cellar, you can fill a bin with moist sand and layer the root crops. Sand will prevent rodents from entering and create high humidities. Sphagnum moss or peat moss will also work in place of sand. Turnips should be stored separately from other vegetables because they will give off odors. They actually do much better if left in the garden as they can stand hard frosts.


Different Warm Season Turf Grasses Gawde N. V.1* and Bhondave S. S.2

1Ph.D. Scholar, Department of Horticulture, J.A.U., Junagadh-362001 (GJ) 2Former M.Sc. Student, Department of Horticulture, M.P.K.V., Rahuri-413722 (MS)


Warm Season Grass

Warm season grasses are of tropical origin and can thrive during the scorching summer heat. They are tough, resistant to drought and insect attacks but susceptible to the cold spells of winter. The grass thin out over time and has a low tolerance to many weed control herbicides.

1. Bahiagrass (Paspalum notatum): It is not an aggressive spreader but is a drought resistant turf and requires no irrigation. It does not require excessive fertilization. When fertilizer is applied, it

should contain iron, especially if the soil pH is 7 or more. It is beat used in sunny areas in warm humid regions. Its roots can extend upto 8 inch deep. It can tolerate moderate shade and thrives well along highways.

2. Bermuda Grass (Cynodon dactylon): Common Bermuda grass prefers full sun and is drought resistant. It is frequently used in home lawns due to the ease and economy of establishment. It is very aggressive grass. Common Bermuda has a medium texture. Cold tolerance is good but shade tolerance is poor. It

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can sustain on heavy traffic. It grows in tropical, subtropical and transition zone areas. It grows extensively on lawn areas, golf courses, sporting fields and coastal areas.

3. Hybrid Bermuda grasses: These are inter specific crosses of Cynodon dactylon and Cynodon transvaalensis. These hybrids do not produce viable seed and must be propagated by springs, stolons or sodding.

These grasses have more disease and weed resistance, greater turf density and fewer seed heads. Texture is finer and softer with more favorable color. Frequent fertilization and close mowing, edging and de-thatching are needed to keep them attractive.

4. Buffalograss (Buchloe dactyloides): It is tolerant to prolong drought and to extreme temperatures. It forms a fine textured, relatively thin turf with a soft blue green color. It is not adapted to shaded sites or to sites that receive heavy traffic. It is preferred for roadsides, school grounds, parks, open lawn areas, golf course roughs and cemeteries.

5. Carpet Grass (Axonopus fissifolius): It is also known as flat grass. It is a perennial, coarse leaved, creeping grass, flat stolons and a tall seed stalk with 2 branches at the apex. It will grow well in either sun or shade. It is native to the interior Gulf states and other tropical climates. It does not tolerate salt. It is found in fields, woods, along roadsides, pastures and lawns and is used in park, roadsides, airports and golf course roughs.

6. Centipede Grass (Ermocholoa ophiuroides): Centipede is native to China and South East Asia. Its texture is medium, slow growing but consider as an aggressive grass which can produce a dense, attractive and weed free turf. Its cold tolerance is fair and rate of establishment is also slow. Shade tolerance of this grass is good but in full sunlight.

Winterization: Centipede grass does not need a late fall application of fertilizer often referred to as a ‘winterization feeding’.

7. Dicondra: Dicondra is a dense, high quality cover, but not a true lawn grass. It is low growing with beautiful color having oval shaped leaves and used for low maintenance and erosion control areas. It grows well in partial shade, but does in full sun. It does not tolerate heavy traffic.

8. Kikuyu Grass (Pennisetum clandestinum): Kikuyu grass is a coarse textured, a light green, sometimes mistaken for St. Augustine grass. It can tolerate heat and thrives well under shady conditions. It also tolerates to disease incidence and susceptible to very low temperatures. Kikuyu grass is a low maintenance grass. It can tolerate low fertility and high heat.

9. Monkey Grass (Mondo): Monkey grass is an evergreen perennial used mostly as a ground cover. It works well as a path border, between stepping stones or flowerbeds, lawn and rock gardens. Plant are tufted and grow as high as 16 inches. Texture is fine to medium Monkey grass does not stand up to cold.

10. Saint Augustine (Stenotaphrum secundatum): It is also known as Charleston grass. It is native to the Caribbean, Africa and Mediterranean regions, and best adapted to subtropical climates. It has an attractive blue green color and forms a deep, fairly dense turf. It is susceptible to fungal diseases. Texture is coarse with poor cold and traffic tolerance with moderate shade tolerance.

11. Zoysia Grass: Zoysia grasses are native to China, Japan and other parts of South East Asia. This grass is commonly called as Manila grass. Zoysia japonica, sometimes called ‘Japanese lawn grass’ or ‘Korean lawn grass’. It is a coarser textured grass.

Zoysia tenuifolia is called Korean velvet grass. It is a very fine textured species but is the least cold tolerant of the three species.

Zoysia grass is extremely drought tolerant, good salt, shade, cold and traffic tolerance but the rate of establishment is very slow.


Marigold the Yellow Gold 1Latha S and 2Shivaprasad S G

1Ph.D. Scholar, Dept. of Horticulture, College of Agriculture, University of Agricultural Sciences, Dharwad-580 005

2M.Sc. (Horticulture) Dept. of Floriculture, College of Horticulture, University of Agricultural and Horticultural Sciences, Shimoga, Karnataka, India

Marigold is one of the important commercial flowers of India and being grown for its spectacular flowers, brilliant colours, delightful appearance, myriads of sizes, shapes, forms etc. It belongs to the family Asteraceae. Marigold is not only grown as an ornamental flowering and landscape plant but also for its natural carotenoid pigments, used for poultry feed. The pigments are added to intensify the yellow-orange colour of egg

yolks by adding it to the poultry feeds. Today, it is one of the most commercial flowers grown world-over and in India as well, accounting for more than half of the nation’s loose flower production.

Besides, all the above applications recently marigolds are grown commercially for extraction of carotene pigments mainly xanthophyll. The carotene extracted from petals are added to poultry feed for intensification of yellow colour of

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egg yolk. Supplementation of poultry feed with marigold pigments helps to improve colour of ornamental fishes as well as fish fillet. Lutein which is a major constituent of xanthophyll is used for colouring food stuffs, purified extracts of marigold petals containing lutein di-palmitate is marketed as an ophthalmologic agent under the name adaptinol.

Presently the global consumption of synthetic dyes is about 10 lakh metric tonnes against the natural dyes of about 15,000 metric tonnes. This demand gap can be met by extracting the natural dyes from plant source. One popular and potential source is marigold.

It is also beneficial in liver diseases, swelling of the liver, stones and skin diseases. Dried marigold infusions make good toners, and good calmer for the itchy eyes of hay fever. Some oil in a parsley compress is good for broken capillaries. A drop of calendula oil in a bath is good for psoriasis. Oil is distilled from the flower tops, and it is quite sticky, and viscous. It smells very strange - musky, woody, rotten even, rather like

the flowers themselves. Marigold petals have been used as the poor man's saffron to colour cheeses. Flower extracts acts as blood purifier. Pigments of this are good remedy for eye disorders. Marigold petals also have characteristics of anti-fungal, anti-bacterial and anti-inflammatory activities and these can be utilized for production of creams.

Essential oils and their products: Marigold oil has a sweet, fruity almost citrus like fragrance. It is medium in viscosity. They are basic raw materials for perfume, flavour and cosmetics industries. They are used in wide range of products.

Value added poultry food: Carotenoids are the major source of xanthophylls pigment for poultry food. Intensification of yellow colour of egg yolks and skin of laying hens. Dry petals of marigold flower contains about 90 % (w/w) carotenoids mostly compound of esters xanthophylls (Lutein). The petals are dry in such conditions that maximum carotenoids retain in them. These dry petals are finely ground in powder form and added in to the poultry food.


Cashew: Needs the Intervention of Precision Farming Anindita Roy

College of Agriculture, OUAT, Bhubaneswar, 751003, Odisha

Advancing knowledge in tree architecture, growth physiology, possibility of using promising cultivars, water management etc. has enabled farmers to adopt closer planting and maintaining reachable canopy by tailoring soil and crop management applications to fit in varying conditions in the field. This system is popularly known as Precision farming. It enables profitable cropping, high, regular yields and improved farm management practices, leading to higher productivity. Today new orchards are being attempted to plant in this system with a view to produce higher yield and increased profitably. Precision farming is a modern method of cultivation involving planting of trees densely, allowing small or dwarf trees with modified canopy for better light interception and distribution and ease of mechanized field operations. Control of pests and diseases, weeds and pruning of tree canopy can be carried out by machine, Irrigation and fertigation are automatically controlled. This system produces precocious cropping, high and regular yields of good quality fruits and low labour requirement to meet ever rising production costs.

Cashew (Anacardium occidentale L.), a member of Anacardiaceae family, is a native of Brazil and introduced in India by the Portuguese during16th century. It is cultivated in tropical regions on either side of the equator for its delightful nutritious kernel and apple. Cashew

kernel is a rich source of proteins (21%), fat (47.0%), carbohydrates (22.0%), minerals, vitamins and essential amino acids.

Precision farming: Precision farming is defined as an information & management system to identify, analyze and manage variability within fields for optimum profitability, sustainability & protection of the land resources. Its goal is not to obtain same yield everywhere, but rather to manage and distribute inputs on a site specific basis to maximize long term cost /benefit.

Benefits

It reduces input costs, decrease environmental pollution, balances between environment and economy.

Provides more profit, intensive financial turnover, higher yields and lower inputs for chemicals and fertilizers.

Proper Analysis of machinery efficiency i.e. fuel, lubricants, maintenance and profitability of particular crops.

The Junctions where Precision Farming could negotiate

Soil & Climate: The best soils for cashew are deep and well-drained sandy loams without a hard pan. Cashew also thrives on pure sandy soils, although mineral deficiencies are more likely to occur. Water stagnation and flooding are not congenial for cashew. Heavy clay soils with poor drainage

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and soils with pH more than 8.0 are not suitable for cashew cultivation. Areas where the temperatures range from 20 to 30°C with an annual precipitation of 1000 - 2000 mm are ideal for cashew growing. Cashew needs a climate with a well-defined dry season of at least four months to produce the best yields.

Planting of cashew: The technique of softwood grafting has found thoroughly standardize for commercial multiplication of cashew in a short time. In hard lateritic soils, pits of 1m x 1m x 1m size are recommended. It is essential to provide stakes and temporary shade with the locally available materials wherever necessary to reduce the mortality rate and achieve quicker establishment. After planting proper mulching needs to be done.

Mulching: Mulches are materials placed over the soil surface to maintain moisture and improve soil conditions. Mulching the cashew tree basins helps to conserve the soil moisture and to prevent soil erosion. With organic matter, it inhibits weed growth and reduces surface evaporation during summer and also regulates the soil temperature. This will not only conserve soil and moisture but also enable to enhance the growth of cashew. It also improves soil biology, aeration, structure (aggregation of soil particles) and drainage over time.

High Density Planting in Cashew Plantation

To get the maximum possible profit per unit of the tree volume without impairing the soil fertility accommodation of maximum possible number of the plants per unit area can be done.

Fertigation

The delivery of dissolved mineral fertilisers to the

roots of crops in the field using irrigation water is known as ‘fertigation’. The use of fertigation is gaining popularity because of its efficiencies in nutrient management, time and labour and have control over crop performance. Fertilisers suitable for use in fertigation systems come as technical grade salts (e.g. potassium sulphate), acids (e.g. nitric acid), bases (e.g. potassium hydroxide), polymers (e.g. polyphosphate) or chelates (e.g. iron EDTA). They are almost exclusively injected into the irrigation water already in solution (i.e. pre-dissolved in water).

It saves at least 20-40 percent in fertilizers, do not cause any clogging, reduces leaching, increases yields by 25 to 35 percent, reduces delivery costs. It has greater control over where and when nutrients are delivered. Adopting this type of technology allows growers to evolve their standard practices and benefit from the improved crop outcomes.

Conclusion: Though it is a crop of waste land, it’s a dollar earning crop. Employing precision farming productivity can be increased and primer position of country can be maintained.

References Mishra, J. N., Paul, J.C., and Pradhan, P.C. 2008.

Response of cashew to Drip Irrigation and Mulching in Coastal Orissa. Journal of Soil and Water Conservation, 7(3): 36-40.

Shikamany, S. D. 2001. Canopy Management of Tropical and Subtropical Fruit crops. Indian Journal of Horticulture. 58: 1-2.

Tripathy P, Sethi K, Patnaik A K. and Mukherjee S K. 2015. Nutrient Management in High Density Cashew Plantation under Coastal Zones of Odisha. International Journal of Bio-resource and Stress Management, 6(1):093-097.


Role of Integrated Nutrient Management in Vegetable Production

Chetna Banjare1 and Mridubhashini Patanwar2 1Ph.D. Scholar, Department of Horticulture, IGKV, Raipur; 2 Garden Superintendent, Bilaspur (C.G.)

Integrated nutrient management (INM) is an approach to soil fertility management that combines organic and mineral methods of soil fertilization with physical and biological measures for soil and water conservation. INM adopts a holistic view of plant nutrient management by considering the totality of the farm resources that can be used as plant nutrients.

Integrated nutrient management is based on three fundamental principles:

Maximize the use of organic material

Ensure access to inorganic fertilizer and improve the efficiency of its use

Minimize losses of plant nutrients

Role of Biofertilizers in INM

Different types of biofertilizers available at present among that Rhizobium is relatively more effective and widely used. Considering an average N fixation rate of 25 kg N/ha per 500 g application of Rhizobium, it is expected that 1 tonne of Rhizobium inoculants will be equivalent to 50 tonnes of nitrogen. On the other hand, Azotobacter, which is used in non-legume crops, has given inconclusive results. Similarly, Blue Green Algae (BGA) and Azolla have been reported to be effective in certain growing areas in the country. Meanwhile if BGA applied at 10 kg/ha fixes 20 kg N/ha, then 1 tonne of BGA has an

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equivalent fertilizer value of 2 tonnes of nitrogen. Another important role of biofertilizers is liberation of growth substances, which promote germination and plant growth. There are several constraints to effectively utilize and popularize the use of biofertilizers. Some of these constraints are:

Unlike mineral fertilizers, use of the biofertilizers is crop and location specific. A strain found ideal at one location may be ineffective at another location due to competition of native soil microbes, poor aeration, high temperature, soil moisture, acidity, salinity and alkalinity, presence of toxic elements etc.

Low shelf life of the microorganisms

Unlike mineral fertilizers, biofertilizers need careful handling and storage

Lack of suitable carrier material, for restoration and longevity in actual field conditions

Different Components of INM

There are various components of plant nutrients for INM which can be applied in an integrated way. Besides inorganic fertilizers as the major component, others include farmyard

Manure (FYM), composts, green manure crops, crop residues, crop rotation and bio fertilizers. Fertilization in a balanced way, improved crop nutrition maintain the soil fertility and of plant nutrient supply to an optimum level for sustaining the desired crop productivity through optimization of various plant nutrients in an integrated manner.

1. Chemical fertilizers: Chemical fertilizers are rich in nutrients. They are required in less quantity to supply nutrients as compared to organic manures. But continuous use of chemical fertilizers deteriorates the soil conditions. Therefore, chemical fertilizers should be accompanied by organic / biofertilizers.

2. Organic manures like FYM in situ, Vermicompost: It improves the bulk density of soil up to a layer of 25 cm. It reduces resistance to penetration and Supplements N up to 50% of the nitrogenous requirement of the crop. Increases available N and P use efficiency when combined with 100% of the recommended quantity of NPK and Biofertilizers.

3. Industrial waste various practices can be adopted to convert wastes into suitable products Convert all available biomass on the farm into compost instead of burning or wasting it.

4. Inclusion of legume crops in cropping system to fix the atmospheric nitrogen in the soil.

5. Use of Biofertilizers like azolla, blue green algae, and rhizobium etc.

6. Crop residues and Make use of cattle excreta as manure rather than as fuel

7. Green manuring either growing in the same field or incorporating of leguminous plant or leaves.

8. Crop rotations: It is most important INM strategy which is ignored by the growers that is crop rotation is a very important tool in sustaining nutrient supply. Legumes in rotation restore soil fertility in more than one way viz, some of the N fixed is left in the soil after harvest, improvement in soil properties, lesser disease and pest problem and better weed control.

Green Manure Improves Nutrient use Efficiency in various ways:

Using Green Manure and the cover crops which are incorporated into the soil when they are still green are called as green manures. Cover crop are also grown but are grown to protect soil from erosion when the vegetable grower not growing the crop. Because upper layer of soil is rich in organic matter and nutrient content, controlling erosion is an important method of conserving soil nutrients. Green manures and cover crops are both used to supply nitrogen and increase soil organic matter. Legumes crops such as alfalfa and Beans can fix between 45 kg and 91 kg of nitrogen per acre in one year. The grasses like rye without a legume will not increase the nitrogen content of the soil. These crops are used for increasing soil organic matter content. They can also retain the residual nitrogen from the previous crop and keep it from being lost by leaching. A mixture of both grasses and legumes can be used to obtain the advantages of each. Improved soil tilth from added organic matter improves root growth, which increases the capacity of a crop to take up available soil nutrients. Green manuring through Sesbania aculeate (dhaincha) is equivalent to 60 kg inorganic Nitrogen per hectare. Incorporation of mungbean after picking pods results in savings of 60 kg inorganic Nitrogen per hectare.

Besides above, Green Manure helps in

Increasing apparent use efficiency of K when combined with 50% of the recommended NPK.

Having residual effect on the next crop.

Minimizing the adverse effects of Fe in acidic lateritic soils.

Goals of INM

1. To maintain soil productivity. 2. To ensure productive and sustainable

agriculture. 3. To reduce expenditure on costs of purchased

inputs by using farm manure and crop residue etc.

4. To utilize the potential benefits of green manures, leguminous crops and biofertilizers.

5. To prevent degradation of the environment. 6. To meet the social and economic aspirations

of the farmers without harming the natural

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resource base of the agricultural production 7. To maintain or enhance soil productivity

through balanced use of mineral fertilizers combined with organic and biological sources of plant nutrients

8. To improve the efficiency of plant nutrients, thus limiting losses to the environment

9. To improve physical conditions of soils

How this INM Technology different from Conventional way of Farming?

Integrated nutrient management differs from conventional nutrient management in that it considers nutrients from different sources, notably organic materials, nutrients carried over from previous cropping seasons, transformation of nutrients in soil, In conventional farming, people gave more emphasis on yield through use of chemical fertilizers, use of high yielding varieties and chemical pesticides along with irrigation facilities.

In INM it integrates/combines the objectives of production with ecology and environment, that is, optimum crop nutrition, optimum functioning

of the soil health, and minimum nutrient losses or other adverse effect on the environment. Integrated Nutrient Management (INM) has to be considered an integral part of any sustainable agricultural system.

Advantages

1. Enhances the availability of applied as well as native soil nutrients

2. Synchronizes the nutrient demand of the crop with nutrient supply from native and applied sources.

3. Provides balanced nutrition to crops and minimizes the antagonistic effects resulting from hidden deficiencies and nutrient imbalance.

4. Improves and sustains the physical, chemical and biological functioning of soil.

5. Minimizes the deterioration of soil, water and ecosystem by promoting carbon sequestration, reducing nutrient losses to ground and surface water bodies and to atmosphere.


Hydroponics in Rajasthan Devraj sisodiya, Dr. Mamta Meena*, Jayendra Chouhan and Anupam kumar

Assistant Professor* and Student’s, Suresh Gyan Vihar Universirty, Jagatpura, Jaipur-302017

INTRODUCTION: Growing plants in water is very old method but only few plants grown in water earlier, research started in this filed when Franis Bacon work published in in book Sylva Sylvarum in 1627 and water culture become a popular research after that. In1842a list of nine elements believed to be essential for plant growth had been complied. In 1929, William Frederick and Gericke of the University of California at Berkeley began publicly promoting that solution culture be used for agriculture crop production. This technique also adopted by NASA for its controlled ecological life support system.

(Cauliflower in Hydroponics)

Methods of Hydroponics

In nature soil act much like a “sponge” for water and nutrients. It “holds” the water and nutrient within reach of the plants roots. The soil itself isn’t consumed by the roots. If the plants roots receive all the things that they need soil isn’t necessary at all. In hydroponics water play role of soil and provide all the nutrients and minerals required by plants.

Several different approaches for growing plants hydroponically are:

1. Immersion/Static solution-This technique describe growing plants where the roots are constantly immersed in a nutrient solution will be oxygenated by an aquarium style air pump.

2. Continuous flow solution- It is similar to immersion but the solution is constantly moving past the roots of the plants.

3. NFT (Nutrient Film Technique) - is similar to continuous flow, but has one important difference. The roots are not totally immersed in the nutrient solution rather the roots are primarily surrounded by air (to allow oxygen uptake) and have a thin film of nutrient solution running in the bottom of the channel.

4. Drip system-It generally consists of delivering nutrients to a plant via a dripping mechanism. Typically pump is used to move nutrient

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solution above the roots where it will tickle down over the plants roots.

5. Ebb and flow-is a fancy way to describe a “flooding” system. Typically the plants sit in a water tight tray on predetermined schedule the tray will flood with nutrient solution. This cycle allows the plants to uptake water and nutrients but also have dry cycles where they can uptake oxygen.

6. Aeroponices - is an advanced hydroponics technique where the roots of plants hang free. Typically, plants reside in net pots which allow the roots to hang down in open air. The roots sprayed w nutrient solution. This spraying process delivers highly oxygenated nutrient solution directly to the roots of the plants.

Why Hydroponics in Rajasthan

Indian agriculture has a very vast, Almost we have all the types of climate cold, moderate or high temperature and grow number of fruits and vegetable, but then also we are lacking in production because unequal productivity of land. Some area rich in production and other hand we have dry states like Rajasthan and Gujarat. For competitive with developing world and want to be first in terms of agriculture production especially in horticulture we need to adopt techniques like hydroponics in Rajasthan where most part is dry and water is in scare.

(Tomato in hydroponics)

This technique is boon for horticulture development in Rajasthan. Hydroponics provide reuse of water, less laborious, increasing food production stability, providing higher yield and most important thing off season production when market prices high. This technique is very successful for growing tomato (cherry tomato), cucumber, lettuce, red cabbage, chilly, Bassel, all this cost high when important from other country or states. When this commercially grown in Rajasthan only, cost reduce almost half. Rajasthan have very good marketing for all this vegetables due to its high demand in hotels, fast food chain,

and foreign food service. High demand of organic food. Hydroponically grown vegetables and fruits are free from pesticides, insecticides and fully organic in nature.

Advantages of Hydroponics

Through hydroponic gardening; plants can be grown anywhere as long as their growth requirements are met.

It uses only 1/20th of water compared to traditional (soil based) gardening.

It provides a sterile environment for plant production. This technique does not require pesticides, fertilizers and other chemicals, as there’s no chance of damage due to soil-borne diseases or pests.

Crops grow two times faster in hydroponic gardening. It provides controlled environment, and yield is doubled leading to more production from same amount of space.

It needs 20% of less space in comparison to soil based gardens, as plants with small roots can be grown closer to each other.

Run-off in traditional gardening can lead to environment degradation due to high proportion of calcium, phosphorous and potassium content dissolved in it. But in hydroponic systems; water can be reused multiple times leading to water conservation with less expense incurred on it.

There’s no-doubt in the fact that hydroponics involves less labor. Upkeep is also minimal.

There are no soil setup and testing hassles.

Plants grown through this technique are healthy and have better nutritional value. It has been proved that vitamin content is 50% more in hydroponically grown plants as compared to conventional ones.

It is easy to harvest in this type of gardening.

There are no worries about the changing seasons, as crops can be grown all year round.

Disadvantages of Hydroponic

Initial set up cost of hydroponic system is high. It requires constant supervision.

These gardens can also become susceptible to power outage; in this case plants will dry out. If this ever happens, you have to manually water your garden.

Water-based microorganism can be easily introduced.

Technical knowledge is required for growing plants through hydroponics.

Problems and Solutions: Till now very few examples of hydroponics in Rajasthan. This is limited to research stations or educational institutes, not a single example of commercial production of fruits and vegetables hydroponically. There are challenges like high initial cost, required technical knowledge, high temperature, polluted water (high in salt contain) and lack of government support financially as well

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as technically. But this problems can be solved by establishing hydroponic material manufacturing industry which reduce initial cost because all the material we import from other countries, using purified water, exhaust fan for maintaining temperature, chaining shape of kit according to

our suitability of crop and more research required for its commercial popularization, providing technical knowledge to farmers and government needs to provide subsidy for hydroponic production.


Advance Production Techniques of Vegetable Cultivation Sanjivani P. Gondane

Ph.D. Scholar, Department of Horticulture, MPKV, Rahuri (Maharashtra) *Corresponding Author eMail: [email protected]

Diversification in agriculture favour to horticultural crops is to be looked as a means to ensure food and nutrition security as well as higher profitability. As long as production of high value crops remains relatively more profitable as compared to alternatives, it is feasible to promote crop diversification. Vegetable is gaining importance worldwide as it gives more nutritious food per unit area to the human being. India has an advantage of producing almost all types of tropical, temperate and exotic vegetables because of varied climatic conditions. Different production systems and some modern methods of cultivation are existing in India to produce high quality vegetables to fulfill the consumer’s requirements

Peri-Urban/ Market Garden: Peri-urban agriculture play important and potential role in increasing food security, employment and income generation, poverty alleviation, community resource development, waste management and environmental sustainability. With the rapid industrialization, growing urbanization and higher employment opportunities and income level, purchasing capacity is multiplying and awareness for nutrition is also increasing which creates increasing demand of vegetables in urban areas. In recent years, green belts are being developed around big cities, which can provide a very intensive and profitable network of small farms specialized in production of perishable vegetables for consumption by the urban consumers. Indian consumers prefer fresh, green vegetables than processed products which provide a business opportunity to the farmers located nearby the big cities or towns generally referred as peri-urban areas to meet the requirement of consumers and earn higher profit. The nearby market is main focus of this production system and it is also called as market gardening. The most important consideration is to develop a clearly focused marketing plan before any vegetable crops are planted. Diversified crops are grown in peri-urban vegetable farms. Diversified vegetables may include like baby corn, sweet corn, gherkin, red and yellow coloured sweet pepper, leek, bunching onion, broccoli, Brussels sprouts, celery, parsley, endive, chive, pak-choi, asparagus, artichoke and

a few others. The specialty vegetables are becoming popular to meet the demands of consumers, restaurants and hotels in big cities.

Home/Kitchen Garden/Nutrition Garden: In urban areas where home space is limited, vegetable garden may be confined to backyard, hence sometimes called backyard garden. Availability of fresh green vegetable and providing nutrition to the family is the main consideration of home garden. Many people enjoy raising vegetables in home garden and consider it as a pleasant way of exercising and economizing on food costs. Its main purpose is to provide a supplementary source of essential nutrients and variation in the diet for the family. Kitchen wastes can be utilized for making of vermicompost which will provide source of nutrients to vegetable crops. Family members generally meet the labour requirement of home garden.

Community/School Garden: Growing fresh vegetables in a common area of village belonging to community or school may be helpful for providing nutritious foods to school going children. Protein rich vegetable like mostly legumes and vegetables rich in Ca and Fe like beet leaf, amaranthus, Vitamin A rich vegetables like carrot, beet leaf should be preferred. School garden can be a place of experimental learning about techniques of vegetable growing and a motivation for getting better nutrition through diversified foods. This type of activity creates sense of cooperation, discipline and responsibilities among school children as well. The techniques of vegetable growing are similar to home garden.

Truck Farming: Large scale production for transportation by trucks to distant markets is an extensive farming system. It is for off-season supply of a particular vegetable to markets away from the growing areas. The well-known examples of distant marketing and off-season supply include onion and tomato from Maharashtra and Gujarat to north India (Delhi, Chandigarh), tomato from Kolar (Karnataka) to Kolkata. Recent developments in infrastructure, like roads / highways, rapid transport trucks and rail, and storage have facilitated truck farming. It

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is thus not necessary now to grow only those vegetables, which are less perishable than others.

Cooperative Farming: Few cooperative societies are enterprising farmers for supply to distant markets. There are not many instances of cooperative farming of vegetable crops in the country. The farmer’s cooperative societies supply vegetables at a pre-fixed price which collects and transports the vegetables from cooperative farms and sells them at their vegetable outlets established at several locations.

Contract Farming: Contract farming is a partnership between agribusiness/marketing firms and farmers. Contract farming is an important means to have an assured access to desired products or a quantitative and qualitative control over material supplies without actually engaging itself in farming. Firms may provide inputs, technology and services to farmers as a part of contract. Through contract farming, the firm can shift and/or share some of these responsibilities with farmers, and secure supplies at a lower cost. For farmers, contract farming serves as an assured market for their produce at their doorsteps, reducing marketing and transaction costs and also price risk. Availability of an assured market also acts as an incentive to farmers to use quality inputs, adopt improved technologies and scale up their production systems. With the modernization of retail industry, many companies will enter into contract farming for fresh and specialized vegetable cultivation like seedless watermelon, baby corn, lettuce and many others.

Container gardening: In urban areas mainly in big cities, land is a big constraint for home/kitchen garden, many types of vegetables can be grown well in containers and space available in backyard, terrace, varandah, balcony can be utilized for this purpose where sunshine is easily available. The large volume is needed so the pots hold enough water to get through sunny days. Pots should have plenty of drainage holes in the bottom and are nearly as tall as they are wide. Use the right potting media. Containers or pots should be filled with a mix of soil and well decomposed farm yard manures (FYM). Liquid fertilizers combining N, P and K in a proper ratio is also being popular for providing nutrients to plants. Generally we should grow those vegetables which are facilitates multiple harvest like tomato, leafy vegetables etc. instead of single harvest like cabbage or cauliflower etc.

Floating Garden: Floating garden is a kind of small artificial island constructed on a freshwater lake in order to facilitate early production of vegetables and increase the availability of land for agriculture. The vegetable cultivation inside the lake on floating garden is basically organic in nature without much use of chemical fertilizer or pesticides. Maize is planted with beans, tomato, potato and other cucurbits. Maize provides protection from chilly wind to many vegetables.

Diara Land /Riverbed Cultivation: Cultivation of crops on river bed areas called ‘diara’ land. The fresh silt and clay which deposits every year during monsoon months makes the lands of the river banks suitable for growing vegetable crops. Several cucurbits, like gourds and melons are grown in river basins in many states.

Precision Farming: In order to optimize the input or maximizing the crop yield from a given quantum of inputs is referred to as precision farming. It is the application of technologies and principles to manage spatial and temporal variability associated with all aspects of agricultural production. Precision farming can improve the productivity or reduce the cost of production and diminish the chance of environmental degradation caused by excess use of inputs.

Protected Cultivation

Is a framed structures covered with UV stabilized plastic films in which crops are grown under partially or controlled environment conditions. It is important to produce better quality of vegetables, obtained higher productivity, raising of nurseries and hardening of plants, better insect & disease control & reduced use of pesticides, off-season cultivation and efficient use of resources. The cultivated plants are offsetting the detrimental effects of prevailing biotic and abiotic factors. Structures and environment control measurers employed isolate this cultivated space allowing cultivation in unfavourable ambient conditions in reasonably close to optimal conditions. It can be profitably used for growing high value vegetable crops like, tomato, cherry tomato, coloured peppers, parthenocarpic cucumber, healthy and virus free seedlings production in agri-entrepreneurial models. Mulching, polyhouse / greenhouse, zero energy naturally ventilated greenhouses for high value vegetable cultivation, low Tunnels, off season vegetable cultivation under walk in tunnels, vegetable cultivation under shade nets, insect proof net houses are used for safe vegetable cultivation.

Hydroponics: Hydroponics is a branch of agriculture where plants are grown without the use of soil. The nutrients that the plants normally derive from the soil are simply dissolved into water. The plant’s roots are suspended in, flooded with or misted with the nutrient solution so that the plant can derive the elements it needs for growth. The plant simply needs the minerals from the soil. This is the basic premise behind hydroponics.

Nutrient Film Technique (NFT): It is a water-based system that requires no soil or mediums. Plants are grown with roots contained in a plastic film, trough or PVC pipe. Nutrient-laden water is re-circulated through the system, bathing the roots. This system is still popular for short-term crops, such as lettuce and leafy vegetables, where the plants are sold with the roots intact.

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Ebb and Flow Systems: It requires a medium, such as perlite, where main purpose is to provide stability for the plant’s roots. Ebb and flow systems include a tray in which the plant is placed in a medium; below the tray in a separate container is a reservoir containing water and mineral solutions. The water from the reservoir is periodically pumped up into the tray. This floods the tray and allows the plants to absorb water and nutrients. Gradually, the water drains back into the reservoir due to gravity. Ebb and Flow systems work best with small plants like herbs and are typically used in smaller hydroponic setups, such as those in the home.

Drip Systems: It is set up almost identically to

an ebb and flow system, although instead of water being pumped through one large tube, it is pumped through many small tubes and drains onto the top of the plants. This system is ideal for plants that do not yet have a developed root system. It works best with smaller plants.

Aeroponics: It is another water based system, which, like NFT, requires no medium. Plants are suspended on a tray, with their roots freely dangling below. The entire tray is placed into a box that has a small amount of water and nutrient solution in the bottom. A pump system is used to draw the water up, where it’s sprayed in a fine mist onto the entire plant and root in a continuous manner.

57. GENETICS 14800

Plant Morphological Traits and Tri-Trophic Interactions S. Routray

Ph.D. Scholar, Department of Entomology, Orissa University of Agriculture and Technology, Bhubaneswar, Odisha-3


Tri trophic interactions mainly focus on effect of plants on herbivores, natural enemies and their interaction. Such effects may be genetically variable among plants and/or induced in individual plants by herbivore attack, and are mediated by primary plant attributes (i.e. nutritional quality and physical structure) and defense-related products (i.e. secondary metabolites and plant volatiles). The study of tri-trophic interactions is important in order to understand natural species interactions and to manipulate them in pest control.

Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically, plant toxin-, plant nutrient-, and/or physically mediated (through morphological traits).

Plant Morphological Traits Mediated Interactions

Aspects of plant morphology may influence the performance of both pests and natural enemies and their interactions. Sometimes they can influence directly (trichomes) or in associated with secondary metabolites (glandular trichomes) affecting multi-trophics.

Plant Surface: Plant surfaces play a critical role in pest–plant interactions, influencing insect behavior (such as attraction, retention, and host choice), feeding (such as attachment and accessibility of nutrients), and dispersal (by impeding insect movement). Leaf surface structures that defend the plant from herbivores, such as leaf toughness, cuticle thickness, epicuticular waxes, trichomes and spines, can have direct and indirect effects on natural enemies. An indirect effect can occur if physical

defense traits, such as leaf toughness, delay the development of herbivores.

Trichomes: Directly trichomes are physically disruptive to natural enemy movement. In general, trichomes have more harmful than beneficial effects on predators, although most of these effects are sublethal. The functional response or attack rate of predators and parasitoids is typically lower when their prey or hosts are found on plants with greater trichome density.

These interactions have significant implications for pest management; for example, biological control is possible on glabrous cucumber varieties, but is seriously hindered on those with dense trichomes due to the reduction in searching efficiency by the parasitoid Encarsia formosa attacking greenhouse whiteflies Trialeurodes vaporariorum. The effect of trichome density on natural enemy movement can be a function of the relationship between natural enemy size and trichome spacing. The searching behaviour of the parasitoid Trioxys indicus of Aphis craccivora is affected by the foliar pubescence of the aphid host plants.

Epicuticular Waxes: Surface waxes on leaves,

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for example, can reduce the searching efficiency of natural enemies by decreasing their ability to grip the plant. Predation by Hippodamia convergens was increased on Pisum sativum or Brassica oleracea plants with reduced wax leaves when compared to normal wax plants. Predators walked faster, spent more time walking, and covered more leaf area on glossy leaves compared to normal wax varieties. In another case the foraging behavior of the braconid wasp Diaeratiella rapae was reduced on the leaves of cauliflower varieties for its aphid host Brevicoryne brassicae with heavy wax blooms. Wasps on the variety with a heavier wax bloom foraged more slowly, groomed more often and for longer periods of time, fell from the leaves more often, took longer to find colonies of aphids, and attacked them at a lower rate than wasps foraging on the variety with a lighter wax bloom.

Leaf Domatia in Plant-Pathogen-Predator Interactions: Leaf domatia are small hair-tufts or pockets on the abaxial surface of leaves that have been found in nearly 300 plant families. Leaf domatia mediated a mutualism between plants and predatory or fungivorous arthropods (Axel Lundströem, Swedish naturalist). Many crop plants, including coffee, grape, and walnut, are endowed with natural leaf domatia. Artificial domatia has also been incorporated in cotton varieties. Wild and cultivated grape plants show variation in the presence and size of leaf domatia that are inhabited by tydeid mite. Tydeid mites are voracious consumers of the phytopathogen powdery mildew, a major pest of grapes. Leaf domatia benefit predators and fungivores by providing a refuge (from their own enemies) and a favourable microclimate. Domatia do not appear to have high costs in terms of energetic drain or ecological blunders, although this issue has not received much attention. The morphological attributes of plants may also have a direct impact on herbivores.

Plant Architecture: Two components of plant architecture can readily be determined by the biological control practitioner: plant size and structural complexity. The size of a plant directly affects the total area that must be searched for pests. In the absence of specialized adaptations that help them find a pest, natural enemies tend to be less efficient on large plants because they have

a greater amount of surface area to cover than those on smaller plants.

It affects the dispersion of herbivores on a host plant, which may in turn affect searching behavior and host-finding abilities of natural enemies. For example, the leaves of winter wheat varieties developed for resistance to Russian wheat aphid Diuraphis noxia remain flat, compared to susceptible varieties whose leaves furl in response to aphid feeding, exposing them to disturbances such as wind, rain, and predators inducing them to fall from the plant. Trichogramma nubilale can more easily find and parasitize European corn borer eggs on artificial leaves with a simple shape than on those whose area is distributed among smaller leaflets. Aspidiotiphagus citrina is a wasp that parasitizes euonymus scale. Lower rates of parasitism by this wasp were observed on dwarf varieties of Euonymus japonica with small, closely packed leaves.

Structural complexity can also affect the searching ability of predators who look for prey on plants by walking along stems, leaf edges, or midribs. Lady beetles and minute pirate bugs are among the groups of insects with this kind of searching behavior. For example, lady beetles reduced aphid numbers on leafless varieties of peas more quickly because the search area was less complex.

Size and Morphology of Certain Plant Structures: Certain plant structures confer resistance to herbivores can affect biological control by altering where pests feed, how long they are exposed and how apparent or accessible the pests are to natural enemies, particularly if plant morphology can delay internally feeding pests from entering the plant’s tissues. An example would be husk tightness and length in sweet corn plants conferring resistance to H. zea larvae attempting to enter the ear and feed on developing kernels. Plant structures may also act to hide the herbivore from its natural enemies. For example, open-leaf brassica varieties, such as Brussels sprouts, have higher parasitism on P. rapae compared to heading varieties, such as cabbage, due to larvae being able to feed in leaf folds protected from parasitoids. Furthermore, the size of plant structures impacts the ability of parasitoids to oviposit in pests, particularly if larger fruits allow pests to feed deeper than the parasitoid’s ovipositor can reach, creating “enemy-free space” and potentially facilitating host switching by pests.

Conclusions: Moreover, physically mediated traits are known to function together with other traits to deter herbivory, but physical plant defenses are also responsible for increasing or decreasing herbivores’ vulnerability to natural enemies and trichomes can have direct negative impacts on biological control by decreasing natural enemy search efficiency. Manipulation of

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plant traits through plant breeding or bioengineering, as well as knowledge of the ecology and biology of herbivores and natural enemies, can work together to aid crop protection.

References Agrawal, A. A. 2000. Mechanisms, ecological

consequences and agricultural implications of

tri-trophic interactions. Current Opinion in Plant Biology. 3: 329-335.

Peterson, J.A., Ode, P.J., Hofman, C.O and Harwood, J.D. 2016. Integration of Plant Defense Traits with Biological Control of Arthropod Pests: Challenges and Opportunities. Front. in Plant Sci. 7: doi: 10.3389/fpls.2016.01794.

58. PLANT BREEDING AND GENETICS 14526

Linkage Disequilibrium Mapping as an Advancement in Crop Breeding

*Parmeshwar Kumar Sahu and Satyapal Singh

Department of Genetics and Plant Breeding, IGKV, Raipur- 492012 (Chhattisgarh) *Corresponding Author eMail: [email protected]

INTRODUCTION: Linkage disequilibrium refers to the non-random association of alleles between genetic loci on the same or different chromosome. It is also called as gametic phase disequilibrium. LD occurs when genotypes at the two loci are not independent of another. LD is the result of physical linkage of genes. LD could be the outcome of recent migration, recent selection, new mutation and increased by self-pollination, inbreeding, low recombination rate, genetic isolation between lineage, population admixture, population subdivision and epistasis. While factors like out-crossing, high recombination rate, high mutation rate and gene conversion leads to decrease or decay in linkage disequilibrium (Yu and Buckler, 2006; Vinod, K.K., 2011).

Association mapping or linkage disequilibrium mapping is a method of mapping quantitative trait loci (QTLs) using historical meiotic recombination events performed over several generations to link phenotypes (observable characteristics) with genotypes (genetic constitution) in large germplasm populations. It is a powerful genetic mapping tool for crops and provides high-resolution, broad allele coverage, and cost-effective gene tagging for the evaluation of plant germplasm resources.

Concept of Linkage Disequilibrium Mapping

Association mapping is based on the principle that over several generations of recombination, correlations of linked markers with trait of interest will remain. Therefore, spurious associations between genotype and trait may be detected due to the degree of structure within the population, necessitating development of various statistical methods to account for population structure (Balding, 2006; Vinod, K.K., 2011). Association mapping give surety of high resolution mapping by exploitation of historical recombination events at the population level that may enable gene level mapping on non-model organisms where linkage-based approaches would not be feasible. Potential exploit of such approach

could be for fine mapping of genes / QTLs, identifying favorable alleles for marker assisted selection and cross validation of outcome from linkage mapping for accurate position of genes / QTLs of interest (Rosyara and Joshi, 2012).

Genetic Mapping of QTLs

Genetic mapping of QTLs can be performed in two main ways: (1) Linkage analysis based mapping or conventional mapping using experimental populations or bi-parental mapping populations and (2) Linkage disequilibrium based mapping or “association mapping” using diverse lines from the natural populations or germplasm collections or landraces. Linkage based QTL mapping can identify the related genes to biparental variations so that mapping resolution depends on the number of recombinations occurred in the process of the development of mapping populations. Furthermore, construction of a suitable mapping population for study is very time consuming. Association mapping has recently become popular for identifying and mapping QTLs with high resolution. Linkage disequilibrium (LD) based association mapping can lead to the most effective utilization of ex-situ conserved natural genetic diversity or germplasm resources of crop plants.

Advantages of linkage disequilibrium mapping over conventional linkage mapping:

LD mapping has many major advantages over linkage analysis based QTL mapping

Much larger and more representative gene pool can be surveyed

Much higher resolution can be achieved

Greater number of allelic diversity can be analyzed

No need to generate bi-parental mapping population so research time will be less

It enables the mapping of many traits in one set of genotypes

Finally, it has the potential not only to identify and map QTLs but also to identify the causal polymorphism within a gene that is

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responsible for the difference in two alternative phenotypes (Rosyara and Joshi, 2012; Sehgal et al., 2016).

Unlike family-based linkage analysis, LD mapping does not require family or pedigree information and can be applied to a range of experimental and non-experimental populations.

Computer Softwares for Analysis

There are several free and paid softwares available for association mapping analysis. Some of them are as follows, TASSEL, STRUCTURE, EMMA, SAS, R, PLINK, BAPS, GenStat, JMP Genomics, FaST-LMM, GGT, MIDAS, SVS7 etc.

References Balding, D.J. 2006. A tutorial on statistical methods

for population association studies. Natural Genetics, 7: 781-791.

Rosyara, U.R. and Joshi, B.K. 2012. Association mapping for Improvement of Quantitative traits in Plant breeding population. Nepal journal of biotechnology, 2(1): 72-89.

Sehgal, D., Singh, R. and Rajpal, V.R. 2016. Quantitative trait loci mapping in plants: concepts and approaches. Molecular Breeding for Sustainable Crop Improvement Springer International Publishing Switzerland. Pp 31-59.

Vinod, K.K. 2011. Association mapping in crop plants. Advanced faculty training on “impact of genomics on crop improvement: perceived and achieved” TNAU, Coimbatore.

Yu, J. and Buckler, E.S. 2006. Genetic association mapping and genome organization of maize. Current Opinion in Biotechnology, 17:155–160.


Biofortification: A Tool to Combat Hidden Hunger of the Poor Asit Prasad Dash1 and Soumitra Mohanty2

1Ph.D. Research Scholar, Department of Plant Breeding and Genetics, OUAT, BBSR-3, Odisha 2Assistant Agriculture Officer, Department of Agriculture and Farmers’ Empowerment, Government of

Odisha *Corresponding Author eMail: [email protected]

INTRODUCTION: The Green Revolution that began in the 1940s and 50s brought about large increases in crop yields and saved millions of people from mass famine. Though it succeed to overcome the hunger of the huge population, it couldn’t show the same magic to combat the hidden hunger i.e. a condition of undernutrition, where the body lacks essential vitamins and minerals that keep people healthy. Yet malnutrition remains widely prevalent around the globe. While many people eat enough calories, many do not get enough nutrients. According to the Food and Agriculture Organization of the United Nations almost a third of the world’s population still do not get enough essential nutrients and suffer from hidden hunger. Deficiencies in micronutrients such as zinc, iron and vitamin A can cause profound and irreparable damage to the body— blindness, growth stunting, mental retardation, learning disabilities, low work capacity, and even premature death. Many rich countries fortify their foods with vitamins and micronutrients in order to overcome this situation. However poor countries do not have such facilities, as a result of which they become the victim of this hidden hunger.

Biofortification and its Importance

Biofortification or Biological fortification is the process of breeding nutritionally enhanced food crops that provides a comparatively cost-effective, sustainable, and long-term means of delivering more micronutrients. It differs from conventional fortification in that biofortification aims to

increase nutrient levels in crops during plant growth rather than through manual means during processing of the crops. Biofortification is more helpful for those poor populations, who suffer the most from the hidden hunger. From an economic point of view, it needs only one time investment.

Methods of Biofortification

Crops can be improved to produce higher levels of certain desired nutrients by manipulating their genetic makeups. This can be done through conventional plant breeding or genetic engineering.

a) Conventional breeding approach: Genetic variations in essential nutrient content are taken in consideration to improve the levels of minerals and vitamins in crops by conventional breeding programs. Using this method, plant breeders search seed or germplasm banks for existing varieties of crops which are naturally high in nutrients. Then they crossbreed these high-nutrient varieties with high-yielding varieties of crops, to provide a seed with high yields and increased nutritional value. This method is prevalent at present, as it is cheaper, and less controversial than genetically engineering crops. Harvest-Plus, An organization working on biofortification, is investing $14 million annually to boost three key nutrients—vitamin A, iron, and zinc in 12 target crops, relying almost exclusively on conventional breeding. However conventional breeding has disadvantage of limited genetic variation present in the gene pool which can be overcome by crossing to distant relatives and thus

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moving the trait slowly into the commercial cultivars.

b) Genetic Engineering Approach: With the advent of molecular biology, genes are characterized and utilized to engineer plant metabolism for biofortification. Genetic engineering is more precise and involves isolating individual genes from the wild relatives of a domesticated crop or other species that code for increased production of certain nutrients and transferring them into the plant. Pathways from bacteria and other organisms can also be introduced into crops to exploit alternative pathways for metabolic engineering. Thus, these technologies provide a powerful tool that is unconstrained by the gene pool of the host. It is also possible for different genes coding for increased levels of different nutrients to be “stacked” in a crop using genetic engineering methods, so that a crop can be biofortified with more than one desired nutrient. Though the possibilities associated with transgenic approaches keep plant biologists optimistic, regulatory hurdles associated with this technology make commercial applications difficult.

Golden Rice is an example of a genetically engineered crop developed for its nutritional value. The latest version of Golden Rice contains genes from a common soil bacterium Erwinia and maize, and contains increased levels of beta-carotene, which can be converted by the body into vitamin A. Other such examples are mentioned in Table-1.

TABLE 1: Schedule of product released

Crop Nutrient Countries of first release

Agronomic trait Release

yeara

Sweet potato

Pro-vitamin A

Uganda, Mozambique

Disease resistance, Drought tolerance, acid soil tolerance

2007

Bean Iron, Zinc

Rwanda, DR Congo

Virus resistance, Heat and drought tolerance

2010

Pearl Millet

Iron, Zinc

India Mildew resistance, Drought tolerance

2011

Cassava Pro-vitamin A

Nigeria, DR Congo

Disease resistance

2011-12

Maize Pro-vitamin A

Zambia Disease resistance, Drought tolerance

2011-12

Rice Zinc, Bangladesh, Disease and 2012-

Crop Nutrient Countries of first release

Agronomic trait Release

yeara

Iron India pest resistance, cold and submergence tolerance

13

Wheat Zinc, Iron

India, Pakistan

Disease resistance, Lodging

2012-13

a Approved for release by National Governments after intensive multi-location testing for agronomic and micronutrient performance Source: (Bouis et al., 2009)

Advantages

After the one-time investment to develop seeds that fortify themselves, recurrent costs are low, and germplasm can be shared internationally. This multiplier aspect of plant breeding across time and distance makes it cost- effective. Once in place, the biofortified crop system is highly sustainable. Nutritionally improved varieties will continue to be grown and consumed year after year, even if government attention and international funding for micronutrient issues fade. This provides a feasible means of reaching undernourished populations in relatively remote rural areas, delivering naturally fortified foods to people with limited access to commercially marketed fortified foods. Biofortified foods may also be useful for increasing micronutrient uptake in high-income countries. An example of this trend would be research into grain with higher levels of selenium, which, amongst other benefits, helps prevent prostate cancer.

Limitations

Lack of sufficient variation in the population for essential nutrient content is the major limitation in case of conventional breeding approach. Some people, while not opposed to biofortification itself, are critical of genetically modified foods, including biofortified ones such as golden rice. There may occasionally be difficulties in getting biofortified foods to be accepted if they have different characteristics to their unfortified counterparts. For example, vitamin A enhanced foods are often dark yellow or orange in colour. Some have criticized biofortification programs because they may encourage “further simplification of human diets and food systems”, because “biofortification is a strategy that aims to concentrate more nutrients in few staple foods.

References Bouis H. E., Hotz C., McClafferty B., Meenakshi J.V.

and Pfeiffer W. H. (2009) Biofortification: A New Tool to Reduce Micronutrient Malnutrition. 19th International Congress of Nutrition to be held in Bangkok, Thailand, October 4-9, 2009.

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Changes in Histone Dynamics at the Single-Cell Level Leads to Cell Differentiation and Development:

Arabidopsis as an Example 1*Prem Chand Gyani, 2Nitin Sharma, 3Mallik M., and 4Jitendra Meena

1Ph.D. Scholar, ICAR- Indian Agricultural Research Institute, New Delhi-110012 *Corresponding Author eMail: [email protected]

INTRODUCTION: The mechanism whereby the same genome can give rise to different cell types with different gene expression profiles is a fundamental problem in biology. Chromatin organization and dynamics have been shown to vary with altered gene expression in different cultured animal cell types, but there is little evidence yet from whole organisms linking chromatin dynamics with development. Here, the role of histone-DNA interactions in plant cell differentiation is investigated. It is demonstrated that cell differentiation is accompanied by global changes in histone-DNA interactions during Arabidopsis root development. Both fluorescence recovery after photobleaching and two-photon photoactivation is used to show that, as cells progress from meristematic to fully differentiated, core histones become less mobile and more strongly bound to chromatin. It is shown that these transitions are largely mediated by changes in histone acetylation. It is further shown that altering histone acetylation level, either in a mutant or by drug treatment, alters both the histone mobility and markers of development and differentiation.

The following is the brief description of the various objectives, along with the method, result and conclusion within each objectives:

To determine whether histone-DNA interactions change during meristem cell differentiation: The FRAP data for H2B-GFP showed that the half-time (t1/2) for recovery in the division zone was significantly less than that in the elongation or differentiation zones. Quantitative analysis of the FRAP data also showed that the size of the mobile H2B fraction was highest in the division zone and decreased successively in the elongation zone and the differentiation zone

To exclude the possibility that the observed differences in fluorescence recovery reflected differences in rates of protein synthesis – Method- Entire nuclei of cells expressing

H2B-GFP were photobleached and the recovery of the fluorescence signal, which had to be due to newly synthesized H2B-GFP proteins, was measured

– Result-synthesis rate observed for cells in the different zones was very small and comparable between the different zones

– Conclusion- different exchange kinetics of H2B-GFP in the different zones cannot be accounted for by differential de novo expression rates and must be due to differential histone exchange dynamics

To study whether general differences in protein mobility in the different cell types results in different mobilities of H2B-GF – Method- the mobility of a nonchromatin

binding protein of a similar size to H2B from the capsid of the virus MS2 (MS2CP-GFP) was analysed.

– Result- no differences in the FRAP curves for this protein within the different developmental zones

– Conclusion- general differences in protein mobility in the different cell types cannot explain the different mobilities of H2B-GFP

To determine whether the changes in dynamics were limited to H2B or are a general property of all core histones – Method- measured the exchange

dynamics of H2A and H4 using GFP fusion proteins to these histone

– Result- overall recovery kinetics were faster in the cells of the division zone

– Conclusion- it proves that it is the overall property of all histone proteins.

To eliminate the possibility that expressing histones with a non-native promoter might be affecting these results. – Method- behavior of the histone variant

H2A.Z-GFP (HTA11) under the control of its native promoter was analysed

– Confirmation- Same general trend was observed as with the other histones

– Conclusion- Same results with both canonical and noncanonical histones and using both heterologous and native promoters

Conclusion

Cell differentiation in the Arabidopsis root is accompanied by major changes in histone-DNA interactions.

This progression is at least in part regulated by histone acetylation

Thus chromatin organization may contribute to the maintenance of different states of

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development, therefore playing an important role in root development and differentiation

References Jamai, A., Imoberdorf, R.M., and Strubin, M. (2007).

Continuoushistone H2B and transcription-dependent histone H3 exchange in yeast cells outside of replication. Mol. Cell 25: 345–355.

Kimura, H., and Cook, P.R. (2001). Kinetics of core

histones in living human cells: little exchange of H3 and H4 and some rapid exchange of H2B. J. Cell Biol. 153: 1341–1353.

Kireeva, M.L., Walter, W., Tchernajenko, V., Bondarenko, V., Kashlev, M., and Studitsky, V.M. (2002). Nucleosome remodeling induced by RNA polymerase II: loss of the H2A/H2B dimer during transcription. Mol. Cell 9: 541–552.


Cisgenesis: A Technique for Crop Improvement 1Rameshraddy*, 1Manjugouda I. Patil, 1Shivalingappa Bangi and 2Kumar K P

1Department of Crop Physiology, UAS, GKVK, Bengaluru-65, 2Department of Entomology, UAS, GKVK, Bengaluru-65


The area of agricultural land used for production of transgenic (genetically modified, GM) crops has increased at an unprecedented speed since these crops were introduced 15 years ago. The cultivation area now amounts to 160 million hectares distributed among 29 countries worldwide. The first generation of GM crops primarily comprised soybean, maize, cotton and canola with tolerance to herbicides and insect larvae. Currently, so-called second-generation GM crop species with quality traits to enhance health benefits as well as drought tolerance and higher nitrogen use efficiency are in the process of being implemented (James, 2011). Although the introduced GM crops have been highly successful, it is apparent that only a fraction of the potential of genetic modification of crop plants is being realized. But the major concerns of the public about transgenic crops is the artificial combination of genetic elements derived from different organisms that cannot be crossed by natural means. This reservation is often linked to a notion of respect for nature and also appears to be interlinked with fears for potential health risks and for the spreading of new gene combinations in the environment.

With the aim to overcome the these problem and at the same time ensuring an environmentally sound and efficient plant production, the transformation concepts cisgenesis were developed as alternatives to transgenic crop development. The concepts are based on the exclusive use of genetic material from the same species or genetic material from closely related species capable of sexual hybridization. This is in contrast to transgenesis where genes and DNA sequences can be moved between any species. The gene pool exploited by cisgenesis is accordingly identical to the gene pool available for traditional breeding. Furthermore, foreign genes such as selection marker genes and vector-backbone genes should be absent or eliminated from the primary cisgenic transformants.

The Concept of cisgenesis was coined by

Schouten and colleagues (Schouten et al., 2006). They claimed that despite using the same genetic modification techniques as in transgenesis. Cisgenesis is the genetic modification of a recipient organism with a gene from a crossable sexually compatible organism (same species or closely related species). This gene includes its introns and is flanked by its native promoter and terminator in the normal sense orientation. The cisgenic plants could be compared to traditionally bred plants as the concept involves only genes from the plant itself or from a close relative. These genes could also be transferred by traditional breeding methods. The genomic region containing the gene of interest is left contiguous, including all regulatory elements.

Cisgenic plants can harbour one or more Cisgenes, but they do not contain any parts of transgenes or inserted foreign sequences. To produce Cisgenic plants any suitable technique used for production of transgenic organisms may be used. Genes must be isolated, cloned or synthesized and transferred back into a recipient where stably integrated and expressed.

Sometimes the term cisgenesis is also used to describe an Agrobacterium-mediated transfer of a gene from a crossable – sexually compatible – plant where T-DNA borders may remain in the resulting organism after transformation cisgenesis with T-DNA borders (EFSA, 2012).

The application of genome sequencing in crop plants like rice, maize, potato, and the development of efficient gene isolation techniques like map- based cloning and allele mining brought a new-fangled part of research in plant breeding by utilizing the cloned native genes (Jacobsen et al., 2008). During the last few decades, a variety of indigenous genes, coding for valuable traits like Insect, disease resistance and quality, from crop plants and their wild relatives have been isolated, characterized and introduced into the genetic background of elite germplasm. These native genes are isolated from the crop plant itself or from other cross compatible species, are referred

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as cisgenes to distinguish such group of genes from the transgenes (Schouten et al., 2006). In cisgenic approach as there is no introduction of new gene class from the cross incompatible species, hence the existing genetic variation indicate the one which are applied in conventional breeding programme which have been safely used since decades.

References EFSA., 2012, Scientific opinion addressing the safety

assessment of plants developed through cisgenesis and intragenesis. EFSA Journal, 10(2)

(2561):1-33. Jacobsen, E., Karaba, N., and Nataraja., 2008,

Cisgenics – Facilitating the second green revolution in India by improved traditional plant breeding. Current Science, 94(11): 1365-1366.

James, C., 2011, Global Status of Commercialized Biotech/GM Crops: 2011. ISAAA Brief 43. Ithaca, New York: ISAAA.

Schouten, H. J., Krens, F. A., Jacobsen, E., 2006, Cisgenic plants are similar to traditionally bred plants: international regulations for genetically modified organisms should be altered to exempt cisgenesis. EMBO Rep., 7: 750-753


Managing Genetic Diversity to Control Wheat Rust Ranjana Patial*1 and Neha Sharma2

Ph.D. Scholar1,2 Department of Crop Improvement, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur 176062

*Corresponding Author eMail: [email protected]*

Wheat (Triticum aestivum) is the second most important winter cereal in India after rice contributing substantially to the national food security by providing 21% of the food calories and 20% of the protein to more than 4.5 billion people in 94 developing countries (Braun HJ et al. 2010). Among the most important diseases in wheat that significantly reduce wheat production are those caused by the rusts viz., leaf, stem, and stripe rust. The rusts of wheat are among the most important plant widespread pathogens that can be found in most areas of the world where wheat is grown. Wheat leaf rust is caused by Puccinia triticina Eriks, wheat stem rust by Puccinia graminis f. sp. tritici, and wheat stripe rust by Puccinia striiformis f. sp. tritici. Yield losses caused by brown rust epidemic are estimated at around 40 per cent and losses due to black and yellow rust epidemics can be as great as 100 per cent. In recent years, new races of wheat leaf rusts, wheat stripe rust and wheat stem rust have been introduced into wheat growing areas in different continents. These introductions have complicated the efforts of breeders to develop wheat cultivars with durable resistance and have significantly reduced the number of the effective rust resistance genes available at present.

Until fairly recently, in many countries cereal crops consisted largely of landraces that were often mixtures of diverse genotypes. Even mixtures of crops such as wheat, oats, and barley were fairly common, and are still grown in some areas. This genetic diversity often provided protection against diseases. Host populations with low genetic diversity are predicted to have to higher infection prevalence and intensity of disease outbreaks than populations with greater diversity in host susceptibility. The effects of host genetic diversity on disease invasion was first

described in agriculture by Elton (1958), where crops grown in genetically homogeneous monocultures are typically more susceptible to severe disease outbreaks than mixtures.

Genetic diversity can be employed at three levels, intrafield, interfield, and interregion, to manage the evolution of a pathogen. The objective is not to eliminate the pathogen but to produce equilibrium between host and pathogen that results in little damage to the host and little change in the pathogen. One of several crop diversification strategies for disease control is to grow mixtures of plants that differ in their reaction to a pathogen (Finckh et al. 1998).

Here we are discussing the four different ways to manage wheat rust through genetic diversity viz., Multiline, mixtures, Interfield diversity and Deployment of genes for resistance. Browning (1974) has stated that “In the world of biology, diversity is the only protection against the unknown against a future risk situation”. It implies that precaution should be taken with regard to the extent of diversity without undue sacrifice of yield and quality.

Multiline approach offers a tremendous scope to rejuvenate and prolong the life period of some useful genotypes. The idea of multiline was put forward by Jensen in 1952 for use in cereals. Multiline variety is a mixture of several pure line of similar phenotype (height, seed color flowering time, maturity time and various other agronomic characteristics) but have different genes for the character under consideration the disease resistance

Development of Multiline Varieties

There are two main steps:

1. Development of component lines 2. Evaluation and grouping of the component

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lines.

1. Development of Component Lines- Has following Two Steps

i) Identification of several sources of distinct and preferably known genes for resistance to the concerned disease.

ii) ii. The resistance genes are incorporated in an elite variety or line to produce as many near isogenic lines as there are distinct R genes. This is done through a conventional backcross programme (5-6 backcrosses), a limited backcrossing (2-3backcross, followed by pedigree selection) or by making double or multiple crosses.

2. Evaluation and Grouping of Component Lines:

1. The component lines are first evaluated in multilocation trials for yielding ability, morphological features, agronomic features and productivity and for resistance to prevailing races at seedling and adult plant stage. Also, for resistance to other important prevailing disease.

2. The selected lines are then evaluated for compatibility. Mixing of two lines may have a positive, neutral or negative effect on their performance. Lines showing negative effect should be avoided.

3. The number of lines should be large 15-20 to obtain durable resistance. The seeds of lines should be mixed in equal proportion or on some other proportion e.g., in proportion to the agronomic performance of the lines, or the adult plant reaction to the line.

Merits of Multiline Varieties

1. All the lines are almost identical to the recurrent parent in agronomic characteristics, quality etc. Therefore, the disadvantage of the pureline mixture is not present in multiline varieties.

2. Only one or few lines of the mixture would become susceptible to the pathogen in any season. Therefore, the loss to the crop will be relatively low.

3. The disease spread will be reduced. 4. It reduces the risk of homogenizing the

pathogen population on a global scale. 5. Multiline varieties are more adaptive to

environmental changes than individual pure line

Demerits of Multiline

1. The seed of the multiline for cultivation has to be changed every few years depending on the change in the race of the pathogen.

2. Production and maintenance of line is cumbersome.

3. Multiline is based on a popular variety and is produced by backcrossing. Therefore, there potential performance remains the same as

that of the recurrent parent. By the time a multiline variety is developed, its recurrent parent may have already been replaced by the other superior variety.

Four multiline varieties have been released in wheat in India KSML3, MLKS 11, Bithoor (KML 7406) and SKAML-1, winter wheat multiline Tumult was released in Netherlands and Miramar was released in Cambodia.

Wolfe (1985) defined cultivar mixtures as "mixtures of cultivars that vary for many characters including disease resistance, but have sufficient similarity to be grown together." There are four mechanisms by which cultivar mixtures suppress disease viz., (a) Dilution effect (b) Barrier effect (c) Induced resistance (d) Modification of the microclimate.

Interfield diversity is attained by deploying resistance genes in different fields on a farm or larger area. This approach will be more successful if genes are deployed in a planned and controlled manner and if the pathogen’s virulence pattern is monitored (Parlevliet, 1981).

The high yielding, dwarf wheat varieties have become susceptible; hence there is an immediate need for incorporation of resistant genes into commercial varieties. Regional gene deployment implies that the use of resistance genes will be controlled by mutual consent among plant scientists or by some governing body. In India, leaf rust has become a major problem because of the breakdown of resistance in many semi-dwarf cultivars. Reddy and Rao (1979) proposed a system for deploying resistance genes and gene combinations in three areas of the country.

References Braun, H.J., Atlin, G., and Payne, T. (2010). “Multi-

location testing as a tool to identify plant response to global climate change,” in Climate change and Crop Production, ed. C. R. P. Reynolds (London: CABI).

Browning, J.A. (1974). Relevance of knowledge about natural ecosystems to development programmes for agro eco-systems Proc. Amer. Phytopath. Soc. 1:190-91

Elton, C.S. (1958). The ecology of invasions by animals and plants. John Wiley; New York, New York, USA

Finckh, M.R., Wolfe, M.S. (1998). Diversification strategies. In The Epidemiology of Plant Diseases, ed. DG Jones, pp. 231–59. London: Chapman & Hall

Jensen, N. F. (1952). Intra-varietal diversification in oat breeding. Agron. J. 44, 30-34

Parlevliet, J.E., (1981). Race-non-specific disease resistance. In: F.J. Jenkyn & R.T. Plumb (Eds.), Strategies for the Control of Cereal Disease, pp. 47–54. Blackwell Scientific Publications, Oxford

Reddy, M.S.S., and Rao, M.V. (1979). Resistance genes and their deployment for control of leaf rust of wheat. Indian J. Genet. Plant Breed. 39, 359–365

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Distant Hybridization: Barriers of Inter-specific and Intergeneric Hybridization

Ingle A. U.* and K. G. Kandarkar**

*PhD Scholar, **M.Sc.(Genetics and Plant Breeding), PGI, MPKV, Rahuri. *Corresponding Author eMail: [email protected]

Distant Hybridization

Hybridization crossing between two genetically dissimilar parents is called hybridization. Wide Hybridization Interspecific Hybridization:- Crosses made between distantly related species.

Intergeneric Hybridization:- Crosses made between distantly related genera. Somatic hybridization (Protoplast fusion). Crosses made between somatic cells Hybridization (recombination) is the third major evolutionary process with an importance not exceeding that of mutation and natural selection.

History: Thomas Fairchild (1717): The first authentic record of a distant hybridization for the crop improvement is the production of a hybrid between Carnation (Dianthus caryophyllus) and Sweet willian (Dianthus barbatus).

Karpechenko (1928): An interesting intergeneric hybrid, Raphanobrassica, was produced. Rimpu (1890): Produce the first intergeneric hybrid triticale which have greater potential than Raphanobrassica.

Introgressive Hybridization

Introgressive hybridization Transference of genetic material across an incompletely developed interspecific barrier, usually via a partially sterile F 1 hybrid, by means of repeated backcrossing and selection of well adopted backcross types, has been termed by Anderson and Hubricht (1938a) introgressive hybridization or introgression.

Inter-Specific Hybridization

Inter-specific hybridization: Ex. Nerica, an upland rice for Africa Oryza sativa (Asian upland rice): non-shattering, resistant to lodging, high yield potential Oryza glaberrima (African rice): drought tolerant, disease resistant, weed-suppressing Nerica rice combines the best of both species.

Triticale (Intergeneric Cross)

Triticale (intergeneric cross) Triticale, a new cereal created in the lab. Triticale, a cross (intergeneric cross) between wheat and rye, was produced by embryo rescue of the product of fertilization and a chemically induced doubling of the chromosomes. Embryo rescue becomes necessary when fertile offspring is never produced by an interspecific cross. Interspecific combinations of wheat and rye that produces hexaploid and octaploid triticales. Hexaploid triticale ABR genome Triticum taschii D genome

Triticum turgidum var. durum Durum wheat AB genome Seacle cereal Rye R genome Triticum aestivum common wheat ABD genome octaploid triticale ABDR genome.

Requirement of Distant Hybridization

Requirement of distant hybridization: Diseases and insect resistance Quality Wider adaptation Mode of reproduction yield Development of new varieties Production of new crop species (e.g.; Triticale hexaploid) Transfer of cytoplasm.

Difficulties Encountered in Interspecific Hybrids: Difficulties encountered in interspecific hybrids Failure of zygote formation Failure of zygote development Failure of F 1 seedling development.

Major Interspecific Crossability Barriers: Major interspecific crossability barriers I. Temporal and spatial isolation of species II. Pre-fertilization barriers on the surface of the stigma before pollen tube entry inside the tissues of the stigma and style inside the ovary and embryo sac III. Post fertilization barriers Non viability of hybrid embryos Failure of hybrid to flower Hybrid sterility Lack of recombinant Hybrid breakdown in F2 or later generation. I. Temporal and spatial isolation of parental species:

Non synchronous flowering of the parental species due to different agro-ecological or geographical background Early/staggered sowing Suitable photoperiodic treatment.

Pre-Fertilization Barriers

Unilateral incompatibility (UI) Prevent fertilization by arresting post pollination events at one or many levels Incompatibility operates in one direction, whereas the reciprocal cross is successful (unilateral incompatibility = UI) UI is more common when cross includes a selfcompatible (SC) and a self-incompatible (SI) The crosses show incompatible when an SI species is used as a female parent (SI x SC) Self-incompatibility inhibition is the result of active recognition of the pollen. Self-pollen is positively recognized as a result of the interaction of S allele product in the pollen and the pistil.


Active versus passive inhibition Self-incompatibility inhibition is the result of active recognition of the pollen. Self-pollen is positively recognized as a result of the interaction of S allele

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product in the pollen and the pistil Positive recognition results in the activation of metabolic processes in the pollen and/or the pistil to bring about pollen inhibition The arrest of post pollination events seems to be passive (not a result of active recognition of pollen) and a result of lack of co-adaptation between the pollen and the pistil It is like a “lock and key” mechanism (absent of suitable key(s) with the pollen for the lock(s) present in the pistil results in incompatibility. II. Pre-fertilization barriers:

Inhibition on the stigma surface Result in the arrest of pollen germination or pollen tube entry into the stigma One of frequent barriers, particularly in distantly related species The causative factors for the failure of pollen germination: Lack of effective adhesion Lack of full hydration Absence of pollen germination factors on the stigma Pollen adhesion and hydration are prerequisites for germination. II. Pre-fertilization barriers:

Pollen adhesion Largely depends on the nature and extent of the surface component of the pollen and the stigma It is not a constraint in species having wet stigma Pollen hydration The result of the transfer of water from the stigma to the pollen through an osmotic gradient Insufficient hydration may result in crosses in which the osmotic potential of the pollen does not match that of the stigma Rapid hydration that occurs on a wet stigma covered with aqueous exudates may lead to failure of pollen germination.


Inhibition in the stigma and style Failure of the pollen tube to reach the ovary is perhaps the most common interspecific pre-fertilization barrier Cause: The arrest of pollen tubes in the stigma Just below stigma Further down the style Arrested pollen tubes often show abnormalities in the form: Thicker tubes Excessive deposition of callose

Swollen tips Branching of tubes Growing pollen tubes utilize stylar nutrients. Arrested pollen tube growth is the inability of the pollen tubes to utilize stylar nutrient (Due to lack of suitable nutrient in the transmitting tissue or lack of suitable enzyme in the pollen tube.

Post-Fertilization Barriers

Result in the failure of fertilized ovules to develop into mature seeds More prevalent than pre-fertilization barriers May operate at different stages of embryo development or during germination and subsequent growth of the F1 hybrid Factors: Unbalance of ploidy levels Abnormalities in the embryo development The presence of lethal genes Genic disharmony in the embryo Failure or early breakdown of endosperm (no cell walls are formed; short lived, disappearing before seed is mature.

Post-Fertilization Barriers

Techniques to overcome: Removed of competing sinks Crosses are made using the first flowers to open on the maternal parent All immature fruits set on the maternal parent are removed before the cross is made Remove all other fruit from the vicinity of a fruit produce by wide crossing Pruning the maternal parent to remove all active growing point Reciprocal crosses Manipulation of ploidy level Embryo rescue Use of plant growth regulators.

Limitation of Distant Hybridization

Limitation of distant hybridization Incompatible crosses F 1 sterility Problems in creating new species Lack of homeology between chromosome of the parental species Undesirable linkage Problems in the transfer of recessive oligogenes and quantitative traits Lack of flowering in F 1 Problems in using improved varieties in distant hybridization Dormancy.

64. SEED SCIENCE AND TECHNOLOGY 13703

Hybrid Seed Production Technology Ashutosh S. Dhonde and Sunil D. Thorat

Ph.D. Scholar, Department of Agronomy Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra (413 704)

Classes of Quality Seeds

These different classes of seed have different requirements and serve different functions:

1. Breeder seed: It is the seed or the vegetative propagating material produced by the breeder who developed the particular variety. The production & maintenance of breeders stock on main research station is controlled by the plant breeder. It is produced by the institution where the variety was developed in case the

breeder who developed the variety is not available. In India, it is also produced by other Agri. Universities under the direct supervision of the breeder of the concerned crop working in that University, this arrangement is made in view of the large quantities of the breeder seed required every year. It is generally pure having high genetic purity (100%). Off type plants are promptly eliminated and care is taken to prevent out crossing or natural hybridization & mechanical mixtures.

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2. Foundation seed: It is the progeny of the breeder seed and is used to produce registered seed or certified seed. It is obtained from breeder seed by direct increase. It is genetically pure and is the source of registered and/or certified seed. Production of foundation seed is the responsibility of NSC. It is produced on Govt. farms (TSF), at expt. stations, by Agri. Universities or by component seed growers under strict supervision of experts from NSC. It should be produced in the area of adaptation of the concerned variety.

3. Registered seed: It is produced from foundation seed or from registered seed. It is genetically pure & is used to produce certified seed or registered seed. It is usually produced by progressive farmers according to technical advice and supervision provided by NSC. In India, often registered seed is omitted and certified seed is produced directly from foundation seed.

4. Certified seed: It is produced from foundation, registered or certified seed. This is so known because it is certified by a seed certification agency, in this case state seed certification agency, to be suitable for raising a good crop. The certified seed is annually produced by progressive farmers according to standard seed production practices. To be certified, the seed must meet the prescribed requirements regarding purity & quality. It is available for general distribution to farmers for commercial crop production.

Steps involved for Quality Seed Production in Hybrid

1. Parental lines for some of the hybrids 2. Selecting the right season 3. Seed rate 4. Pre-sowing seed treatment 5. Isolation distance 6. Planting ratio- Spacing 7. Border rows 8. Fertilizer application 9. Rouging 10. Staggered sowing 11. Irrigation management 12. Weed control 13. Plant protection 14. Harvesting and Threshing 15. Drying 16. Seed Processing 17. Packing and Storage 18. Seed certification -Field standard

Seed Multiplication Ratio

Generation System of Seed Multiplication: Generation system of seed multiplication is

nothing but the production of a particular class of seed from specific class of seed up to certified seed stage. The choice of a proper seed multiplication model is the key to further success of a seed programme which basically depends upon,

a) The rate of genetic deterioration b) Seed multiplication ratio and c) Total seed demand

Based on these factors different seed multiplication models may be derived for each crop and the seed multiplication agency should decide how quickly the farmers can be supplied with the seed of newly released varieties, after the nucleus seed stock has been handed over to the concerned agency, so that it may replace the old varieties.

In view of the basic factors, the chain of seed multiplication models could be,

a) Three Generation model: Breeder seed - Foundation seed - Certified seed

b) Four - Generation model: Breeder seed-Foundation seed (I) Foundation seed (II) – Certified seed

c) Five - Generation model: Breeder seed - Foundation seed (I)- Foundation seed (II) - Certified seed (I) - Certified seed (II)

Seed Multiplication Ratio

It is nothing but the number of seeds to be produced from a single seed when it is sown and harvested. According to expert group of seeds (1989), the seed multiplication ratio for different crops are as follows.

Crop Seed Multiplication Ratio

Wheat 1:20

Paddy 1:80 (Varieties)

1:100 (Hybrids)

Maize 1:80 (Varieties)

1:100 (Hybrids)

Sorghum 1:100

Bajra 1:200

Ragi 1:80

Gram 1:10

Blackgram 1:40

Greengram 1:40

Cowpea 1:40

Horsegram 1:40

Moth bean 1:40

Red gram 1:100

Cole crops 1: 433

Potato 1:4

Groundnut 1:8

Visit us at: agrobiosindia.com

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65. SEED SCIENCE 13915

Workout of Seed Treating Equipment’s Dr Pankaj P Jibhakate

Senior Technical Asst. AICRIP BSP Seed Testing Laboratory, Dr. Balasaheb Sawant Kokan Krishi Vidyapeeth, Dapoli. Maharashtra-415712


Commercial seed treaters are designed to apply accurately measured quantities of pesticides to a given weight of seed.

1. Dust Treater (Gustafson XL Dry Powder Seed Treater)

Controlling the Flow of Seed: The amount of seed which flows into the weigh pan (which is just beneath the feed hopper on top of the treater) is controlled by opening or closing the gates of the feed hopper by means of the hand wheel on the side of the hopper. The scale on the hopper shows how far the gates are open (in inches). Gates should be open to whatever number of inches it takes to keep the weigh pan filled to the required number of pounds per dump as it tilts in either direction. The number of pounds per dump is adjusted by correctly setting the counterweight up or down on the counterweight arm.

Powder Application: To be sure that the correct amount of powder is being applied to the seed flow, a preliminary test must be made in which a given number of pounds of seed (such as 100 lbs) is run through the feeder. During this run, the measuring cup provided with the feeder should be used to catch the powder as it comes off the vibrator. After the given amount of seed has run through, the powder should be weighed in order to determine how much is being applied to that amount of seed. The vibrator speed can then be adjusted accordingly. Then a second or more tests should be run until proper setting of the vibrator speed is determined for correct coverage.

Approximate Setting

No. Dumps

Powder Scale Opening

Syntron Setting

Oz. Produced/100 lbs.

25 1/2 60 2

25 3/4 60 5

25 3/4 70 6

25 3/4 80 7

25 1 60 10

Number 4 on counterweight arm gives five pounds per dump.

2. Slurry Seed Treater

The slurry treatment principle involves suspension of wettable powder treatment material in water. The treatment material applied as a slurry is accurately metered through a simple mechanism composed of a slurry cup and seed dump pan. The cup introduces a given amount of slurry with each

dump of seed into a mixing chamber where they are blended.

While operation of the slurry treater is relatively simple, the various operation procedures must be thoroughly understood.

1. The metering principle is the same in direct, ready-mix or fully automatic treaters i.e., the introduction of a fixed amount of slurry to a given weight of seed.

2. To obtain a given dump weight, slurry treaters are equipped with a seed gate that controls seed flow to the dump pan. With the proper seed gate setting, a constant dump weight for a given can be obtained.

3. The amount of treatment material applied is adjusted by the slurry concentration and the size of the slurry cup or bucket. As the dump pan fills, a point is reached where it over-balances the counter weight and dumps into the mixing chamber. This brings the alternate weighing pan in position to receive the inflow of seed and activates a mechanism to add a cup of slurry to the mixing chamber. Thus, one cup of slurry is added with each dump of seed.

4. The mixing chamber is fitted with an auger type agitator that mixes and moves seed to the bagging end of the chamber. The speed of the auger is important, because at slow speeds more uniform distribution is obtained.

Slurry tanks have 15 to 35 gallon capacities, depending upon the size of the treater. They are equipped with agitators that mix the slurry in the tank and keep it suspended during operation. It is important that the powder be thoroughly suspended in water before treating. If the treater has been idle for any period of time, sediment in the bottom of the slurry cups must be cleaned out. The proper size slurry cup must be used. Most machines now have cups with ports and rubber plugs for 15 cc, 23 cc, and 46 cc quantities. Some users prefer to mix the slurry in an auxiliary tank and then transfer to the slurry chamber as needed.

Direct Treaters: Direct treaters are the most recent development and include the Panogen and Mist-O-Matic treaters. These two were initially designed to apply undiluted liquid treatment. Instead of applying 23 cc of material per 10 pounds of wheat, as in slurry treaters, they apply 14 to 21 cc (1/2 to 3/4 ounces) per bushel of "wheat. This small quantity of material is suitable only with liquid materials which are somewhat

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volatile and do not require complete, uniform coverage for effective action.

3. Panogen Seed Treater

The operation of the Panogen treater is relatively simple. A small treatment cup, operating from a rocker arm directly off the seed dump pan and out of a small reservoir, meters one cup of treatment with each dump of the seed pan. Fungicide flows through a tube to the head of the revolving drum seed mixing chamber. It flows in with seed from the dumping pan and is distributed over the seed by the rubbing action of the seed passing through the revolving drum. The desired treating rate is obtained by the size of the treatment cup and by adjusting the seed dump weight. Treatment cup sizes are designated by treating rate in ounces and not by actual size-e.g., the 3/4 ounce cup applies 3/4 ounce (22.5 cc) of treatment per bushel with six dumps per bushel. The actual size of this cup is approximately 3.75cc.

4. Mist-O-Matic Seed Treater

The "mist-o-matic" treater applies treatment as a

mist directly to the seed. The metering operation of the treatment cups and seed dump is similar to that of the "Panogen" treater. Cup sizes are designated by the number of cc's they actually deliver-e.g., 2 ½, 5, 10, 20 and 40. The treater is equipped with a large treatment tank, a pump and a return that maintains the level in the small reservoir from which the treatment cups are fed. After metering, the treatment material flows to a rapidly revolving, fluted disc mounted under a seed-spreading cone. The disc breaks droplets of the treatment solution into a fine mist and sprays it outward to coat seed falling over the cone through the treating chamber. Just below the seed dump are two adjustable retarders designed to give a continuous flow of seed over the cone between seed dumps. This is important since there is a continuous misting of material from the revolving disc. The desired treating rate is obtained through selection of treatment cup size and proper adjustment of the seed dump weight.


Tetra Zolium Test Chaudhary, V. P.

SRF, Pearl Millet Breeding, ICRISAT, Patancheru – 502 324, T.S. *Corresponding Author eMail: [email protected]

The vital component of the world’s diet is seed and the best potential of any seed is judged by its germination percent. Germination incorporates those events that commence with the uptake of water by the quiescent dry seed and terminate with the elongation of the embryonic axis (Bewley and Black, 1994). To estimate the quick germinability of any seed a test commonly used is the Tetra Zolium (TZ) test which is useful in processing, handling, storing and marketing large quantities of seed in a short time, testing dormant seed lots, vigour rating of the seed lots, supplementing germination test results and diagnosing the cause of seed deterioration.

The TZ test is reliable and widely utilized which was pioneered by the German scientist Lakon during the mid-nineteens (1939-1958), who recognised that all living tissues, which respire, are capable of reducing a colourless chemical 2,3,5 triphenyl tetrazolium chloride or bromide into a red coloured compound formazen. The chemical used for this test is a cream or light yellow coloured water soluble powder called 2,3,5,- triphenyl tctrazolium chloride. The TZ test was successfully accepted and used in several other countries. The test was introduced in Brazil by several seed technologists that were trained at Mississippi State University. Moore (1973) described the use of TZ staining more efficiently

on the basis of the topographic pattern of the seed. When triphenyl-formazan is formed in the

seed tissue, it means that there is respiratory activity in the mitochondria in the cells of the seed tissue, which is concluded to be alive. Therefore, the resulting red color in the seed tissue is a positive indicator of its viability, by indirectly detecting respiratory activity at the cellular level. Non-viable seed tissues do not react with TTC (2, 3, 5-triphenyl tetrazolium chloride - TTC), and consequently do not stain. lf the tissue is vigorous, a normal faint red color will result; if it is weak, an intensive red will develop, due to an intensive diffusion rate of the TTC solution through the damaged cell membranes of the seed tissue; if it is dead, no reduction will occur, and the dead tissue will contrast as white (non-colored) with the stained living tissue. These color differences, together with the knowledge of several seed feature s, permit an assessment of the presence, location, and nature of disturbances within embryo tissues (Moore, 1973).

Listed below are the major advantages of the tz-test:

a) it by-passes major environmental disturbances that might affect the performance of growth tests;

b) focuses attention on the physical and physiological conditions of the embryo

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structures of each individual seed; c) provides quick evaluation: 8 hrs for soybean; d) allows identification of the leveI of seed vigor; e) diagnoses the causes of seed deterioration; f) requires only simple and inexpensive

equipment. g) an experienced analyst may analyze between

four to five seed samples (2 X 50 seeds) per hour.

Disadvantages of TZ Test

a) it requires knowledge of the seed structures and interpretation techniques;

b) is relatively tedious, because examination of individual seeds requires patience and experience;

c) consumes more time per sample than the standard germination test in spite of being a quick test; however, the TZ test provides more information than the standard germination test;

d) does not show the efficacy of chemical seed treatments nor the damages that they may cause;

e) requires from the analyst a decision making capability, due to the characteristics of the test.

Mason et al. (1982) reported that the TZ test was not effective in detecting recently induced mechanical damage. This problem can be easily overcome with the use of lower concentrations

(0.075%) of the TZ solution.

Tetrazolium Test for Vigour Assessment

After differentiating viable seeds from the non-viable ones, the viable seed group can be reclassified into several vigour groups on the basis of intensity of stain and staining pattern of different seed parts. The simplest classification is to divide viable seeds lot having larger number of sound seeds will be considered more vigorous. A better estimate of vigour can be obtained by colorimetric determination of formazan. Kittock and Law (1968) described a method of estimating seed vigour on the basis of colour intensity of the stained embryo or seed.

References Bewley, J.D., and Black, M. (1994). Seeds: Physiology

of Development and Germination. (New York: Plenum Press).

Kittock, D.L. and Law, A.G. (1968. Relationship of seedling vigour to respiration and tetrazolium chloride reaction of germinating wheat seeds. Agronomy Journal 60: 286-288.

Manson, S.C., Vorst, J.J., Hankins, B.J., Holt, D.A. (1982). Standard, cold, and tetrazolium germination tests as estimators of field emergence of mechanically damaged soybean seed. Agronomy Journal, 74, p.546-550, 1982.

Moore, R.P. (1973). Tetrazolium staining for assessing seed quality. In: Heydecker, W. ed. Seed ecology. London: Butterworth, p. 347-366.


Demand Forecast for Seed Production and Seed Marketing Structure

Himaj S. Deshmukh

Ph.D. Scholar, Dept. of Agril. Botany, MPKV, Rahuri (M.S.) *Corresponding Author eMail: [email protected]

What is Seed Marketing?

Seed marketing is an important component of seed industry. Seed marketing includes, acquisition and selling of packed seeds, intermediate storage, delivery and sales promotional activities.

Demand Forecast

Assessment of effective seed requirement is very important for planned agricultural production. The supply of seeds, of the variety in demand, must keep pace with the seed requirement of desired quality, at the place and time of requirement and at an optimum price. The plan for seed production distribution is prepared by the Ministry of Agriculture, Government of India, with the co-operation of the State Governments. The State Agriculture Departments make assessments regarding the seed demand and the plant breeders make the plans for foundation seed production for

different varieties. Statistical techniques (Time series analysis and Regression analysis) are used for assessing the long-term demands.

The following factors are considered in making demand forecasts:

a) Total cultivated acreage, seed rate, seed replacement period and assessment of total potential seed requirements, of each of the important crops.

b) Impact of extension efforts on the introduction of improved production techniques and future plans for promotion.

c) Current acreage under high yielding varieties and amount of seed sold in the preceding year.

d) Cultivators preferences for varieties, packet size, kind of packing, quality and price of seeds.

e) Number and size of competitors. f) Most effective media of publicity and sales

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promotion.

For calculating the expected demand of the seed of any crop, gross requirement is computed by multiplying the total cultivated area under the crop and the seed rate and by dividing it with the replacement period, net annual requirement of the seeds can be obtained. The estimation of the market demand of hybrid seeds is simpler than the self-pollinated crops, as these seeds have to be changed every year. In areas, where seed production is easy and the price of the crop is low, the farmers do not replace the seeds easily in comparison to the deficiency areas. Seed demand depends upon the price and quality of the seed. If the difference between the price of seed and commercial crop is low, the market demand of the seed is more, but the demand is decreased on increasing this difference. Salesmen, extension workers and agriculture development agencies, play important role in popularizing the seed of high yielding varieties among the farmers.

Seed Marketing Structure

Success of seed marketing depends on the establishment of effective seed distribution system. Various systems of seed distribution are prevalent in the country.

Farmer to farmer distribution: This is the traditional method, whereby farmers obtain the seed of their requirements from their neighbors, either on cash payment or on exchange basis. No formal marketing organization is required for this type of distribution.

Distribution by registered growers: Several State Governments make the seeds available to the registered growers and they are expected to distribute the seeds to farmers on cash payment or on exchange basis.

Distribution by Co-operatives: The co-operative societies supply the seeds to the

farmers, directly or on sawai (return), basis, which is often encouraged by the Government through subsidies and guarantees.

Distribution by Departments of Agriculture: In this system as seeds are purchased by the government and are distributed among die fanners through district Agriculture Officers and Block Development Officers.

Distribution by quasi-government and non-government agencies: These seeds are distributed through a network of seed distributors and seed dealers.

The Seed Review Team (1968) and the National Commission on Agriculture (1976) have recommended that N.S.C. and other seed corporations should establish a network of seed distribution throughout the country in which the wholesale dealers and retailers are included.

The simplest and most efficient system is to establish a central marketing cell, distributing seeds to several channels through its regional offices in the end-use areas, which should have minimum processing art storage facilities and should function as wholesale units.

The Detail sale could be organized by appointing distributors/dealers, which could be private dealers, cooperatives or agro-sale service centers, etc.

The central marketing cell would be responsible for acquisition, processing, packaging and storage of seeds, until it is handed over to retailers.

It will also be responsible for appointment of dealers/distributers, sales promotion and seed pricing.

The regional offices are responsible for supply of seeds and promotional materials to dealers, training of seed dealers and publicity and execution of promotional programmes.


Methods to Break the Dormancy Arun Rathod1* and Subhalaxmi2 Roy2

Department of Agricultural Entomology, BCKV-741252, West Bengal, INDIA 2Department of Agricultural Entomology OUAT Bhubneshwar-751003, (Odisha), INDIA


A. What is Seed Dormancy?

A physical or physiological condition of viable seed, which prevents germination even in the presence of favorable conditions.

Types of Seed Dormancy

1. Exogenous dormancy: The major type of exogenous dormancy is called physical dormancy and these are often called hard seeds. Physical dormancy is caused by the

outer seed coverings preventing the seed from taking up water. In nature, physical dormancy is most often satisfied by exposing the seed to high temperature conditions.

2. Endogenous dormancy: Physiological and morphophysiological are the two major types of endogenous dormancy found in tree species.

3. Morphological dormancy is a third type of endogenous dormancy, but it is most often

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seen in herbaceous plants. Seeds with physiological dormancy require a period of moist, chilling to satisfy dormancy.

B. Causes of Seed Dormancy

1. Seed coat factor: Hard seed coat – These are impermeable to water, gases so restrict water uptake and oxygen exchange.

2. Embryo factor: Immature embryo – Seeds with small and undeveloped embryos do not germinate.

3. Inhibitory factors: Germination inhibitors – Seeds contain some chemical plant growth regulators, which inhibit seed germination.

4. Period after ripening: Some seeds have a period of ripening. Those seed germinate only after the completion of this period.

C. Methods to Break the Dormancy

Scarification: Any process designed to make the seed coat more permeable to water and gases and thus more likely to germinate is known as scarification.

1. Natural breaking of dormancy: In nature dormancy terminates when embryo gets suitable environment such as adequate moisture, aeration and temperature.

2. Artificial Breaking of dormancy a) White Light: Exposure promotes this

process. Its other examples are seeds of tobacco, tomato, Betula and Digitalis. Such seeds respond to a light only after imbibing 30-40% moisture. Light is ineffective in the dry condition.

b) Exposure to red and far red lights: The exposure to very low intensity of light for short duration of 1-2 minutes is sufficient to overcome dormancy. The red part of white light of wavelength of 660u is very effective for germination.

c) Use of– plant hormones: The application of the hormones, gibberellic acid and

kinetin can replace the red light requirement or germination of lettuce seeds. Therefore, seeds can germinate in the presence of these hormones in the total darkness.

d) Stratification: The dormancy of chilling required seed is broken by stratification. Low temperature requirement given to the seeds to break their dormancy is called stratification. Dry seeds cannot be stratified. A minimum amount of moisture is required. Therefore, such seeds are allowed to imbibe water. Then they are exposed to low temperature.

e) Use of growth promoting substances for breaking seed dormancy: Certain chemicals promote the seed growth. Potassium nitrate, thiourea and ethylene ehlorhydrin are the most commonly used germination promoters. Similarly, the application of some of the plant hormones like gibberellic acid, cytokinin and ethylene also promotes.

Double Dormancy

Double dormancy is defined as a condition where seeds need to overcome two or more primary dormancies in order to germinate. Seed that needs to have the seed coat damaged so water can be absorbed, and then it needs a cold period before radicle growth.

Advantages of Seed Dormancy

1. Plant embryo survives during adverse conditions of weather, which are not favorable for growth (like winter).

2. Creation of a seed bank 3. Seed dormancy allows more time for

widespread seed dispersal 4. In some cases of dormancy one year’s seeds

do not germinate the same year, this improves species survival.

69. SEED SCIENCE14645

Technology for Seed Treatment Aradhana Dhruw, Omesh Thakur and Vivek Kurrey

Ph.D. Scholar, IGKV Raipur (C.G.) *Corresponding Author eMail: [email protected]

Seed Hardening

"Hardening" of seeds has been defined by Heydecker (1973) as, "a treatment preliminary to sowing during which seeds are moistened and dried back (once or a number of times) to activate certain physiological mechanisms which will enable the resulting plants to withstand adverse environmental conditions." The similar process of “advancing" has the restricted aim of enabling seed to pass through the first stages of

germination, short of radicle emergence, before the seed is sown.

Method of Seed Hardening

Seeds are soaked in water and allowed to absorb moisture up to 30 – 35 percent of their weight and kept in swollen condition for 1-12 h depend upon the crop species at 250C. These are then spread out in thin layer for drying in shade for 2 to 3 days. During this period, the seed gets dried almost to the original weight. This treatment is

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repeated 3 or 4 times depending upon kind and variety in crops. This treatment is not followed for proteinaceous seeds. Because these seeds are more hydrophilic in nature. It absorbs more water i.e. 4 to 5 folds which lead to internal damages to membrane system. However, preconditioning of seeds between moist gunny bags for shorter initial period, reduce the rate of imbibitions and also damage to seeds.

Chemicals used for Hardening

Hardening is done with water or with various chemicals to improve the physiological quality of seeds. Recently botanicals are also used.

1. Water (Hydro-hardened): 2. Salts: Sodium chloride, Sodium sulphate,

potassium nitrate, calcium chloride Ammonium sulphate, potassium chloride (Chemical hardening)

3. Growth Regulator: Gibberellic acid, Kinetin, CCC, Ascorbic acid, Succinic acid

4. Vitamins: Vitamin K3, Nicotinic acid, Pantothanic acid

5. Plant products: Garlic extract, coconut water, leaf extract of Pongamia pinnata, Albizia amara and Prosopis juliflora (Biological hardening)

Recommended Hardening Chemical for Pulses

Red gram & Blackgram 100 ppm zinc sulphate

Greengram 100 ppm Manganese sulphate

Bengal gram 1% Potassium dihydrogen phosphate

Anatomical and Morphological Changes

Hardened plants have more xeromorphic morphology than unhardened ones

More extensive and denser network of veins and ribs

Epidermal and stomata cells are smaller

Foliage area is increased

Faster recovery from atmospheric drought

Greater total and absorbing surface in the root system, as well as more number of primary roots.

Leaves of hardened plants have more of starch

Physiological and Metabolic Changes

Higher viscosity and elasticity of protoplasm

Increase in the physiological activity of the embryo and associated structures

Increase in photosynthetic activity

More intensive respiration

Higher mitochondrial activity

Increase in water balance of plants

High level of synthetic reactions even during drought, leaves of hardened plant have more starch

Formation of more high energy compounds

Increased DNA in the growing points

Active protein synthesis

Pre-enlargement of embryo

Advancement of germination

During seed hydration- bio-organelles activated

Advantages of Seed Hardening

Accelerate rapid germination and growth rate of seedling

Plants from the treated seeds recover quickly from wilting when compared to plants from untreated seeds

Flowering is slightly accelerated in treated plants

Induces resistance to drought and salinity

Seeds also withstand higher temperature (80-105 0C) for prolonged periods (24-48 hrs) without loss of viability

By emerging early, seedlings will be able to compete more effectively with weeds

Treated plants are generally better in growth and yield.

Seed Priming

Seed priming is defined as a pre-sowing treatment in which seeds are soaked in osmatic solution that allows them to imbibe water and go through the first stages of germination, but does not permit radicle protrusion through the seed coat. The seeds can be dried to their original moisture content and stored or planted via conventional techniques. Heydecker (1973) used different terms depending upon the methods adopted for the treatment such as:

i) Osmopriming – Soaking the seeds in osmotic solution

ii) Solid matric priming – Use of solid matric as a carrier agent for osmotic solution.

iii) Halopriming – Soaking the seeds in salt solutions.

iv) Biopriming – Coating the seeds with biological agents like bacteria.

Advantages of Seed Priming

Faster emergence and more uniform field stand in normal as well as in stress situations.

Beside uniformity, significant yield increase in many vegetable crops in particularly

Osmo-priming would very effective overcome the serious problem of soaking injury in many legume.

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Osmo-priming seeds can be rinsed and carefully dried for re-storage for short periods.

Limitations of Seed Priming

Osmotic seed treatment is expensive, especially when osmotic such as PEG are used. Only low volume, high value seeds are suitable for this treatment.

As the treatment is done over a long period, proper caution against microbial attack should be taken.

The bathing solution needs continuous aeration; otherwise the seed will suffer from the ill effects of anaerobic respiration.

In certain materials, there is a possibility of induction of secondary dormancy, particularly under unfavorable temperature and light

conditions.

Conclusion: Priming in botany and agriculture is a form of seed planting preparation in which the seeds are pre-soaked before planting. Priming is not an extremely widely used method. In general, most kinds of seeds experimented with so far have shown an overall advantage over seeds that are not primed. Many have shown a faster emergence time (the time it takes for seeds to rise above the surface of the soil), a higher emergence rate (the number of seeds that make it to the surface), and better growth, suggesting that the head-start helps them get a good root system down early and grow faster. This method can be useful to farmers because it saves them the money and time spent for fertilizers, re-seeding, and weak plants.

70. PLANT PATHOLOGY 14417

Sheath Blight of Rice: Disease and Management Renu, Hradesh Kumar, Upasana Sahu and Khan Mohd. Sarim

ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Maunath Bhanjan 275 101, India

Rice sheath blight (ShB) is an increasing concern for rice production especially in intensified production systems. It is a fungal disease caused by Rhizoctonia solani Kuhn (Teleomorph: Thanatephorus cucumeris (Frank) Donk). The disease causes significant yield loss and quality degradation worldwide.

Economic Importance of Sheath Blight

Rice ShB disease causes 10-30% yield loss and may reach up to 50% during prevalent years. In China only, about 15 to 20 million ha of rice growing area is affected, causing losses of 6 million tons of grains per year. Planting ShB susceptible rice varieties in the U.S. resulted in yield losses of about 50% in trial plots. In Arkansas, ShB was found present in 50-66% of rice fields, causing 5-15% yield losses in 2001. In Japan, the disease caused a yield loss of as high as 20% and affected about 120,000-190,000 hectares. A yield loss of 25% was reported if the flag leaves are infected. Studies at IRRI showed that sheath blight causes a yield loss of 6% in tropical Asia.

Causal Organism and Disease Symptoms

Rhizoctonia solani is a universal soil saprotrophic and facultative plant parasite and survives (for upto 2 years) in unfavorable conditions by forming sclerotia or dormant mycelia. Sclerotia are spread during field preparation and flooding the field for irrigation. Sclerotia or hyphae attach to the plant, infecting and causing ShB disease, and the pathogen spreads under conditions favourable to disease development. Initial symptoms occur on leaf sheaths near the water line as water-soaked

lesions when plants are in the late tillering or early internode elongation stage (approximately 10 – 15 days after flooding) varies from place to place. These lesions usually develop just below the leaf collar as oval-to-elliptical, green-grey, water-soaked spots about ¼ inch wide and ½ to 1 ¼ inch long. Disease development progresses very rapidly in the early heading and grain filling stages during periods of frequent rainfall and overcast skies. As plants senesce from maturity, lesions will dry and become greyish-white to tan with brownish borders. Sclerotia, initially white turning dark brown at maturity, are produced superficially on or near the lesions. Sclerotia are loosely attached and easily dislodge from the plant. Secondary infections are caused by hyphae growing upward towards uninfected plant parts, producing additional lesions and sclerotia on leaf sheaths to complete the disease cycle.

Visible plant disease symptoms include formation of lesions, plant lodging, and presence of empty grains. Disease spread and intensity is dependent on the amount of infectious inoculum present in planting material and residues of previous crop remaining in the field or in the top soil where rice is grown. Other impact factors for ShB disease severity are rice development stage at infection, ecological surroundings, cultivar resistance, and cultural and seasonal crop practices.

Predisposing Factors of Sheath Blight

Many factors play important role in infection of ShB. Relative humidity and temperature are the critical factors. The pathogen thrives when the

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humidity is around 96 % in the crop canopy. High infection occurs at 100 % relative humidity and gradually falls when it is decreased. High temperature (28 – 320C) and frequent rainfall favours disease development.

Disease Management

A range of ShB disease control measures have been reported in the literature.

Resistant Cultivars: To date, resistance breeding efforts against ShB has been only moderately successful, mainly due to a lack of source for resistance in cultivated rice or in wild related species. Nevertheless, rice cultivars ranging from susceptible to moderately resistant to ShB are available for cultivation. The development of new resistant cultivars was hampered through direct screening of germplasm because the fungal pathogen R. solani is plurivorous and semisaprobiotic.

Chemical Control: Current lack of effective resistant cultivars has led growers to rely increasingly on chemical fungicides for combating

rice ShB infection. Both systemic and non-systemic fungicides are available. Some of them are a Spray of either validamycin 3 L @ 2.5 ml or Hexaconazole 5 EC @ 2.0 ml or Thifluzamide 24 SC @ 0.75 ml or Propiconazole 25 EC @ 1 ml or Thiophanate-methyl 70 WP or Carbendazim 50 WP @ 1.0 g / L of water will prevent the spread of the disease.

Cultural Practices: To minimize sheath blight management practices must be integrated like reducing seeding rate or providing wider plant spacing to improve canopy architecture. Closer plant spacing should be avoided; otherwise it develops a dense crop growth favourable for the horizontal spread of the disease. Removal of weeds, helps to control sheath blight because the pathogen also attacks weeds which are commonly found in rice fields. Use reasoned level of fertilizer i.e. need-based or real-time or split application of nitrogen fertilizer is recommended in the fields with a high amount of inoculum. Draining rice fields relatively early in the cropping season to reduce sheath blight epidemics.


Integrated Management of Major Diseases of Chickpea *Kalpana Gairola, Pooja Upadhayay and Akansha Singh

Department of Plant Pathology, GBPUA&T, Pantnagar-263145, Uttarakhand, India. *Corresponding Author eMail: [email protected]

India is considered the largest producers of chickpea accounts almost 64% production worldwide. Chickpea occupies 38 % area under pulses and 50 % it contributes to the total pulse production in India. Chickpea contains protein (20-22%), carbohydrates (61.5 %), fat (4-5%), fiber, minerals (calcium, iron, and niacin), β- carotene in addition to this it also fixes the atmospheric nitrogen and has medicinal value as purifies the blood. Thus, it reduces the need for nitrogenous fertilizers. It is also used for human consumption and for a feeding of animals. Chickpea production constrained by several diseases. In which most of its soil borne diseases i.e. Fusarium wilt, dry rot and collar root rot and its foliar diseases are i.e. Ascochyta blight, Botrytis gray mold and Rust. Therefore, in this article, the symptom descriptions and management of disease in an integrated manner would help us to identify, diagnose the disease and to manage disease before its occurrence become a major yield limiting factor in all chickpea growing regions of India.

Aschocyta Blight of Gram

Pathogen: Aschocyta rabiei (Phoma rabiei)

Symptoms

Circular, water-soaked spots on leaves and pods.

Elongated spots on petioles and stems.

These spots coalesce and cover entire leaf which turns brown, represent a scorched appearance on leaves and buds.

On pods the pycnidia (black dot like bodies) arranged in concentric circles.

After complete girdling of a stem, the parts above the lesion droop and wilt.

On pods affected area tend to round, sunken, with pale centers and dark margins.

Integrated Management

Use of disease free seed, low seed rate, and wider row spacing.

Use of resistant varieties such as C 12/34, C 235, G543, GNG 146, Gaurav, BG 261, AUG 480, Pusa-256 and PBG-1.

Removal and destruction of dead plant debris.

Intercropping with cereals (wheat, barley) and mustard to reduce spread.

Deep summer ploughing is recommended.

Seed treatment with thiram and Benomyl @ 2g/kg or calixin and thiabendazole @3g/kg.

Foliar application with dithianon or chlorothalonil @ 3g/l.

Chickpea Wilt

Pathogen: Fusarium oxysporium f.sp. ciceri

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Symptoms

The affected seedlings show drooping of the leaves and pale color collapse and fall down on the ground.

Collapse of the stem.

Adult plants, initial symptoms drooping of petioles and rachis along with leaflets show fading of the green colour and plants look like dull green.

Gradually all leaves turn yellow and straw coloured.

Roots and stem of affected plants, when spit vertically show a brown internal discoloration of pith and xylem tissues.


Roughing of wilted plants.

Use of resistant varieties such as Pusa 212, Phul G-5 Avrodhi, AUG 480, ICP 12237-12269, ICC 1069, ICC 10466, ICC 858, and 9001.

Delayed sowing, plants spaced at 7.5 cm, planting of seeds at proper depth (10-12 cm).

Low seed rate and mixed cropping of chickpea with wheat and bar seem.

Soil solarization during summer month.

Avoid planting at poorly drained and highly acidic soil (pH <6.5).

Seed treatment with carbendazim @ 2.5g/kg and Benlate 1.5g/kg.

T. viride seed treatment @ 5g/kg of seed.

Rust of Gram

Pathogen: Uromyces ciceris

Symptoms

First symptoms appear initially as numerous small, oval or round, light brown to dark brown, powdery pustules, appear on both surfaces of leaves.

These pustules are coalesce and sometimes form a ring.

They are also found on stems, floral parts and pods.

Telia are seen at the end of the season.

Severely infected plants dry up prematurely.


Plant only resistant varieties like Gaurav.

Early sowing.

With the appearance of first symptoms, application of 0.2% Mancozeb 75 WP and two more sprays at 10 days interval.

Collar Rot

Pathogen: Sclerotium rolfsii

Symptoms

Drying of plants whose foliage turns slightly yellow before death.

Collar rot is seen at the seedling stage, particularly if the soil is wet.

Affected seedlings turn yellow. Young seedlings may collapse, but older seedlings

dry without collapsing.

When uprooted, the seedlings show rotting at the collar region and downwards. The rotten portion is covered with white mycelial growth.

A white mycelial covering seen on the tap root of completely dried seedlings.

If affected seedlings are uprooted from the moist soil in the early stage of infection, sclerotia (1 mm in diameter), attached to mycelial strands around the collar.


Deep summer ploughing and avoid excessive vegetative growth.

Avoid excessive irrigation and adopt wider spacing.

Avoid planting in the poorly drained and highly acidic soil (pH <6.5)

Seed treatments with Vitavax 200® @ 3g/kg seed.

Dry Root Rot

Pathogen: Rhizoctonia bataticola

Symptoms

Drooping of petioles and leaflets is confined to those at the top of the plant.

Sometimes the topmost leaves are chlorotic.

The leaves and stems of infected plants are usually straw colored, but in some cases the lower leaves and stems are brown.

The lower portion of the taproot usually remains in the soil when plants are uprooted.

Tap root is dark, shows sign of rotting and it is devoid most of its lateral roots.

Dark, sclerotial bodies can be seen on the roots exposed.


Sowing should be done on the time so that crop escapes hot weather.

Avoid planting in the poorly drained and highly acidic soil (pH <6.5).

Seed treatment with thiram and captan @ 3g/kg seeds.

Phytophthora Root Rot

Pathogen: Phytophthora medicaginis

Symptoms

Symptoms of phytophthora root rot in chickpea can develop from seedling emergence to near the maturity.

The disease is commonly causing wilting, chlorosis and rapid death of plants.

Patches of dead plants are seen in the field. Symptoms on individual plants are yellowing and drying of foliage with basal rot symptom on stem and decay of lateral roots and the lower portion of the taproot.

On the upper portion of the taproot, dark brown to black lesions are seen, which in some cases extend to the stem base.

The advancing margins of these lesions are

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reddish brown.


Crop rotation with wheat.

Avoid planting in the poorly drained soil.

Avoid planting in highly acidic soil (pH <6.5).

References Nene, Y.L., and Reddy, M.V. 1987. Chickpea diseases

and their control. Pages 233-270 in The chickpea (Saxena, M.C., and Singh, K.B., eds.). Wallingford, Oxon, UK: C.A.B. International.

Nene, Y.L. 1979. Diseases of chickpea. Pages 171-187 in: Proc. Int. Workshop on Chickpea Improvement. ICRISAT. Hyderabad, India, 298 pp.

Nene YL, Reddy MV, Haware MP, Ghanekar AM, Amin KS, Pande S and Sharma M. 2012. Field Diagnosis of Chickpea Diseases and their

Control. Information Bulletin No. 28 (revised). Patancheru, A.P. 502 324, India: International Crops Research Institute for the Semi-Arid Tropics. 60 pp. ISBN 92-9066-199-2. Order code: IBE: 028.Nene.

AICRP, 2016. http://www.aicrpchickpea.res.in/plant_path.htm.(retrived on 24/10/16).

Kaiser, W. J. Diseases of Chickpea, Lentil, Pigeon Pea, and Tepary Bean in Continental United States and Puerto Rico 1981. Economic Botany, Vol. 35, No. 3, pp. 300-32.

Chandrashekar, K; Gupta, OM; Yelshetty, S; Sharma, O.P; Bhagat, S; Chattopadhyay, C; Sehgal, M; Kumari, A; Amaresan, N; Sushil, S.N; Sinha, A.K; Asre, R; Kapoor, K.S; Satyagopal, K. and Jeyakumar, P. 2014. Integrated Pest Management for Chickpea. pp. 43


Allelopathy: A Promising Biological Control M. L. Meghwal

Department of Plant Pathology Rajasthan college of Agriculture, Maharana Pratap University of Agriculture & Technology, Udaipur. 313001.


The term allelopathy (allelon, to each other; pathos, to suffer) was coined by German scientist Hans Molisch in 1937. Observations on allelopathy, however, were recorded 2000 years ago (Putnam and Tang, 1986; Rice, 1995) and modern scientists described the phenomenon in the 1920s. Massy (1925) reported that black walnut (Juglans nigra) and butternut walnut (J. cinerea) caused wilting and dying of alfalfa, tomato and potato and associated the toxicity of black walnut with synthetic juglone (5-hydroxy-ἀ- napthaquinone) and reported its toxic effect on alfalfa and tomato. Elroy L. Rice in 1974 defined allelopathy as the effect(s) of one plant (including microorganisms) on another plant(s) through the release of chemical compound(s) in the environment. The effect could be either inhibitory or stimulatory, depending upon concentration of the compounds. The compounds involved in allelopathic interference are often termed allelopathic compounds, allelochemicals, or phytotoxins. Because of the rapid degradation properties of allelochemicals, most of these naturally occurring compounds have no lasting harmful residual effects to the environment

Some reports suggest that allelochemicals from plant tissues or microorganisms may be toxic to weeds, microorganisms and crops and thereby impact on plant and/or microbial biodiversity. Patrick reported that certain allelochemicals from decomposing plant tissues have potential for control of soilborne plant pathogens such as Pythhium spp., Fusarium spp., and Thielaviopsis basicola (Berk. & Br.) Ferr. Moyer and Huang (1997) found that aqueous extracts of lentil oat,

canola and barley straws at 1% concentration were toxic to seed germination of some weed species such as stinkweed, flixweed, and downy brome but were non-toxic to seed germination of wheat. The aqueous extracts from these crops at 2% concentration also effectively controlled the production of apothecia from sclerotia of Sclerotinia sclerotiorum (Lib.) de Bary, an important soilborne pathogen with wide range of hosts, except for the aqueous extract of wheat straw, which was ineffective in control of the pathogen.

The allelopathic effects of compounds could be due to (i) direct release of chemical compounds from donor plant (ii) degraded or transformed products of released compounds resulting from abiotic and biotic soil or water influences (iii) effects of released compounds on physical, chemical and biological soil and water characteristics or (iv) induction of released biologically active compounds by a third species. Many weeds are considered troublesome in cropping systems and approximately 250 weed species are known to be problematic in agriculture. Allelopathy has been suggested as a likely mechanism of interference in many weed species. There are some interesting studies which convincingly prove allelopathy. Soil infested with Polygonella myriphylla significantly suppressed seed germination and growth of Bahia grass (Paspalum notatum)

The allelopathic effects of many crop species have been observed on other crop and weed species. It is well known that crop cultivated in rotation produce higher yields than those grown

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in monoculture. Saponins from alfalfa rhizosphere inhibit growth of barley, wheat, radish and alfalfa. However redclover (T. pratense) growth was not affected. Allelopathy and autotoxicity are dependent on the type and duration of interaction between crops. They termed chemical interactions between crops within a season as “short term” allelopathy (or short term autotoxocity) and chemical interference beyond one season as “long term” allelopathy (or long term autotoxicity). Crop and weed residue have been demonstrated to interfere allelopathically with succeeding crop species. Decomposing rye residue inhibited respiration in tobacco seedlings. The residues were also responsible for delayed seed germination and reduced root growth of tobacco and lettuce. Hicks (1989) reported allelopathic effect of wheat straw on germination, emergence and yield of cotton. They found that the maximum inhibition in cotton germination and emergence occurred when wheat straw was mixed throughout the soil. Residues of several cover crops such as winter wheat, barley, oat, rye, sorghum and Sudan grass, have allelopathic potential to suppress weeds. Cereals crops such as wheat, maize and rye released hydroxamic acids in soil through root exudation, this helps in detoxification of triazine herbicides. Velvet bean (Mucuna pruriens var. utilis), a legume cultivated for green manure, produce L- DOPA (L-3,4-dihydroxyphenylalanine) which helps to improve yield of graminaceous crops and has the ability to smother noxious weeds such as purple nutsedge and cogon grass. Rice crop produce phenolic compounds like 4- hydroxybenzoic, 4- hydroxyhydrocinnamic and 3,4- dihydroxyhydrocinnamic acids which has allelopathic potential against growth of barnyard grass, Trianthemma portulacastrium, Heteranthea limosa, and Ammannia coccinea. This will help for formulating breeding strategies to exploit allelopathic rice cultivars in biocontrol programs.

Bacterial Allelochemicals

The increasing concern regarding synthetic

chemicals in agriculture has promoted the interest in allelochemicals of plant growth-mediating microorganisms. Thus, bacteria and their allelochemicals have been evaluated as biocontrol agents. The fact that natural products are often rapidly biodegraded in nature and do not accumulate in soil or contaminate the water table has promoted relevant research. As a result, a large number of allelochemicals, related to a wide variety of chemical groups, have been isolated and characterized from nonpathogenic soil-borne bacteria during the last decade.

In contrast to the specific effect of allelochemicals that often characterize pathogenic microorganisms, allelochemicals released by saprophytic bacteria are often nonspecific, affecting many species of plants. For example, herbicidin from Streptomyces saganonensis applied at 30 to 300 ppm inhibited several annuals and perennials of monocotyledonous and dicotyledonous plants. Nevertheless, certain allelochemicals exhibit some specificity. For example, blasticidin and 5-hydroxylmethyl-blasticidin S from the nonpathogenic Streptomyces sp., applied as foliar spray at 100 mg/m2 were more phytotoxic to dicots than to monocots. When these compounds were applied to soil, dicot plants were inhibited by 98 and 64%, whereas monocots were almost unaffected.

References Hicks, S.K., Wendt, J.R. Gannaway, J.R. and Baker,

R.B. 1989. Allelopathic effect of wheat straw on cotton germination, emergence and yield. Crop Sci.29, 1057-1061.

Moyer, J. R., and Huang, H. C. 1997. Effect of aqueous extracts of crop residues on germination and seedling growth of ten weed species. Bot. Bull. Acad. Sin. 38:131- 139.

Putnam, A.R. and Tang, C.S. 1986. Allelopathy: State of science. In “The science of allelopathy” pp1-19.Wiley, New York.

Rice, E.L. 1995. “Biological control of weeds and plant diseases: Advances in applied in Allelopathy” University of Oklahama Press, Norman.


Cotton Leaf Curl Disease: A Potential Threat to Cotton Production

Anupam Maharshi1, Priyanka Swami2 and Prachi Singh1

Ph.D. Scholars, 1Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, BHU, Varanasi – 221005, 2Department of Agrometeorology, GBPUA&T, Pantnagar- 263145


Cotton has its own importance occupies the most prominent position in the agriculture scenario of the country, as well as Haryana owing to its importance as a cash crop. Cotton is relevant for textile industry as fiber crop and is also an

important oil seed crop in the world. China, India, The United States and Pakistan account for more than 70 per cent of global cotton production, while other important cotton producing countries are Australia, Brazil, Africa Franc Zone and Central

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Asia. China, India and Pakistan are expected to lead global cotton mill use and account for a combined 65 percent of world consumption. The major use of cotton lint is for the production of a variety of fabrics and related products. In India, cotton has an area of about 118.81 lakh ha with total production and productivity of 352 lakh bales and 503 kg/ ha respectively. In Rajasthan, cotton cultivated area is 4.47 lakh ha with total and productivity of 14.90 lakh bales and 609 kg/ ha, respectively (Anonymous, 2016). Among four cotton cultivated species, only two viz., G. hirsutum L. and G. arborium L. are grown in Rajasthan. G. hirsutum L. is susceptible whereas, G. arboreum is resistant to Cotton leaf curl disease (CLCuD). Maximum area under cotton cultivation in Rajasthan is covered under hirsutum varieties/hybrids which are susceptible to Cotton leaf curl disease (CLCuD).

Symptomatology of CLCuD

Cotton leaf curl symptoms were first reported in Nigeria in G. Barbadense cotton. Symptoms of cotton leaf curl virus disease may vary from variety to variety but a specific virus produces the same symptoms in different hosts. Most varieties in infected by CLCuGV exhibit dwarfing, overall stunting, reduced boll number and boll weight. Two types of vein thickening are produced by CLCuD i.e., main and small vein thickening. Main vein thickening was described by the dark green thickening of the distal end of the large veins of younger leaves while thickening of small veins was characterized by dark green or pale green thickening of fine veins of young leaves. These irregular thickenings of veins gradually extended and resulting in more or less continuous reticulation of veins. Begomoviruses generally produce three types of prominent symptoms: leaf curl, yellow vein and yellow or golden mosaic. Enation formation, thickening of veins and upward or downward curling of leaves are typical symptoms of CLCuD. The severely affected plants have bushy appearance with dark green colour, short internodes without flowers and bolls.

Alternate Hosts of Cotton Leaf Curl Virus

Alternate hosts play an important role in causing this virus to spread over cotton crop. They provide inoculum to the vector for transmitting the same in cotton. There are many ornamental plants and common weeds which have been found infected with whitefly- transmitted geminiviruses, Singh et al. (1994) reported appearance of the CLCuD on the Sidasps, Abutilon indicum, Hibiscus rosa-sinensis, and Althea roses on the basis of visual symptoms. In Phaseolus vulgaris, pepper, tomato and tobacco, transmission studies and ELISA showed the presence of CLCuV (Nateshan et al., 1996). Cotton leaf curl disease spread from the primary inoculum that is present in the off season in the form of weeds and other hosts. Convolvulus arvensis, Capsicum sps., Pathenium sps., Solanum

nigrum, Digeria arvensis, Lantana camara, Achyranthus aspera, Chenopodium album, Spinacea sps., Xanthium strumarium were also reported as host of CLCuD coat protein gene amplification (Monga et al., 2011).

PCR for Detection and Diagnosis of Viruses

In general, PCR is very useful in detection and diagnosis of viruses, viroids and other plant pathogens. Geminiviruses are well studied to detect and identification by PCR because they replicate via double stranded, circular DNA intermediate the explicative form which can serve as a template for amplification by PCR. The genome constitute of number of regions which are highly conserved between viruses and hence can be used to design degenerate PCR primers. Degenerate oligonucleotide primers, designated for amplification of an approximately 500 bp fragment of DNA-A of five well characterized whitefly transmitted geminiviruses were used in the polymerase chain reaction (PCR) to detect known or putative geminiviruses infecting seven plant species and originally obtained from Africa, India, America and Europe. A set of primers designed based on the conserved sequence of coat protein region were used for the detection of DNA-A in cotton leaf curl virus (CLCuV) infected weeds and cotton plants using PCR technique. The cotton leaf curl virus specific primer precisely detected the virus in infected cotton as well as in symptom less plants by amplification of 771 bp coat protein gene.

Losses due to CLCuD

Disease is reported to cause huge loss in various regions for instance, considerable seed cotton yield reduction in Rajasthan (32.9to 50.3%), Punjab (10.5 to 92.2%) and Haryana (39.4 to 81.4%) states of north India. Leaf curl disease is major diseases of cotton in India and causes yield loss to the tune of 79 per cent depending upon the stage of infection and cultivar. Loss estimation studies due to CLCuD were undertaken by Monga et al., (2012) at Faridkot, Ludhiana, Abohar and Hisar districts of Punjab and Haryana. Losses due to CLCuD on Bt cotton hybrids in north zone during 2009-12 ranged between 25.2-46.6 %. Cotton leaf curl disease is the most devastating natural calamity that reduces the quality and production of the cotton.

Management Strategies

Desi cotton shows resistance reaction towards the CLCuD.

Early sowing is appropriate to reduce CLCuD incidence.

Proper Cultivar selection is the best way to avoid CLCuD incidence.

Transgenic development using Viral coat protein gene may also an effective tool to overcome CLCuD infestation.

Removal of alternate host as they are the

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potential source of continuous availability of CLCuV in the cotton growing belt also a better way to reduce the cotton leaf curl viral disease.

Whitefly population can be minimized at later stages by judicious use triazophos 40EC @ 2.5ml/lt of water @ 1500ml /ha and Ethion @2000ml/ha (Anonymous 2009). Seed treatment of Imidacloprid 600 FS 9ml/kg seed is also effective.

Innovative interventions for the management of CLCuD trial at Sirsa, Hisar, Sriganganagar, Faridkot and Bhatinda showed minimum CLCuD PDI in Polo spray @0.1% followed by cow urine @5%, neem oil and cow urine + calcium nitrate combination (Anonymous, 2016).

References Singh, J., Sohi, A.S., Mann, H.S. and Kapur S.P.

(1994). Studies on whitefly B. tabaci (Genn.) transmitted cotton leaf curl virus disease in

Punjab. J. Insect Sci., 7: 194-198. Monga D., Chakrabarty P.K., Kranthi, K.R. (2011)

Cotton leaf curl virus disease in India- Recent status and management strategies. In: Fifth meeting of Asian cotton research and development network, Lahore, 23–25 Feb 2011.

Nateshan, H.M., Muniyappa, V., Swanson, M.M. and Harrison, B.D. (1996). Host range, vector relations and serological relationships of cotton leaf curl virus from southern India. Ann. appl. Biol., 128: 233-244.

Monga, D., Shekhon, P.S., Beniwal G., Singh, D., Patil, P.V., Dhoke, P.K., Ingole, O.V., Perane, R.R., Chattanavar, S.N., Sree Lakshmi, B. and Rao, M.S.L. (2012). Avoidable losses due to cotton diseases in India. Paper presented in International symposium on “Global Cotton Production Technologies vis-a-vis Climate Change” held at CCS, HAU Hisar from 10-12 October, 2012, pp 96-101.

Annonymous (2016) - AICCIP Annual Report (2014-15), All India Coordinated Cotton Improvement Project.

74. PLANT PROTECTION 14808

Spore Trapping: Principles and Methodology Dr. H. N. Kamble and A. G. Tekale

Assistant Professor, Department of Plant Pathology, College of Agriculture, Tondapur, Hingoli (M.S.)

Dispersal, dissemination or spread of pathogenic propagules from the production site plays important role in epidemiology, for causing primary or secondary infection. For successful disease progress, the propagules must move. This may on their own or it may be mediated through various agencies, viz., air, water, insects or nematodes, etc., without dispersal there will not be epidemic. Dispersal of plant pathogens, an area of immense importance, had not been well attended or ignored by the scientists. Following are some of the limitation in study of dispersal phenomenon:

1. Dispersal involves dimensions of time and space

2. Experiments under controlled conditions not possible

3. Results of field experiments are not comparable

4. Removal and deposition of propagules require knowledge of physics

5. Involvement of mathematical and computer models

The process of spore dispersal involved three phases:

1. Liberation or Removal of Spores from Parental Tissue

This may be an active process, involving biological or other form of energy or a passive phenomenon. There is lot of variation in amount of force required for removal of spores (Helminthosporium

maidis 0.018 dynes generated by a wind of 5 m/sec; while the spores of Erysiphe graminis takes fraction of this force for detachment.

The maximum wind speed required to remove a fungal spore from parental tissue is known as critical wind speed. If we see the structure of boundary layer of air just above the leaf surface, where fungal spores are produced. We find that normal wind speed goes on reducing as we go nearer to leaf surface. It has been found that if normal wind speed is 25 m/ sec, the wind speed at the leaf surface will be reduced to 5 m/ sec. This high speed (5 m/sec) is achieved for a fraction of time (10-3 Fe 10-4 sec) due to gusts: which are transitional or intermittent high speed winds for a very short time. The roughness of leaf surface and the ‘speed breakers’ in crop canopy are some of the actors which are responsible for creations of gusts.

2. Transportation or Flight of Spores

Once the spores are remove from parental tissue and cross the boundary layer, they come in air and move with wind like any other suspended particle. The convection currents take the action to different heights in atmosphere and the wind speed along with wind direction determine their destination. More the height spores gain, more is the distance they travel.

3. Deposition or Setting of Spores

Spores suspended in atmosphere and moving with air gradually settle down. Two processes are

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75. PLANT PROTECTION 14836

Host Resistance to Manage Mycotoxin Contamination Prachi Singh1* and Anupam Maharshi1

Ph.D. Scholars, 1Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, BHU, Varanasi - 221005


Mycotoxin is a toxic secondary metabolite produced by filamentous fungi of small molecular weight. They are usually toxigenically and chemically heterogenous but are grouped together only because the members can cause disease and death in human being and other vertebrates. All mycotoxins are of fungal origin but not all toxin compound produced by fungi are called mycotoxins. Mycotoxin is heat stable, not destroyed by canning or other processes. Mycotoxin is toxic in low concentration, other low molecular weight fungal metabolites as ethanol are toxic in high concentration are not considered mycotoxins. One or more mycotoxin can be produced by fungus at a time with no biochemical significance in fungal growth and development. Mycotoxin contamination is recognised as unavoidable risk because formation of fungal toxin is weather dependent and effective prevention is challenge to agriculture. Despite of all efforts to prevent mycotoxin contamination about 25% of world crop is affected by mycotoxin each year, with annual losses of around 1 billion metric tons of foods and food products (FAO Survey 2002/2003).

In 1934, in Midwest more than 5,000 horses died of moldy corn disease. Outbreak of turkey X disease killed more than 100,000 young turkeys, 20,000 ducklings & poults. The term mycotoxin was coined in 1962 in the aftermath of an unusual veterinary crisis near London and active research was conducted after 1960s. In 1972, there was Gibberella ear rot caused feed refusal in swine in the Corn Belt. In 1974, an outbreak of aflatoxicosis was reported from West India causing death of more than 100 human & more than 400 dogs due to moldy corn. This was first report of mycotoxin contamination from India.

Mycotoxin is a secondary metabolite produced by fungus and are resistant to canning and other processes and remain in plant and plant product even after death of fungus. Major mycotoxins as aflatoxins, fumonisins and ochratoxins found to be associated with maize disease are most prevalent in countries such as India, Pakistan and Bangladesh (Biomin mycotoxin survey program 2011). According to Ministry of Human and Family Welfare the permissible limit of mycotoxin in all food products is 30 ug/Kg.

Major Mycotoxins

Mycotoxins Producing fungi Commodities effected

Aflatoxins Aspergillus flavus, Aspergillus parasiticus

Corn, Cotton seed, peanut, soybean.

Ochratoxins Aspergillus ochraceus, Penicillum verrucosum.

Wheat, Barley, Corn, Oat

Trichothecenes Fusarium graminearum, F. poae, F. culmorum.

Corn, wheat, Barley.

Zearalenone Fusarium graminearum Corn, Wheat, Barley.

Fumonisins Fusarium proliferatum, Fusarium verticillioides.

Corn

Moniliformin Fusarium spp. (F. moniliforme)

Corn

Ergot alkaloids Claviceps purpurea, Claviceps fusiformis

Rye, other cereals

Source - (Bhatnagar et al., 2004)

Formation of mycotoxin is affected by a very diverse array of factors, broadly divisible into biological, physical and chemical factors (D’ Mello et al., 1997). Mycotoxin targets protein synthesis pathway especially DNA template, RNA template (mRNA, tRNA, rRNA), proteins, transcription, translation and cellular metabolic reactions (Bbosa et al., 2013).

Of all the methods available to date, conventional breeding and genetic engineering to develop host plant-based resistance to mycotoxin producing fungi appear to be valuable (Rajasekaran et al., 2006). Pedigree and backcross breeding methods have been extensively used to develop lines with new combination of agronomic traits and resistance to disease in maize (Menkir et al., 2006). Since the host resistance to mycotoxin producing fungi offer the most promising control of mycotoxin negating its adverse effect on human, animals and plant system. On the other hand there is need to create stringent regulations with defined tolerance limit for each product. Most widely used process followed for marker assisted breeding for resistance to mycotoxin contamination is as follows –

1. Identification of natural resistance and resistance mechanisms.

2. Identification of Resistance associated Proteins (RAPs)

3. Characterization of (RAPs) towards use as markers

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Resistance in maize to aflatoxin contamination is polygenic and complex therefore markers need to be identified to facilitate transfer of resistance traits. KSA (Kernel Screening Assay) used most widely to measure seed based resistance which represents core objective of corn host resistance. Resistance Associated Proteins (RAPs) in maize as aldolase reductase (ALD), glyoxalase I (GLX I), pathogenesis related protein 10 (PR-10), peroxiredoxin antioxidant (PER 1), trypsin inhibitor, ZmTI, has been characterised for use as marker for breeding against aflatoxin resistance (Cary et al., 2011). Induced resistance for inhibition of mycotoxin contamination is another approach. Resistance approaches has helped us to handle more than one mycotoxin at a time.

If resistance approach fails we can go for mycotoxin decontamination by chemical, biological and physical methods. HACCP (Hazard Analysis Critical Control Point) method is a well strategic plan to combat mycotoxins (Binder, 2007). Integration of host resistance with agronomic practices and post-harvest control can only provide protection in broad spectrum.

Conclusion: In tropical conditions such as high temperature and moisture, monsoon, seasonal rains and flash floods leads to fungal proliferation and mycotoxin production. Poor harvesting practices, improper storage and less than optimal conditions during transport and marketing can also contribute to fungal growth

and mycotoxin production. The prospects for preventing or reducing the adverse effects of mycotoxin in the future is promising task especially for developing countries like India where huge number of death occurs due to mycotoxin. Since chemical and other post-harvest method of detection and decontamination is costly. Host resistance is an economical method to provide long term protection to crops.

References Bbosa, S.G., Kitya, D., Odda, J., Ogwal-Okeng, J.

2013. Aflatoxins metabolism, effects on epigenetic mechanisms and their role in carcinogenesis. Health. 5 (10 A).

Binder, M.E. 2007. Managing the risk of mycotoxins in modern feed production. Animal Feed Science and Technology. 133: 149 – 166.

Cary, W.J., Rajasekaran, K., Brown, L. R., Luo, Meng., Chen, Z., Bhatnagar, D. 2011. Developing Resistance to Aflatoxin in Maize and Cotton seed. Toxins. 3: 678 – 696.

D’Mello, J.P.F., Macdonald. A.M.C. 1997. Mycotoxins. Animal Feed Science and Technology. 69: 155 – 166.

Menkir, A., Brown, L. R., Bandyopadhyay, R., Chen, Z., Cleveland, E. T. 2006. A USA-Africa collaborative strategy for identifying, characterizing, and developing maize germplasm with resistance to aflatoxin contamination. Mycopathologia. 162: 255 – 232.

Rajasekaran, K., Cary, J.W., Cleveland, T.E. 2006. Prevention of preharvest aflatoxin contamination through genetic engineering of crops. Mycotoxin Research. 22 (2): 118 -124.

76. ENTOMOLOGY 13496

Distribution of Insects Hadiya G. D., Patel A. D. and Khambhu, C. V.

Department of Entomology N. M. College of Agriculture, Navsari Agriculture University, Navsari-396 450, Gujarat

INTRODUCTION: It is not possible or even desirable to count all the insects in a habit. Therefore, to estimate the population density of a pest or the damage caused by it to the crop, one has to resort to sampling. Randomization and choice of sampling unit are the fundamentals of sampling. The total number of samples to be taken depends on a degree of precision required. In general, sampling programme is of two types, extensive and intensive. Extensive programme is conducted over broad areas to determine the species distribution or the status of injurious insect stages. In this, usually only a single insect stage is sampled and only one or a few samples are taken per season. On the other hand, intensive programmes are conducted as part of research in population ecology and dynamics. In this case sampling is done or most stages in life cycle of an insect are sampled and a high degree of precision sought.

Method of Sampling

I. It Situ Counts

Direct Collection: it involves direct counts or direct collection by hand in the field and often requires no special equipment but rely on good eye.

II. Knock Down

Jarring: A piece of cloth is placed on the ground and a branch is given jerk several times with the help of iron hook attached to the stick to dislodge to beetles. Beetle falling on the clothes are counted and also know drop sheet method. E.g: white grub

Heating: A special device the burlese funnel that heat the samples and other side cold place the insect are moved and that insect are collect. Eg: Store grain pest

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III Neting

Netting of insects is one of the most widely used techniques which are relatively simple and inexpensive.

Sweep netting: Muslin net is swept through the crop canopy and plant is jarred so that the insects present on the plant may fall into the net.

Vacuum netting: Engine power is used to create strong vacuum which suck the insect from plant canopy. E.g: Grass hoppers.

Arial netting: A truearial net is a mesh –bag net with a handle which is swept through the air to capture the insect.

IV. Trapping

Insects are attracted to different visual, chemical or olfactory cues to communicate with each other or find suitable hosts.

Lighat Trap: Many moths are attracted to short wavelength of the light or the blacklight. E.g: mothes, hoppers, and also beetles.

Bait trap: Bait trap rely on an insect olfaction or sense of smell for attraction. E.g: sorghum shoot fly

Pheromone trap: Pheromones are attract insect like Helicoverpa armigera

Malaise Trap: it is basically tent made of cotton or nylon mesh one side open that intercepts flying insect. The roof of the tent slopes upward to a peck where a container with some preservative is located. Insect move upward and into the container E.g: Whitefly.

Suction Trap: consist of wire gauze funnel leading to a collecting jar and motor driven fan is situated below the funnel to create the suction E.g: aphid and leaf hopper

Window Trap: this kind of interaction trap consist of a large sheet of glass that site in collecting trough supported by wooden legs. Insect flying in to the glass are knockdown in to the troughed container soppy water. E.g: flying insect

Water trap: It consist of shallow open pan or tray mooted on a wooden post which is filled with water having some detergent or an oil film to aid in wetting or downing the insect. E.g: in sampling rice pest

Sticky Trap: the insect get stuck in the adhesive applied to the trap’s surface and installing on the bamboo strip in various high. E.g: Aphid, flies.

Pitfall Trap: It consist of the smooth side container or a jar or bottle sunk in the ground with a funnel at the soil surface that empties into the container. E.g: carabidids, styaphylinid.

V. Removal Trapping

It involves reduction in pest population by removing individual through repeated catches so that catch per unit time decreases. The population

size is estimated from the rate at which the catch decreases.

Sieving: Dry and wet sieving methods are used to sample insect. One or more sieves of varying coarseness beginning with cores mesh to screen out large soil particles. And other debris and ending with fine mesh are employed.

Wet sieving: Follow the same principle as dry sieving except that water is used to facilities to movement of soil particle to the sieves.

Flotation: Flotation technique is another widely used extraction produce that may be used alone or in conjunction with sieving and other technique.

Method of Estimation of Density of Insect and Distribution

Estimation of Relative Density

1. Estimation are useful for making compression in space or time.

2. Measure actual number in the insect population.

3. such estimated are expressed in number per ground surface area number per acre

4. The following method is generally used. a) Catch per unit time: The sample collect by

sweeping with hand net. This is useful for grass hopper and plant bug.

b) Use of trap: The various type of trap including interception trap, flight trap,

Estimation of Absolute Density

1. Based on the kind of sampling technique. 2. It is compare population size in time and

space. 3. Many technique used relative estimate 4. Many techniques used relative estimate 5. Estimation the whole population 6. The line transcend method

a) Use of Quadrates. b) Capture, Marking, Release method.

III Estimation the Whole Population

1. The counting the whole population but it can be used are relatively infrequent even with vertebrate.

The Line Transect Method

1. If the we move in a line while watching a particular strip in front of us we can count the no of insect in counter.

2. The data base on this encounter can be estimating the absolute population.

3. This case of encounter between moving object is infection by a) Size of the object b) Their speed c) Their density

Use of Quadrates

It is difficult to count the whole no. in most case and one hend to resort to sampling in

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which a small proposal of the population is observed, generally that kind of sampling technique are employed.

In case of immobile from like insect larvae quadrate method can be effectively used the quadrate represent a known proportion of the total population and all individual all individual in the quadrate are counted.

Capture, Marking, Release method

It is difficult to assess the no of flying insect or

rodents which are highly mobile by any of the method here

The insect are first capture from the field marked with some suitable paint or dye, released in the field and capture the field and recapture to the along with the unmarked individual.

Death rate can also be calculated and it will facilitate competition between different forms in different condition.


Co-Evolution: Ant: Acacia Mutualsim Divya Bharathi, T.*, Abdul Khadar B. and Shaila O.

Ph.D. Research Scholar, Dept. of Entomology, Central Research Institute for Dryland Agriculture, Santhoshnagar, Hyderabad-500059

INTRODUCTION: Co-evolution is commonly believed to be important in the evolution of many plant characters and the ability of herbivores and pathogens to use plant as food and hosts. The term was invented by Paul Ehrlich and Peter Raven in 1964 in a famous article “Butterflies and Plants: a study in Co-evolution”. The concept of co-evolution was briefly described by Charles Darwin in “the Origin of Species”. Co-evolution may be defined as an evolutionary change in a trait o the individuals in one population in response to a trait of the individuals of a second population, followed by an evolutionary response by the second population to the change in the first. The term co-evolution usually refers to the joint evolution of two or more species or genomes, owing to interactions between them. Interactions include viz., inter-specific competition, mutualism, interactions between consumers and victims (Predator/prey, herbivore/plant, parasite/host relationships).

Obligate mutualistic relationships among species are ubiquitous and central to ecological function and the maintenance of biodiversity. Ant–plant relationship is a prominent example of mutualism. Mutualisms are interactions among different species that lead to net fitness benefits for all partners involved. In Ant-Acacia mutualisms, Acacia plants provide to ants an array of benefits viz., extra floral nectar, food bodies or nesting space. In return, ants may provide protection from herbivory (or) pathogens, pruning of neighbouring plants, and nutrient enrichment. Of these services, protection from herbivory is the best documented; plants without ants generally suffer higher levels of herbivory than conspecifics with ants present. Although these mutualisms can become very specific, the rewards traded among mutualist partners may also be attractive for non-mutualist organisms, i.e., exploiters that make use of the host-derived rewards without reciprocating. Whereas Acacia obligate plants (myrmecophytes) secrete EFN at high quantities and constructively,

to house and nourish symbiotic ants of Pseudomyrmex ferrugineus, facultative ones (non-myrmecophytes) secrete it only in response to damage, attracting generalist ants. These differences in plant-ant interactions make this genus Acacia highly suitable to study mechanisms that may determine species-specific interaction.

Ant and Acacia Mutualism

Many species of the plants in Acacia have mutualistic ants of the genus Pseudomyemex associated with them have long been termed as ‘Myrmecophytes’. In this species pair, the ant is dependent upon acacia for food and domicile, and the acacia is dependent upon the ant for protection from phytophagous insects and neighboring plants. The traits of the ant and acacia can be roughly divided into two groups (Table 1 and 2). Those features in which the mutualistic Acacia and Pseudomyrmex depart from their congeners.

TABLE 1: Acacia traits related to Ant-Acacia Co-evolution

General features of acacias Specialized features of swollen-thorn acacias (Coevolved traits)

Woody shrub or tree life form Woody but with very high growth rate

Plants of dry areas Plants of moisture areas

Reproduce from suckers Rapid and year round sucker production

Ecologically widely distributed Very widely distributed

Stipules often persistent Stipules longer persistent

Leaves shed during dry season Year round leaf production

Bitter tasting foliage Bland tasting foliage

Each species with a group of relatively host specific phytophagous insects

Each species with a few host specific phytophagous insects

Foliar nectaries Very enlarged foliar nectaries

Unmodified leaves Leaflets with tips modified into beltian bodies

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TABLE 2: Pseudomyrmex traits related to Ant-Acacia Co-evolution

General features of Pseudomyrmex

Specialized features of obligate acacias-ants (Coevolved traits)

Fast and agile runners, not aggressive

Very fast and agile runners, aggressive

Smooth sting, barbed sting sheath not inserted

Smooth sting, barbed sting sheath often inserted

Ignore living vegetation Maul living vegetation contacting the swollen thorn acacia

One queen per colony Sometimes more than One queen per colony

Colonies small Colonies large

Diurnal activity outside nest 24 hours activity outside nest

Few workers per unit plant surface

Many workers per unit plant surface

Discontinuous food sources and unpredictable new nest site

Continuous food sources and predictable new nest site

Founding queens forage far for food

Founding queens forage short distance for food

Not dependent on another species

Dependent on another species

Benefits to Acacia

Ants prevent herbivores from feeding on plant by killing them or chasing them off.

Ants remove any other plants growing nearby on their Acacia (which decreases competition)

Benefits to Pseudomyrmex Ants

A safe home (ants live in the trunk, and enter by chewing through the large hollow thorns).

Plant provides two food sources i.e., extra-floral nectarines which provide nectar; Beltian bodies which are high in protein.

Causes of ant Removal on Acacia

The number of herbivorous insects increased dramatically

The growth rate decreased dramatically

Did not grow well and none reproduced

Survival of plants over the course of a year declined dramatically

Thus, the removal of ants did not immediately kill Acacia, but the growth hampered in Acacia plant and none reproduced. So Acacia always needs ants Vis-à-vis ants also need Acacia, since they are never found elsewhere unless looking for new Acacia.


Bed Bugs: Cimex lectularius L. Patel Aditi, Khambhu Chirag, Hadiya Girish and Chauhan Rinki

Department of Entomology, N. M. College of Agriculture, Navsari Agriculture University, Navsari-396 450, Gujarat

Bed bugs are parasitic insects of the cimicidae family that feed exclusively on blood. Cimex lectularius, the common bed bug, is the best known as it prefers to feed on human blood. Other Cimex species specialize in other animals, e.g., bat bugs, such as Cimex pipistrelli, Cimex pilosellus, and Cimex adjunctus. The name "bed bug" derives from the preferred habitat of Cimex lectularius: warm houses and especially near or inside beds and bedding or other sleep areas. Bed bugs are mainly active at night, but are not exclusively nocturnal. During the day, they hide in cracks and crevices in walls, floors, beds, and furniture. When only a few bed bugs are present, they live close to human sleeping areas when numerous, they can be found in many rooms of the house. A characteristic “bed bug odor” is frequently present in a home infested with bed bugs. All members of the bed bug family feed on the blood of birds or mammals.

Identification: Bed bugs are oval, chestnut brown insects and are flattened from top to bottom. Adult bed bugs measure about ¼ inch in length. The mouthparts are shaped into an elongated proboscis, which, when not in use, is

held directed backward underneath the body. When a bug is ready to feed, the proboscis is extended forward and the stylets within are thrust into the skin of a host. Mated female bed bugs deposit their eggs in their resting places. One female will produce about 345 eggs during her lifespan.

Life History: The bugs grow by molting several times. Nymphs look very much like the adults, except they are smaller and not sexually mature. There are five nymphal molts, and each nymph must have a blood meal to be able to molt to the next stage. Adults feed once a week on average but feed many times during their four month or longer lifespan. It is common for bed bugs to come into a home via secondhand articles and furniture.

Injury: Despite the fact that the bed bug can acquire many human disease organisms during feeding, there have been no documented cases of disease transmission as a result of bites. However, their bites can produce irritating, itching, and burning sensations. Bed bugs feed rapidly, becoming engorged in less than ten minutes. The act of biting is usually not felt, but later there is an

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allergic reaction to the protein found in the bed bug’s saliva. A colorless wheal or lump develops at the bite location in contrast, flea bites have reddish centers. Discomfort from bed bug bites may last a week or more. Occasional bites indicate a beginning light infestation of adults many bites result from a heavy, longstanding population of nymphs and adults.

Management: Eradication of bed bugs frequently requires a combination of non-pesticide approaches and the occasional use of pesticides. Mechanical approaches, such as vacuuming up the insects and heat treating or wrapping mattresses, are effective. A combination of heat and drying treatments is most effective. An hour at a temperature of 45 °C (113 °F) or over, or two hours at less than −17 °C (1 °F) kills them a domestic clothes drier or steam kills bedbugs. For public health reasons, individuals are encouraged to call a professional pest control service to eradicate bed bugs in a home, rather than attempting to do it themselves, particularly if they

live in a multifamily building. Resistance to pesticides has increased significantly over time, and harm to health from their use is of concern. The carbamate insecticide propoxur is highly toxic to bed bugs, but it has potential toxicity to children exposed to it, and the US Environmental Protection Agency has been reluctant to approve it for indoor use. Boric acid, occasionally applied as a safe indoor insecticide is not effective against bed bugs because they do not groom. The fungus Beauveria bassiana has ability to control bed bugs. As bed bugs continue to adapt pesticide resistance, researchers have examined on the insect's genome to see how the adaptations develop and to look for potential vulnerabilities that can be exploited in the growth and development phases. Natural enemies of bed bugs include the masked hunter insect, cockroaches, ants, spiders, mites, and centipedes. However, biological pest control is not considered practical for eliminating bed bugs from human dwellings.


Odour Guided Host Findings in Anthropophilic Mosquitoes 1K. L. Manjunatha,1T. G. Avinash, 2Parasappa H Hulagabala

1Ph.D. Scholar, Dept. of Entomology, University of Agricultural Sciences, GKVK, Bangalore-65 2Field Assistant, Horticultural Research and Extension Station, Sirsi, Uttara Kannada-581401

Olfactory-driven behaviors enable mosquitoes to locate host animals from which they obtain blood meals essential to produce eggs. Mosquito host-seeking behavior can be dissected into sequential steps, each of which relies heavily on olfactory information from hosts. Volatile compounds from animals such as 1-octen-3-ol and CO2 trigger flight orientation behavior. These volatiles are mainly detected by olfactory receptor neurons (ORNs) present in the maxillary palp of mosquitoes. Less volatile host-emitted compounds, such as carboxylic acids, are critical to the mosquito’s ability to discriminate a suitable host from a non-preferred host animal at close range. The final step of blood-feeding behavior occurs when the stylet probes the host skin to obtain blood. This is a critical and dangerous moment for female mosquitoes, because unsuccessful probing might alert the host animal to their presence, which may result inconsiderable risks. Therefore, mosquitoes try to locate blood vessels underneath the host skin rapidly and efficiently without provoking defense measures in the host (Jung et al., 2015)

Jung et al., (2015) Provide new findings that the stylet, is an essential apparatus for the stage in blood feeding. Indeed, the stylet possesses a number of sensory hairs located at the tip of the stylet. These hairs house olfactory receptor neurons that express two conventional olfactory receptors of Aedes aegypti (AaOrs), AaOr8 and AaOr49, together with the odorant co-receptor

(AaOrco) and Inhibition of gene expression of these AaOrs delayed blood feeding behaviors of the mosquito.

The composition of the skin microbiota affects the degree of attractiveness of human beings to Anopheles gambiae mosquito species. Bacterial plate counts and 16S rRNA sequencing revealed that individuals that are highly attractive to A. gambiae have a significantly higher abundance, but lower abundance of bacteria on their skin than individuals that are poorly attractive (Verhulst et al., 2011). Thierry et al., (2010) reported that Water consumption had no effect on human attractiveness to A. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers’ odours).

Presence of Lactic acid and carbon dioxide, ammonia, and short-chain fatty acids contribute to the attractiveness of Aedes aegypti mosquitoes to human. The key compound is lactic acid, which is produced by eccrine sweat glands of human (Geier et al., 2002).

Renata et al., (2013) showed that Plasmodium falciparum infected A. gambiae mosquitoes were significantly more attracted to human odors than uninfected mosquitoes. Both P. falciparum infected and uninfected mosquitoes landed

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significantly more on a substrate emanating human skin odor compared to a clean substrate. However, significantly more infected mosquitoes landed and probed on a substrate emanating human skin odor than uninfected mosquitoes.

These odor guided host findings of anthropophilic mosquitoes expected to be open the door to make synthesize the artificial odor blends that mimic the particular human scent for anthropophilic mosquitoes. Such blends could increase the efficacy of the existing mosquito traps enormously and it would also be effective without the addition of carbon dioxide.

Special Reference Jung, J.W., Baeck, S.J., Haribalan, P., Hansson, B.S.

and Hyung, W.K., 2015, A novel olfactory

pathway is essential for fast and efficient blood feeding in mosquitoes. Scientific reports., P:1-10.

Geier, M., Oliver, B., Birgit, S., Andreas, R. and Jurgen, B., 2002, Odor guided host finding of mosquitoes: identification of new attractants on human skin. Proceedings of 4th international conference on urban pests., P:37-46.

Renate, C.S., Geert, G., Marga, V.B., Gezen, S., Willem, T., Roert, W.S. and James, G.L., 2013, Malaria infected mosquitoes express enhanced attraction to human odor. PLos ONE., 8:1-3.

Thierry, L., Louis, C.G., Kounbobr, R.D., Eric, E., Didier, F. and Frederic, T., 2010, Beer consumption increases human attractiveness to malaria mosquitoes. PLos ONE., 5:1-8.

Verhulst, N.O., Qiu, T., Hans, B., Chris, M., Dan, K., Knight, R. and Renate, C.S., 2011, composition of human skin microbiota affects attractiveness to malaria mosquitoes. PLos ONE., 6:1-7.


Non-Chemical Approaches for the Management of Stored Grain Insect Pests

1Ranvir Singh and 2Dharam Singh Meena

1Department of Agricultural Entomology, 2Department of Agronomy University of Agricultural Sciences, GKVK, Banglore-560065

INTRODUCTION: Chemical insecticides have been used extensively in grain storage facilities to control stored-product insect pests. Because of the development of resistance to synthetic insecticides, the concerns about worker safety and the demands by consumers for finished products free of insecticide residues, peoples are looking for alternatives to chemical insecticides. The aim of non-chemical control is to make the habitat unsuitable for the growth and reproduction of stored-product insects.

Drying

Most stored grain insect thrive at moisture contents of 12 to 15 per cent, so reducing moisture content of the grains is an alternative for control. There are several types of grain drying methods such as sun drying, solar dryers and using ambient air or heated air.

Low Temperature: Optimum temperatures for growth and development for most stored-stored product insects are between 25 and 350C. There are several ways to lower the temperature of the grain mass, either through turning grain over, ambient air aeration or chilled aeration. Turing grain from one site of storage to another will break up localized hot spots. Chilled aeration is the process of blowing refrigerated air through a grain mass, can reduce grain temperatures and subsequently the insect populations.

High Temperature: Insect’s development rapidly falls with increasing temperature, above that require for normal development. At temperature above 450C most stored product insects die within 24 h. Grain can be heated by

passing a thing layer of grain under an infrared or microwave radiation source. A recent method is the use of fluidized bed heating where air is used as the heat transfer medium because it transfers heat rapidly.

Controlled Atmospheres: A controlled atmosphere is one in which a target concentration of a particular gas is maintained. This can be achieved by addition of CO2 gas in the storage structure.

Modified Atmospheres: A modified atmosphere is one in which the relative abundance of atmospheric gases changes from tolerable to toxic. This can be achieved under hermetic storage of an infested stored product in which the activity of aerobic arthropods and microbes consume the O2 in a gas-tight structure and generate CO2, resulting in a decrease in O2 concentration and an increase in CO2 concentration, causing asphyxiation.

Ozonation: Ozone (O3) has a half-life of 20-50 minute, rapidly decomposing to diatomic oxygen, a natural component in the atmosphere. With a short half-life, it reverts back to naturally occurring oxygen leaving no residue on the product or to dispose of.

Irradiation: Disinfection of stored product can be conducted using ionizing radiation such as gamma rays, which have the potential to dislodge electrons from chemical bonds in molecules, and nonionizing radiation such as radio frequencies, microwaves, or infrared rays, which do not break bonds but essentially heat the product and the insects by vibrating bonds in water. Insect eggs

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and young larvae exposed to effective doses of gamma rays fail to develop to adults, and treated adults are reproductively sterile.

Inert Dusts: Inert dusts are chemically unreactive dusts that have insecticidal capability, killing by physical rather than chemical means. Inert dusts kill insects by causing moisture to move out of the insect’s body, either by scratching through (diatomaceous earths) or absorbs (silica aerogel) the insects waxy coating. The main advantage of using inert dusts is that they are nontoxic to humans and animals.

Insect Growth Regulators

Insect growth regulators are chemicals which mimic hormones that control molting and thereby disrupt development. They exhibit low levels of toxicity to mammals and inherent high level of food safety. Juvenile hormone analogs such as methoprene, hydroprene, and pyriproxyfen are most commonly used IGRs in storage system.

Microbial Insecticides: Microbial insecticides contain micoroorganisms or their by-products. Microbial insecticides are especially valuable because their toxicity to non target animals and human is extremely low. Many fungi like Beauveria bassiana and Metarhizium andisopilae and the bacterium Bacillus thringiensis have been tested agaisnst stored grain pest. Spinosad is an insecticide derived from metabolites in the fermentation of the actinomycete bacterium Saccharopolyspora spinosa Mertz and Yao. Spinosad is currently registered by the U.S. EPA with a residue tolerance concentration of 1.5 ppm for use on stored grain.

Biological Control: Many species of natural enemies occurs in stored product ecosystem and these species represent potential biological control agents for the desired pests. The anthocorid bug, Xylocoris flavipes (Reuter) is a cosmopolitan predator to different pests of stored commodities namely Tribolium castaneum, T. confusum, Rhizopertha dominica and Trogoderma granarium.

Botanicals: Plant materials such as neem, pyrethrum etc. are commonly used to protect the stored grains from insects pest. But various problems with botanicals are lack of consistency, safety concerns, and sometimes odour.

Entoleter: In entoleter centrifugal force is used to break infested kernels and kill stages of storage pests while whole grains are unaffected.

Behavioral Manipulation

Various traps are employed in the storage structures to capture the insect pests. Most commonly used are the pheromone baited traps, probe traps, pitfall trap and light trap.

References Aziz S. E. A. E. (2011). Control strategies of stored

product pests. Journal of Entomology. 8(2): 101-102.

Oladele O. I. and Adebo G. M. (2014). Awareness and use of non-chemical prevention and control of storage pests of grains: and international audience perspective. Mediterranean Journal of Social Sciences. 5(15): 150-155.

FAO:http://www.fao.org/docrep/x5048E/x5048E0t.htm


Reproductive Insect Ecology Rishikesh Mandloi*

Ph.D. (Ag.) Scholar*, Department of Entomology, College of Agriculture Jabalpur JNKVV, Jabalpur- 482004 (Madhya Pradesh) India


INTRODUCTION: “Reproductive insect ecology help to us for study of basic estimate of population both ecologist and entomologist for purpose of understanding to population dynamics of a species and basis for development management strategies”.

Reproduction

Population increase in size because of natality mean the production of new individual in broadest scenes include birth, hatching, germination and fission (kerbs 1978). Reproduction in insects is affected by a wide range of abiotic and biotic (intrinsic and extrinsic) factors. Which are usually studies to determine the extent of their influence of the population dynamics of a species?

Sexual Selection

Actually sexual selection is a part of natural selection, evolutionary change occurs through variation between individuals; some variants give the individual an extra survival probability is known as a natural selection. Natural Selection may take a variety of forms and act on any behavioral, morphological, developmental or physiological traits of an organism. However, certain types of selection are unique in their features, and they are often treated as special categories of selection. One of these "special" categories is that of sexual selection. Darwin was the first to realize the existence and importance of sexual selection, which he defined as "The advantage which certain individuals have over

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others of the same sex and species solely in respect of reproduction". The modern concept of sexual selection is usually restricted to characteristics which affect mating success, not reproduction in general, but most organisms must mate in order to reproduce!

Defined Two Basic Types of Sexual Selection Darwin (1871)

Sexual selection rises in response to either female choice or male competition.

INTRA = within

INTER = between

Intera-sexual Selection (INTRA = within) or Male Competition (Generally seen as Male-Male Competition)

“Interasexual selection favor treat that affect the ability of member of a same sex with compete with one other for mate” Intrasexual selection (intra meaning within), described as selections of traits that increase ability of the same sex too compete to obtain members of the opposite sex. Interasexual selection occurs for territory and access to females, or area on mating grounds in which displays take place.

Male-male competition for mates can lead to intense battles that involve the use of horns, hooves, and teeth. Often this affects fighting ability and, more successful fighters receive more copulations than less successful ones. If one male is physically able to prevent another male form mating with a perspective female, then these strong competitors have a selective advantage despite potential female preferences for other types of males.

Male-male competition is the driving force for why we see males of a species being much larger than females; Interasexual selection is selection within the same sex. For example, some male animals compete against one another, physically, for access to females. So something like big antlers, huge sharp teeth, or similar weaponry that can be used against other males of the species as a means of mating with females is a selective advantage. Males compete for access to females, the amount of time spent mating with females, and even whose sperm gets to fertilize her eggs. For example, male damselflies scrub rival sperm out of the female reproductive tract when mating. In the one it is between individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive’

Sexual dimorphism in insects is known as a phenotypic difference between males and females of the same species. The prototypical example is for differences in characteristics of reproductive organs.

Sexual dimorphism in insects such as staghorn beetle, song in orthopteriod and cicada and wing color in butterflies and odonates help to recognize the operation of sexual selection,

Intersexual Selection (INTER = between) (Generally seen as Female Choice)

Favor treat that attract member of the opposite sex. Intersexual selection is in which a female chooses a mate based on elaborate ornamentation or behavior. Intersexual selection influences the evolution of secondary sexual characteristics, which determines the relative ≥attractiveness≤ of members of one sex to another, such as courtship displays and male plumage

Intersexual selection is selection between the two sexes. For example, the bright plumage of a male peacock does not help it physically overcome rival males. But female peacocks tend to prefer male peacocks with bright plumage: a brightly colored male peacock has a selective advantage. It is selection based on one sex of the species preferring some characteristic in the other sex of the species.

Females choose which males to mate with, how long to mate, and even whose sperm will fertilize her eggs. Some females can eject sperm from an undesirable mate. Whilst in the other the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners’.

Insect Mating Behavior

I. Sexual selection theory II. Natural history of insect mating systems

A. Indirect sperm transfer -- apterygota i) Collembola mating dance (Collembola) ii) Springtail bondage (Zygentoma)

B. Direct sperm transfer -- pterygotes i) Resource defense-based mating systems

i) Female emergence sites -- Cicada killer wasps (Hymenoptera: Sphecius speciosus)

ii) Female oviposition sites -- Lucanid beetles (Coleoptera: Lucanidae)

ii) Communication-based mating systems i) Acoustic communication -- Hemiptera

and Orthoptera [In particular, Acrididae (crickets); Tettigoniidae (katydids); Gryllotalpidae (mole crickets)].

ii) b) Chemical communication -- Trichoptera + Lepidoptera use pheromones produced by females and detected by males.

iii) Visual communication -- Fireflies (Coleoptera: Lampyridae; Photuris and Photinus)

iii) Sperm competition i) Prolonged copulation -- Love bugs

(Diptera: Bibionidae) ii) Sperm plugs -- honey bees

(Hymenoptera: Apidae) iii) Sperm removal -- damselflies

(Odonota: Calopteryx maculata)

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iv) Traumatic (hypodermic) insemination -- Bed bugs (Hemiptera)

iv) Female choice and gift giving i) Mormon cricket “nuptial gifts”

(Orthoptera; Anabrus) ii) Scorpion flies (Mecoptera;

Hyalobittacus apicalis) iii) Dance flies “fiddling nuptial gift”

v) Sex role reversals i) Belostomatidae (Hemiptera) – male

parental care in toe-biters.

What is Mating System?

“A mating system is a way in which a group is structured in relation to sexual behavior. The precise meaning depends upon the context”.

The term of mating system is used to describe how male and female obtain mates in a population a particular mating system may be characterized by the event surrounding pair formation, courtship, copulation and post copulatiery event individual male and female engage in reproductive behavior

Types of Mating Systems

The following are some of the mating systems generally recognized in animals:

1. Monogamy- One male and one female have an exclusive mating relationship. The term "pair bonding" often implies this. This is associated with one-male, one-female group compositions. In monogamy, both males and females have only one mate at a time. Modern biological researchers using the theory of evolution approach human monogamy as the same in human and non-human animal species. They postulate the following four aspects of monogamy: a) Marital monogamy refers to marriages of

only two people. b) Social monogamy refers to two partners

living together, having sex with each other, and cooperating in acquiring basic resources such as shelter, food, and money.

c) Sexual monogamy refers to two partners remaining sexually exclusive with each

other and having no outside sex partners. d) Genetic monogamy refers to sexually

monogamous relationships with genetic evidence of paternity.

2. Polygamy - In a polygamous mating system, individuals of one or the other sex have more than one mate during the breeding season. When males in the population mate with more than one female, it is called polygyny (poly means "many," and gyne means "female"). Males compete for females, and this leads to strong selection for traits that either attract females (for example, elaborate songs or calls, bright coloration, and courtship displays) or allow males to compete effectively with other males (for example, aggressiveness, large size, and fighting aids such as antlers). Polygyny is common in species where males are less likely to provide parental care (and thus may increase their. a) Polygyny – (many females) a type of

polygamy where a male mates with several females.

b) Polyandry – (many males) a types of polygamy where a female mates with several males.

c) Polygynandry – several females and several males form a communal breeding unit.

d) Promiscuity – indiscriminate sexual encounters, usually brief, where both males and females mate with several individuals.

3. Promiscuity- A member of one sex within the social group mates with any member of the opposite sex. This is associated with multi-male, multi-female group compositions.

References Dent D.R. And Walton M.P. Method of ecological and

agricultural entomology, CAB international 198 Madison Avenue New York, USA.

P.J. Gullan and P.S. Cranston, The insect an outline of entomology Blackwell publication UK AWASTHI V.B., Principles of Insect Behaviour Scientific Publisher Jodhpur India

INTERNET


Effect of Climate Change on Insect Pests of Agricultural Importance

Koushik Sen*1, Arka Samanta1, Sruba Saha3 and Pratyusa Bakshi2

1Department of Agril. Entomology, 2Department of Agril. Extension, F/Ag, BCKV, Mohanpur, 741252 3Department of Genetics & Plant Breeding and Crop Physiology, PSB, Visva-Bharati, Sriniketan –

731236 *Corresponding Author eMail: [email protected], Mobile- +91-9800235762

In recent decades, climate change resultant global warming has become issue of serious concern

worldwide for existence of life on the earth. Global warming is one of the principal challenges

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confronting insects worldwide. Pest menace under the influence of climatic factors, at various stages of crop growth is one of the factors limiting agricultural productivity. Insect-pests of crop plants are the real candidates most affected by global climate change. It has been reported that, global climate warming may lead to altitude wise expansion of the geographic range of insect-pests, increased abundance of tropical insect species, decrease in the relative proportion of temperature sensitive insect population, more incidence of insect transmitted plant diseases through range expansion and rapid multiplication of insect vectors. Thus, with changing climate it is expected that the growers of crops have to face new and intense pest problems in the years to come. The climate change lead changes in insect-pest status will perilously affect agricultural production and the livelihood of farmers in the country where larger portion of work force is directly dependent on climate sensitive sectors such as agriculture. This envises an urgent need to modify crop protection measures with changed climate in order to attain the goal of food security of the nation.

Impacts of Climate change on Insect-Pests of Agricultural Importance

Insects are the most diverse group of animals on Earth estimated 6-10 million populations. An estimated 570,000 species may go extinct by the year 2100. Insects being poikilotherms, temperature is probably the single most important environmental factor influencing their behaviour, distribution, development, survival, and reproduction. Therefore, it is highly expected that, the major drivers of climate change i.e. elevated CO2, increased temperature and depleted soil moisture can impact population dynamics of insect-pests and the extent of crop losses, significantly. Impact of climate change on agriculture has been the most important research topic and intensively debated in recent times. The possible effects of changing climate on insects are, extension of geographical range of insect pests; in cooler latitudes global warming brings new species; increased over-wintering and rapid population growth; changes in insect-host plant interactions by speeding up pest growth rates which increases reproductive generations per crop cycle; a 2.4 to 2.7-fold increase in pesticide use by 2050; increased probability of pests developing faster resistance to pesticides; warmer winter temperatures would reduce winter kill, favouring the increase of pest populations; rising temperatures extend the growing season; increased risks of invasion by migrant pests; impact on arthropod diversity and extinction of species; changes in synchrony between insect pests and their crop hosts and natural enemy-pest interaction; introduction of alternative hosts as green bridges; emergence of new pests or

biotypes; change in feeding habits; reduced effectiveness of crop protection technologies.

Effect of Elevated Temperature on Insect Pests

Insects are particularly sensitive to temperature because they are stenotherms (cold-blooded). In general, insects respond to higher temperature with increased rates of development and with less time between generations. It has been estimated that with a 2oC temperature increase insects might experience one to five additional life cycles per season. Increased temperatures will accelerate the development of cabbage maggot, onion maggot, European corn borer, Colorado potato beetle-possibly resulting in more generations (and crop damage) per year. Increase in temperature in the range of 1°C to 5°C would increase insect survival due to low winter mortality, increased population buildup, early infestations and resultant crop damage by insect-pests under global warming scenario (Harrington et al., 2001). Natural enemy and host insect populations may respond differently to changes in temperature. Parasitism could be reduced if host populations emerge and pass through vulnerable life stages before parasitoids emerge. Hosts may pass though vulnerable life stages more quickly at higher temperatures, reducing the window of opportunity for parasitism. Skirvin et al. (1997) predicted that in hot summers coccinellids (Coccinella septempunctata) reduce aphids (Sitobion avenae) more strongly than in moderate summers. In Japan, warmer climate led to the northward migration of the green stinkbug (Nezara viridula) a major agricultural pest damaging soybean, rice, cotton and many other crops. The environmental factors like high temperature have been found affecting transgenic expression in Bt cotton resulting in reduced production of Bt toxins. This lead to enhanced susceptibility of the crops to insect-pests like bollworms viz., Heliothis virescens, Helicoverpa armigera and H. punctigera.

Effect of Elevated Carbon Dioxide on Insect Pests

Generally CO2 impacts on insects are thought to be indirect- impact on insect damage results from changes in the host crop. High CO2 concentrations have a fertilizer effect that can accelerate accumulation of above-ground biomass at the expense of other soil nutrients. Augmented photosynthesis and reduced photorespiration under enhanced CO2 levels generate plants with lower total nitrogen, higher ratios of carbon to nitrogen (C:N) and increased carbohydrate levels. This leads to greater root and shoot dry weight and greater root length and occasionally to improved yields. The decreased foliar nitrogen level reduces leaf nutritional quality, diminishing the value of foliage as a resource for insect herbivores. This has major implications for the concentration of defensive compounds in the leaves, the so-called secondary chemicals. Carbon-

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based secondary chemicals often increase and deter insect feeding. The overall effect of increased CO2 on insect herbivores is to decrease plant palatability because of decreases in nitrogen levels and increases in secondary chemicals.

Effect of Rainfall on Insect Pests

Distribution and frequency of rainfall may also affect the incidence of pests directly as well as through changes in humidity levels. It is being predicted that under the climate change, frequency of rainfall would decline while its intensity would increase. This would lead to heavy showers and floods on one hand and drought spells on the other. Under such situations, incidence of small pests such as aphids, jassids, whiteflies, mites, etc. on crops may be reduced as these get washed away by the heavy rains. Armyworm, Mythimna separata, reaches outbreak proportions after heavy rains and floods. Lever (1969) had analysed the relationship between outbreaks of armyworm and to a lesser extent

Spodoptera mauritia (Boisd.) and rainfall from 1938 to 1965 and observed that all but three outbreaks occurred when rainfall exceeded the average 89 cm. Aphid population on wheat and other crops was adversely affected by rainfall and sprinkler irrigation. In Sub-Saharan Africa, changes in rainfall patterns are driving migratory patterns of the desert locust (Schistocerca gregaria). Helicoverpa armigera damage severity showed higher November rainfall favoured higher infestation.

References Harrington, R., Fleming, R. and Woiwood, I.P. 2001.

Climate change impacts on insect management and conservation in temperate regions: can they be predicted? Agric. For. Entomol., 3, 233-240.

Lever, R.J.W. 1969. Do armyworm follow the rain? Wild Crops, 21, 351-352.

Skirvin, D. J., Perry, J. N. and Harrington, R. 1997. The effect of climate change on an aphid-coccinellid interaction. Global Change Biology, 3: 1-11.

83. NEMATOLOGY 14657

Nematodes Management in Protected Cultivation Brajnandan Singh Chandrawat*, Harshraj Kanwar and Dr. B. D. S. Nathawat

*Ph.D. Scholar, Department of Nematology RCA, (MPUAT), Udaipur and Division of Plant Pathology, Rajasthan Agricultural Research Institute, Durgapura, Jaipur (SKNAU, Jonner)

Protected cultivation practices can be defined as a cropping technique wherein the micro environment surrounding the plant body is controlled partially/ fully as per plant need during their period of growth to maximize the yield and resource saving.

Under protected cultivation technology used different types of manufactures: Green House, Plastic House, Glass House, Net House and Shade House etc.

Nematode Problem: High temperature and relative humidity within the greenhouses and poor plant hygienic conditions inside and outside the greenhouses provide ideal conditions for the introduction and rapid multiplication of insects, fungal, viral and bacterial diseases caused by plant parasitic nematodes (Esmenjaud, 2004).

Major Nematodes: Meloidogyne spp., Rotylenchulus reniformis, Pratylenchus spp., Aphelenchoides fragariae, Radopholus similis and Ditylenchus destructor. The ideal condition provided by protected cultivation and continuous availability of the host plant round the year often result in high population buildup of soil borne pathogens including plant parasitic nematodes. Continuous growing of same crop increase problem of soil borne pest and diseases including plant parasitic nematodes (Minuto et al., 2006) The problem of nematode after 3-

4 crops increases due to buildup of initial population in first crop and shortening life cycle of nematode due to higher temperature (Desaeger & Csinos, 2006).

Losses Caused by Nematodes under Protected cultivation: In India an average, a national loss of Rs 21,068.73 million has been estimated due to plant parasitic nematodes. The overall average annual yield loss in major horticultural crops due to nematodes goes up to 60% under protected cultivation.

Major Factors of Nematode Spreading: Mono cropping, Infested soil, seed & planting material, Irrigation water and Implements.

Nematode Management Practices: – Avoidance:- Sanitation, Remove infected

plant parts and debris, Maintain clean Greenhouse, Use nematode free soil and organic matter, Use nematode free planting material, Balance use of fertilizer, Balanced Irrigation and use soilless cultures (rock wool, perllite, Foam blocks etc.).

– Hot water Treatment: It is manly used for seed, transplanted crops, bulbs, rhizomes, root stock, cuttings, suckers, tubers and other planting materials.

Nematode Treatment

Root-knot Dip in hot water at 50oC for 30 min.

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Nematode Treatment

Root lesion Dip at 48oC for 30 min.

Burrowing At 50°C for 15 min

Stem & bulb At 43oC for 4 hours

Source: USDA-APHIS, Schedules for Plant Pests or Pathogens (T500)

– Soil treatment: This treatment should be done 15-20 days before seed sowing Prepare formalin solution (1.5 to 2%) in one container and drench the soil @ 4-5 litre of water per square meter soil surface to saturate it up to a depth of 15-20 cm. Cover the drench area with polythene sheet of 200 gauge. The cover (polythene) sheets remove after 15 days.

– Used Resistance Cultivars: Tomato:- S-120, Nematex, Hisar lalit, NT-3 and NT-7. Chilli:- Pusa jwala, Mohini, IPG-9E and NP-46A. Cucumber:- Long-green

– Soil amendments and Oil cakes use as nematicide

Oil cakes Toxic substance harm full to nematodes

Doses

Neem cake Azadirachtin, Salannin and Nimbin 1 kg/m2

Castor cake Isoleucine 2 kg/m2

Karanj cake Karanjin, Tannin and Trypsin 1.5 kg/m2

Mahua cake Saponin 1 kg/m2

Mustard cake

Gluco-sinolates and Methionine 2 kg/m2

FYM-2kg/m2 and Vermicompost-500gm/m2 (Rao, 2015).

– Bio-Agents:

Bio-Agent Rate of Application Application Method

Trichoderma harzianum

10 gm/m2 Soil treatment

T. harzianum and T. viride

5 gm/kg seed Seed treatment

Paecilomyces lilacinus

1 L/m2 (2×1012 cfu)

Cfu= colony formation unit

Soil treatment

Pochonia chlamydosporia

1 L/m2 (2×1012 cfu) Soil treatment

Pseudomonas fluorescens

2.5 gm/m2 Soil treatment

Pasteuria penetrans 3 gm/m2 Soil treatment

Method of Application

FYM Enrichment

1 ton FYM + 2 kg of each Pseudomonas fluorescens + Trichoderma harzianum + Paecilomyces lilacinus

Vermicompost Enrichment

1 ton Vermicompost + 2 kg of each Pseudomonas fluorescens + Trichoderma harzianum + Paecilomyces lilacinus

Neem Cake Enrichment

1 ton Neem cake + 2 kg of each Pseudomonas fluorescens + Trichoderma harzianum + Paecilomyces lilacinus

Soil Application of Enriched Mixture: 250 gm/m2

Chemical Management

Chemical Nature Rate of Application

Application Method

Dazomet Fumigant 50 gm/m2 Incorporated in bands and with Irrigation water

Metham sodium

Carbamates 40-50ml/m2

Incorporated in bands and with Irrigation water

Sodium Tetra Thio Carbonate (STTC)

Fumigant 15 ml/L2 Spot drenching

Cadusafos Organophosphates 20 ml/m2 Drip Irrigation

Carbofuran Carbamates 50 gm/m2 Applied around plant

Trizophos Organophosphates 15 ml/m2 Drip Irrigation

Oxamyl Carbamates 45 gm/m2 Incorporated in bands

Phorate Organophosphates 50 gm/m2 Incorporated in bands

Sharma et al., 2009

Pest and disease assume new proposition in protected cultivation of crops due to moderate climate and intensive cultivation. With this technology, the problems of diseases and nematodes had cropped up. Therefore, a fresh look into the dynamics of soil borne pathogens like root-knot nematodes has to be intensified. As the accrued loss due to these pests is tangible, proper attention is must for their management. There is further need to develop viable options for nematode management, including use of soil amendments, bio-control agents and chemicals.

References Desaeger, J. & Csinos, A. (2006). Root-knot nematode

management in double crop plasticulture vegetables. Journal of Nematology 38: 59-67.

Minuto, A., Gullino, M.L., Lamberti, F.D., Adabbo, T., Tescari, E. & Ajwa, H. Garibaldi (2006). Application of emulsifiable mixture of 1,3 Dichloropropene and chloropicrin against root knot nematode and soil fungi for green house tomato in Italy. Crop Protection 25: 1244-1252.

Rao M. S. (2015). Nematode management under protected cultivation. Current Science, Vol. 108,

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Infected roots Healthy roots

Management

Although chemical nematicides have been widely used in commercial agriculture to control nematodes, they are both highly toxic and very expensive. Control of root-knot nematodes involves a combination of growing resistant varieties where available, good cultural practices

and encouraging natural biological control.

Use of resistant varieties

Cultural practices such as deep ploughing, fallowing

Organic amendments can be applied to encourage the predatory nematode which in turn kill the nematodes.

Application methods of Biocontrol agent:

Trichoderma viride - The talc based T. viride formulation, is used as seed treatment @ 4g/kg of seed and soil application @ 2.5kg/ha for the management of nematodes.

Pseudomonas fluorescens - The bacterium, commercially available in talc formulation, is recommended as seed treatment @ 10g / kg of seed and soil application @ 2.5 kg along with 50 kg of farm yard manure per hectare for the management of nematodes.

85. EXTENSION EDUCATION 14848

ICAR Infra-Structure for Agricultural Development Hiralal Jana

Department of Agricultural Extension, College of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, Agricultural Farm-713101; Burdwan, West Bengal, India


Introduction: - “Agriculture is locomotive of our economy and a prosperous rural economy based on agriculture will ultimately make the nation prosperous.” -Sardar Vallabhbhai Patel. The Indian Council of Agricultural Research (ICAR) is an autonomous organization under the

Department of Agricultural Research and Education (DARE), Ministry of Agriculture and

Farmers Welfare, Government of India. Formerly known as Imperial Council of Agricultural Research, it was established on 16 July 1929 as a registered society under the Societies Registration Act, 1860 in pursuance of the report of the Royal Commission on Agriculture. The ICAR has its headquarters at New Delhi. The Council is the apex body for coordinating, guiding and managing research and education in agriculture including horticulture, fisheries and animal sciences in the entire country. With 111 ICAR institutes (ICARI-70+NB-6+NRC-15+PDs-12+ZPDs-8) and 61 agricultural universities spread across the country this is one of the largest national agricultural systems in the world. The ICAR has played a pioneering role in ushering Green Revolution and subsequent developments in agriculture in India through its research and technology development that has enabled the country to increase the production of food grains by 5 times, horticultural crops by 9.5 times, fish by 12.5 times, milk 7.8 times and eggs 39 times since 1951 to 2014, thus making a visible impact on the national food and nutritional security. It has played a major role in promoting excellence in higher education in agriculture. It is engaged in cutting edge areas of science and technology development and its scientists are internationally acknowledged in their fields

Sl. Abbreviation Full form Number

1. ICARI Indian Council of Agricultural Research Institute

70

2. NB National Bureau 6

3. NRC National Research Centre 15

4. PDs Project Directorates 12

5. SAU State agricultural University 61

6. DU Deemed University 5

7. CUFA Central University having Faculty of Agriculture

4

8. CAU Central Agricultural University 3

9. ZPD Zonal Project Directorate 8

10. KVK Krishi Vigyan Kendra 639

11. AICRP All India Coordinated Research Project

60

12. NP Network Project 21

13. STICARI Sub-Station of ICAR Institute 159

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States

STATES ICARI NB NRC PDs SAU DU CUFA CAU ZPD KVK AICRP NP STICARI

J & K 1 2 19 1 3

Punjab 2 2 1 20 2 5

Haryana 4 1 1 2 1 18 2 2 5

Rajasthan 3 2 1 6 1 42 4 3 9

Gujarat 2 5 28 2 9

Maharashtra 5 1 2 2 5 1 44 1 1 6

Goa 1 2

Karnataka 3 1 1 6 1 31 6 1 19

Kerala 5 3 14 3 10

Tamil Nadu 2 1 3 30 1 13

A. P. 2 3 23 1 13

Telengana 5 1 1 3 1 14 6 1

Orissa 4 1 33 2 7

West Bengal 3 3 1 1 18 1 14

Sikkim 1 1 4 1

Bihar 1 2 1 1 38 5

Jharkhand 3 1 24 2 3

Uttar Pradesh 12 2 5 2 2 1 1 68 12 7 6

Uttarakhand 2 2 2 13 1 4

H.P. 1 1 2 12 2 6

M.P. 4 1 3 1 47 10 1 5

Chattisgarh 1 2 20

North Eastern States

States ICARI NB NRC PDs SAU DU CUFA CAU ZPD KVK AICRP NP STICARI

Assam 1 1 25 2 4

Arunachal Pradesh

1 14 1

Nagaland 1 1 9 2

Manipur 1 9 1

Mizoram 1

Tripura 4 1

Meghalaya 1 1 5 2

Union Territories (UTs)

UTs ICARI NB NRC PDs SAU DU CUFA CAU ZPD KVK AICRP NP STICARI

Chandigarh 3 1

Delhi 3 1 2 1 1 1 4 1 1

D & D

D & N

Pondicherry 3

Lakshadweep 1 1

A&N 1 3

(Data based on ICAR Telephone Directory-2017)

Conclusion: Role of ICAR in Indian agricultural development is noteworthy, praiseworthy, remarkable and unquestionable. Though, now-a-days agriculture is losing its’ quite luster due to industrial sector and service sector’s speedy development. Everybody (mainly youth) is aspiring and chasing towards these two speedy

development sectors forgetting the importance of agriculture in their life, their families life, their country’s life as well as whole world’s life. But, it is true that even one day’s food shortage may bring disaster in country as well as whole world. Thus to push the new generation into realization of importance of agriculture in their life, few of

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motivational measures are to be taken. Here are the few motivational measures those needs ICAR’s consideration and implementation, so the role of ICAR will be more meaningful in nation building. (1) Shifting of emphasis is needed from production orientation to marketing orientation (2) Emphasis should be given on products diversification and value addition (3) ICAR institutes should be established in well-distributed manner to all states and union territories, it should be done on logical basis (4) Efforts of ICAR are needed to dignify agriculture (5) a prestigious award such as “Param Kisan Chakra” in

agriculture for the farmers should be introduced.(6) ICAR should introduce a award of excellence performance in agriculture as “Indian Nobel on Agriculture” (INA). (7) It is the proposal to ICAR to announce farmers of our country as “Krisi Sainik” or “Krishisena” (Agricultural Soldiers). (8) ICAR (as one of the largest national agricultural systems in the world) to place a paper in favour of agriculture for Nobel Prize to Swedish Academy.

“No race can prosper till it learns there is as much dignity in tilling a field as in writing a poem”.-Booker T. Washington

86. AGRICULTURAL ECONOMICS 13866

Constraints of Marine Fisheries in Tamil Nadu R. Thulasiram1 and P. Sivaraj2

1Assistant Professor, (Agricultural Economics), IIAT, Thuraiyur, Tamil Nadu 2Research Scholar, Department of Agricultural Extension, TNAU, Coimbatore, Tamil Nadu

Tamil Nadu Scenario

In Tamil Nadu, the fisheries of natural waters, including coastal and inland sources is under pressure due to high fishing intensities, pollution, open-access, manmade modifications, water abstraction, etc. and lead to problems in maintaining sustainable fisheries. In these waters sustainable exploitation of fish stocks can be achieved through community participation and co-management. Water availability and utilization in an effective manner has now become a matter of concern. Fisheries and aqua-culture provide for diversification as well as value addition in farming practices. In case of aqua-culture, scope exists for bringing more fish species with a focus on food fish, ornamental species and those with potentials for sport and tourism.

Lack of Resource Availability

Ready availability of inputs like fish seed, feed, fertilizer, medicines, other fisheries requisites, etc. is necessary for development. Establishment of' Aqua-shops, as a single window facility for the purpose is expected to bring about a major change in the sector. Fish Seed is a critical input for successful culture and culture-based practices. The projected annual requirement of carp seed is to the tune of 34,000 million carp fry, 10,000 million shrimp and 8,000 million scampi PL and two million sea bass. The fish feed requirements for freshwater aqua-culture by the end of next plan is estimated at 3.15 million tons for freshwater aqua-culture including grow-out and seed production and 0.23 million tons for brackish water aqua-culture.

Constraints in Fishing and Fish Trade

The constraints in fishing, trade and facilitations are discussed according to the merits of the

problems. In general, the problem in production or supply of fish surpasses the problem in the trading of fish. The selling problem was faced little by the fishermen compared to production. Among the fishing constraint, the problem was more with operational expenditure and less with in lean season and fish feed. The major constraints felt by the fisher folks are hike in fuel price, inadequate fuel subsidy, shortage of crew, poor quality fishing fleets and declining catches. However a few fishermen had a problem of access to finance, fluctuations in returns, loss in business, fish feed and lean season. These problems indicated high production cost, labour shortage and risk involved in the fishing profession.

Since there exists a close sense of belonging between fishing industry and the fish trading industry, it is inevitable to know the problem of producer in the selling of fish which is a complementary to the fish production sector. The main problem in the selling of fish by the fishermen was forced sale of fish. Because of the tie-up arrangements the fishermen were in the clutches of auctioneer and have no say simply at the receiving end in the price realisation. Next important problems in selling were price fluctuations, packaging and transportation and collision among intermediaries. When there is high price, it is obvious that the fishermen are benefited but there are cases of low price, particularly when the catch has higher proportion of low value fish. However, there are also problems due to packaging and transportation, since fish being highly perishable has to be iced and immediately transferred to distant places, even during odd hours. This has resulted in increased marketing cost with a mark-down in the price realised by fishermen. Collision among traders also found to be a negative effect in few

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cases of fishermen. To have a holistic solution, the lapses in the

facilities provided for the fishermen also should be considered. Lack of dry docking and fish net mending facilities are found to be an acute problem. This is one of the frequent problems in fishing, so to say the fishing units are always submerged in corrosive marine water are often get damaged affecting fish operation. This was the highlight of the problem, followed by this lack of institutional finance, supply of fishing devices,

processing and storage, sanitation and emergency medical facilities are the other major problems. It is noteworthy to mention the value addition in the domestic trade was almost nil, except in few cases the spoiled one are sundried in an unhygienic way. This has resulted in fishermen could not cater distant market for want of processing and thus realising a reduced net price. Lack of credit facilities often leave them in the clutches of intermediaries with the prolonged indebtedness.

87. ECONOMICS 14786

Inflation: Type, Factor, Effect and Remedies Y. Latika Devi1, Jenny Kapngaihlian2 and T. Arivelarasan3

1Research Scholar, 2Teaching Associate, Department of Agricultural Economics, College of Agriculture, PJTSAU, Hyderabad-500030, Telangana, India

3Research Associate, ABM Division, ICAR-National Academy of Agricultural Research Management, Hyderabad-500030, Telangana, India

What is Inflation?

Inflation is a rise in the general level of prices of goods and services in an economy over a period of time. When the general price level rises, each unit of currency buys fewer goods and services. Consequently, inflation also reflects erosion in the purchasing power of money – a loss of real value in the internal medium of exchange and unit of account in the economy. The annualized inflation rate in India was 3.7% as of 2015. Inflation in India is said to be very sensitive to the agricultural production and particularly the food grains production.

The Indian method for calculating inflation, the Wholesale Price Index, is different from the rest of world. Each week, the wholesale price of a set of 435 goods is calculated by the Indian government. Since these are wholesale prices, the actual prices paid by consumers are far higher.

Types of Inflation

1. Creeping Inflation: This is also known as mild inflation or moderate inflation in which prices rise 3 per cent annually. Mild inflation is good for the economy as it drives economic expansion.

2. Walking Inflation: This type of strong or pernicious, inflation is between 3-10% a year. It is harmful to the economy because it heats up economic growth too fast.

3. Galloping Inflation: If mild inflation is not check and if it is uncontrollable it may assume the character of galloping inflation. In this the inflation rate is more than 10 % a year. The economy become unstable and the government leaders loss credibility.

4. Hyperinflation: It is a stage of very high inflation in which the rate of inflation cross 50% a month. In fact, most example of

hyperinflation have occurred when the government printed money recklessly to pay for war.

Factors of Inflation

1. Demand factors: It basically occurs in situation when the aggregate demand in the economy has exceeded the aggregate supply. It could further be described as a situation where too much money chases just few goods.

2. Supply factors: Supply side inflation is a key ingredient for the rising inflation in India. The agricultural scarcity or the damage in transit creates a scarcity causing high inflationary pressures.

3. Domestic factors: Developing economies like India have generally a lesser developed financial market which creates a weak bonding between the interest rates and the aggregate demand. This accounts for the real money gap that could be determined as the potential determinant for the price rise and inflation in India. The supply of money grows rapidly while the supply of goods takes due time which causes increased inflation.

4. Cost- Push Effect: Essentially, this theory states that when companies are faced with increased input costs like raw materials and wages, they will preserved their profitability by passing this increased cost of production onto the consumer in the form of higher prices.

Effect of Inflation

Inflation effects both the economy of a country and its social conditions as well as the political and the moral lives of its inhabitants. However, the economic effects of inflation are stated and described below:

1. Erodes purchasing power: Inflation decrease

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the purchasing power of currency due to a rise in the prices across the economy.

2. Effects on Distribution: Inflation has the effect of redistributing income because prices of all factors do not rise in the same proportion. Entrepreneurs stand to gain more than wage earners or fixed income groups. Speculators, hoarders, black marketers and smugglers stand to gain on account of windfall profits.

3. Debtors and Creditors: Debtors borrow from creditors to pay the latter along with the rate of interest at some future date. Changes in the price level affect them differently at different times. During inflation when the prices rise (and the real value of money goes down), the debtors pay back less in real terms than what they had borrowed, and thus, to that extent they are gainers. On the other hand, the creditors get less in terms of goods and services than what they had lent and stand to lose to that extent.

Remedies

1. Increase Production: The following measures should be adopted to increase production: a) One of the foremost measures to control

inflation is to increase the production of essential consumer goods like food, clothing, kerosene oil, sugar, vegetable oils, etc.

b) If there is need, raw materials for such products may be imported on preferential basis to increase the production of essential commodities,

c) Efforts should also be made to increase productivity. For this purpose, industrial peace should be maintained through agreements with trade unions, binding them not to resort to strikes for some time,

2. Price Control: Price control and rationing is another measure of direct control to check

inflation. Price control means fixing an upper limit for the prices of essential consumer goods. They are the maximum prices fixed by law and anybody charging more than these prices is punished by law. But it is difficult to administer price control.

3. Rationing: Rationing aims at distributing consumption of scarce goods so as to make them available to a large number of consumers. It is applied to essential consumer goods such as wheat, rice, sugar, kerosene oil, etc. It is meant to stabilise the prices of necessaries and assure distributive justice. But it is very inconvenient for consumers because it leads to queues, artificial shortages, corruption and black marketing. Keynes did not favour rationing for it “involves a great deal of waste, both of resources and of employment.”

4. Credit Control: One of the important monetary measures is monetary policy. The central bank of the country adopts a number of methods to control the quantity and quality of credit. For this purpose, it raises the bank rates, sells securities in the open market, raises the reserve ratio, and adopts a number of selective credit control measures, such as raising margin requirements and regulating consumer credit.

5. Demonetisation of Currency: However, one of the monetary measures is to demonetise currency of higher denominations. Such a measures is usually adopted when there is abundance of black money in the country.

6. Increase in Taxes: To cut personal consumption expenditure, the rates of personal, corporate and commodity taxes should be raised and even new taxes should be levied, but the rates of taxes should not be so high as to discourage saving, investment and production.

88. ECONOMICS 14823

Unemployment – Types, Consequences and its Remedies Jenny Kapngaihlian1, Y. Latika Devi2 and T. Arivelarasan3

1Teaching Associate, 2Research Scholar, Department of Agricultural Economics, College of Agriculture, PJTSAU, Hyderabad-500030, Telangana, India

3Research Associate, ABM Division, ICAR-National Academy of Agricultural Research Management, Hyderabad-500030, Telangana, India

Unemployment is a situation where the person who is willing to work fails to find a job that earns hima living. Unemployment means lack of employment. In simple words, unemployment means the state of being unemployed. Unemployment records in India are kept by the Ministry of Labour and Employment of India. According to NSS (66th round) Report from Ministry of Statistics and Programme

Implementation, Government of India, published on 2013, Kerala has the highest unemployment rate, while Rajasthan and Gujarat has the least unemployment rate among major States of India. The national average for unemployment rate stands at 50.

In India, many factors have led to unemployment. Some of the factors are as follows:

1. Over population.

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2. Seasonal nature of certain works. 3. Economic fluctuations 4. Extensive automation and use of IT which has

replaced man power.

Types of Unemployment in India

There are various types of Unemployment. Some of them are discussed below:

1. Seasonal unemployment: Seasonal unemployment results from seasonal fluctuations in demand. Agriculture is a seasonal occupation. Thus, a sizeable portion of the work force remains unemployed for at least 5 months in a year.

2. Industrial unemployment: Workers are forced to be unemployed due to saving devices.

3. Educational unemployment: It arises when a large number of educated people are unemployed or unable to secure a job.

4. Technological unemployment: It refers to a situation when people have been put out of work by the introduction of superior technology in their idea of operation.

5. Disguised unemployment: It is a situation in which a person appears to be employed, but enough work is not available. Too many workers are engaged in doing a small job.

Ways to Measure Unemployment

1. Usual Status: This measure estimates the number of persons that may be said to be chronically unemployed. This measure generally gives the lowest estimate of unemployment especially for a poor economy because only a few can afford to remain without work over a long period of time.

2. Current Weekly Status (CWS): This estimate reduces the reference period i.e. the period for which data is collected to one week. According to this estimate a person is said to be employed for the week even if he is employed only for a day during that week.

3. Current Daily Status (CDS): The reference period here is a day. It counts every half day's activity status of the respondent over the week.

Consequences of Unemployment

1. Wastage of Productive Resources 2. Loss of Resource Efficiency 3. Adverse effect on Saving and Capital

Formation

4. Source of Exploitation 5. Leads to Inequalities of Income 6. Burden on Government 7. Change in Work Attitude 8. Adverse effect on Individual’s Personality 9. Adverse Social and Political Effects

Prevention or Remedies of Unemployment

1. About 70 per cent of Indian lives in rural areas, so the government should promote agriculture and efforts should be made in order to ensure that the agriculture and allied activities are profitable. This will reduce the movement of rural people to urban areas in search of job.

2. The Government should promote agro-based industries by giving skill oriented training to the rural youth so that it will provide a means of self-employment and generation of employment in the rural India.

3. Self-employment should be encouraged by Government and various NGO’s by providing financial assistance to various entrepreneurs.

4. The country should promote industrialization so that more job opportunities can be created for the workers. Thus, focus should be on heavy industries that employed thousands of man powers of varied skills.

5. The growth of population must be checked and family planning programmes must be properly implemented.

Conclusion: Unemployment is one of the alarming problems in both rural and urban India. Seasonal unemployment is the main setback of rural India, while educational, industrial and technological unemployment are found in urban India. Unemployment will not only affect the socio-economic conditions of the people but will also curtail the methods of use and employing of productive resources for obtaining income. Further, the savings and capital formation process can also be disturbed whereby creating burden to the government and overall development of the country as well. As a result, unemployment cannot be solved by a single strategy but by a multi-pronged and well integrated approach.

Reference Socio-Economic Profiles & Inter State Comparison of

Some Major States in India. Economic Survey, Government of India. 2012-13. p – 276.

89. ECONOMICS 14846

Farmer Producer Organisation Payal Jaiswal1 and Shyam Prakash Singh2

1Department of Agricultural Economics, Indira Gandhi Agricultural University, Raipur, C.G. 2Department of Agricultural Economics, B.C.K.V., Nadia, West Bengal.

Collectivization of producers, especially small and marginal farmers, into producer organisations has

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emerged as one of the most effective pathways to address the many challenges of agriculture but most importantly, improved access to investments, technology and inputs and markets. Department of Agriculture and Cooperation, Ministry of Agriculture, Govt. of India has identified farmer producer organisation (FPO) registered under the special provisions of the Companies Act, 1956 as the most appropriate institutional form around which to mobilize farmers and build their capacity to collectively leverage their production and marketing strength.

FPO is one of the important initiatives to mainstream the idea of promoting and strengthening member-based institutions of farmers. As per the concept, farmers, who are the producers of agricultural products, can form groups and register themselves under the Indian Companies Act. These can be created both at State, cluster, and village levels. It is aimed at engaging the farmer companies to procure agricultural products and sell them. Supply of inputs such as seed, fertilizer and machinery, market linkages, training & networking and financial and technical advice are also among the major activities of FPO. The Small Farmers’ Agribusiness Consortium (SFAC) has been nominated as a central procurement agency to undertake price support operations under Minimum Support Price (MSP) for pulses and oilseeds through the FPO’s.

Characteristics of Farmer Producer Organization

An Organization will be called a Farmer Producer Organization, if it is formed by a group of primary producers

It is a registered body and a legal entity

Producers are primary shareholders in the organization

It deals with business activities related to the primary produce/product/ related inputs

It works for the benefit of the member producers

Portions of profit are shared amongst the producers and the balance goes to the share capital or reserves.

It has minimum shareholding members numbering 50 at the time of registration. However, the shareholding membership will have to be increased over a period of 3 years to a sustainable level.

Objective

The primary objective of mobilising farmers into member-owned producer organisations, or FPOs, is to enhance production, productivity and profitability of agriculturists, especially small farmers in the country. The participant farmers will be given the necessary support to identify appropriate crops relevant to their context,

provided access to modern technology through community-based processes including Farmer Field Schools; their capacities will be strengthened and they will be facilitated to access forward linkages with regard to technology for enhanced productivity, value addition of feasible products and market tie-ups. Farmers will be organised into small neighbourhood informal groups which would be supported under the programme to form associations/organisations relevant to their context including confederating them into FPOs for improved input and output market access as well as negotiating power.

Principles

FPO principles are the guidelines by which FPOs will put their values into practice.

1st Principle: Voluntary and Open Membership

2nd Principle: Democratic Farmer Member Control

3rd Principle: Farmer-Member Economic 4th Principle: Autonomy and Independence 5th Principle: Education, Training and

Information 6th Principle: Co-operation among FPOs 7th Principle: Concern for the Community

Strategy for Promoting Farmer Producer Organizations

Identification of potential FPOs among successful Watershed Development projects, Wadi Projects and their Federations.

Identification of natural clusters of farmers groups to facilitate formation of FPOs

Close involvement of stakeholders such as NGOs, Banks, Govt. line departments, commodity Boards, Corporations, Corporate, functional Universities, cooperatives, Federations, Trade bodies, etc. for identification, promotion, nurturing, development, capacity building, evaluation etc. of FPOs

Development of Best Practices, Pilot Projects and Success Stories for wider publicity and field level replication

Adoption of mission mode with periodic qualitative and quantitative milestones with timelines

Wide publicity to the FPO Scheme through print, electronic media and adopting other Mass Communication Strategies vii. Conventional/non-conventional publicity and awareness creation methods

Launching of pilot projects, action research projects, experimental projects, field trials etc. to learn and understand various models of FPOs and successful strategies for wider replication

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90. AGRICULTURAL ENGINEERING 14824

Contour Trenching and Contour Stone Wall for the Water Conservation in Hilly Regions

Md. Majeed Pasha and Vinodkumar S.

Department of Agricultural Engineering, UAS, GKVK, Bangalore-560065 *Corresponding Author eMail: [email protected]

INTRODUCTION: Contour trenching and contour stone bund is one of the practices in which it is used as a soil conservation measure to intercept the runoff. Contour trenches are constructed across the slope on sloping land. The deep percolation and seepage contribute to the soil moisture in the downstream reaches. The trenches and stone bunds form a barrier that slows down water runoff, allowing rainwater to seep into the soil and spread more evenly over the land. This slowing down of water runoff helps with building-up a layer of fine soil and manure particles, rich in nutrients. From the perspective of climate change adaptation, contour stone bunds protect the land from heavy rain in years with high rainfall. In drought years, they improve rainwater harvesting, retention and infiltration into the soil, increasing the amount of water available to plants and guaranteeing the harvest.

Advantages: The main advantages of contour trench and stone bund are to break the runoff velocity and intercept the runoff. Rain water is collected into these trenches and percolates into the lower soil strata resulting in soil enrichment moisture content. If the lower portion of catchment is under bunding system, then contour trenches also protect the bund against breaching by the runoff generated from upper part.

The cross section of trenches should rarely exceed 0.3×0.3m2. It is designed to collect and convey the runoff. These are arranged in staggered form Side slopes in range of 1:1to 0.5:1 and the Height of bund is fixed

Classification of Contour Trenching

1) Graded trenches, 2) Staggered trenches These are suited for areas having high annual

rainfall. The cross section of the trenches is about 30*30cm. The side slope is about1:1 to 0.5:1. Staggered trenches these are constructed for shorter length these are arranged in staggered for (not in straight line) these trenches have shorter length and arranged in row along the contour with interspaced between them. Vertical interval between two trenches is decided on basis of expected runoff. Alternate rows of trench are located directly below one another. Cross sectional area of these trenches is designed to collect the intense storm during 5 to 10 return period.

Slope category Horizontal Interval Vertical Interval

Gentle 5-10 13.5-19.5

Medium 10-25 6-13.5

Steep >25 1.25

Plate 1: Staggered Trenches

Plate 2: Contour Stone wall

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Conclusion: A minimum amount of labor on upkeep is required for constructing contour trenching and Stone bunds need to be usually implemented by the community, with development projects supporting the technical material and logistics aspects. Economic success requires optimal spacing of stone bunds based on the type of construction, materials transport cost, and how labor is organized. Soil and water conservation Increase local resilience to climate

change Under water limiting conditions, the stone bunds are efficient measures to improving soil water content through runoff control, which can reach 59% in plots with barriers alone, and even 84% in plots with barriers + organic matter. When rainfall is erratic, the stone bunds contribute to conserving more moisture in the soil for longer, which helps to alleviate water stress during dry spells.

91. AGRICULTURAL ENGINEERING 14825

Crop Cultivation and Management in Green House Md. Majeed Pasha and Vinodkumar, S.

Department of Agricultural Engineering, UAS, GKVK, Bangalore-560065 *Corresponding Author eMail: [email protected]

INTRODUCTION: Soil solarization is a method of heating soil by covering it with transparent polythene sheeting during hot periods to control soil borne diseases. The technique has been commercially exploited for growing high-value crops in diseased soils in environments with a hot summer (maximum daily air temperatures regularly exceeding 35°C). Examples include control of verticillium and fusarium diseases in vegetable crops in Israel, control of verticillium dahlias in pistachio orchards and control of chickpea and pigeon pea wilt in India. Soil mixes used for greenhouse production of potted plants and cut flowers are highly modified mixtures of soil, organic and inorganic materials. When top soil is included as a portion of the mixture, it is generally combined with other materials to improve the water holding capacity and aeration of the potting soil. Many greenhouses do not use topsoil as an additive to the soil mixes, but rather use a combination of these organic and inorganic components as an artificial soil mix. When managed properly as to watering and fertilization practices, these artificial mixes grow crops that are equal to those grown in top soil.

Media Preparation for Greenhouse Production

The media used in greenhouse generally have physical and chemical properties which are distinct from field soils.

A desirable medium should be a good balance between physical properties like water holding capacity and porosity.

The medium should be well drained.

Medium which is too compact creates problems of drainage and aeration which will lead to poor root growth and may harbour disease causing organisms.

Highly porous medium will have low water and nutrient holding capacity, affects the plant growth and development.

The media reaction (pH of 5.0 to 7.0 and the soluble salt (EC) level of 0.4 to 1.4 dS/m is

optimum for most of the greenhouse crops).

A low media pH (<5.0) leads to toxicity of micronutrients such as iron, zinc, manganese and copper and deficiency of major and secondary nutrients while a high pH (>7.5) causes deficiency of micronutrients including boron.

A low pH of the growth media can be raised to a desired level by using amendments like lime (calcium carbonate) and dolomite (Ca-Mg carbonate) and basic, fertilizers like calcium nitrate, calcium Cyanamid, sodium nitrate and potassium nitrate.

A high pH of the media can be reduced by amendments like sulphur, gypsum and Epsom salts, acidic fertilizers like urea, ammonium sulphate, ammonium nitrate, mono ammonium phosphate and aqua ammonia and acids like phosphoric and sulphuric acids.

It is essential to maintain a temperature of the plug mix between 70 to 75ºF. Irrigation through mist is a must in plug growing. Misting for 12 seconds every 12 minutes on cloudy days and 12 seconds every 6 minutes on sunny days is desirable.

The pH of water and mix should be monitored regularly.

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Fig.1 Different crops in Green house

Gravel Culture

Gravel culture is a general term which applies to the growing of plants without soil in an inert medium into which nutrient solutions are usually

pumped automatically at regular intervals. Haydite (shale and clay fused at high temperatures), soft- or hard-coal cinders, limestone chips, calcareous gravel, silica gravel, crushed granite and other inert and slowly decomposing materials are included in the term “gravel”. The more important greenhouse flowering crops include roses, carnations, chrysanthemums, gardenias, snapdragons, lilies, asters, pansies, annual chrysanthemums, dahlias, bachelor buttons and others.

Advantages

1. Throughout the year four to five crops can be grown in a greenhouse due to availability of required plant environmental conditions.

2. The productivity of the crop is increased considerably.

3. Superior quality produce can be obtained as they are grown under suitably controlled environment.

4. Gadgets for efficient use of various inputs like water, fertilizers, seeds and plant protection chemicals can be well maintained in a green house.

5. Effective control of pests and diseases is possible as the growing area is enclosed.

6. Percentage of germination of seeds is high in green houses. The acclimatization of plantlets of tissue culture technique can be carried out in a greenhouse.

7. Agricultural and horticultural crop production schedules can be planned to take advantage of the market needs.

8. Different types of growing medium like peat mass, vermiculate, rice hulls and compost that are used in intensive agriculture can be effectively utilized in the greenhouse.

9. Export quality produce of international standards can be produced in a greenhouse.

92. FOOD SCIENCE 13831

Parboiling: A Big Share of the Global Rice Processing Industry Butti Prabhakar1, J. Srinivas2 and M. Vinaya kumari3

1Teaching Associate, College of Food Science & Technology, Rudrur, Nizamabad, Telanagana-503188, 2Ph.D. Scholar, Dept. of Horticulture, Vegetable Science, SKLTSHU, Hyderabad-500030, And

4Ph.D Scholar, Dept of AEABM, Shiats, Allahabad, UP. *Corresponding Author eMail: [email protected]

INTRODUCTION: In world paddy production, Asia’s share is more than 90 percent. Paddy is a primary food grain crop of India. Rice Production during 2015-2016 was 470.89 million metric tons. India stands in second largest producer of rice with 105 million metric tons after China. More than 50 percent of country’s population depends fully or partially on rice as it constitutes the main

cereal food crop of the diet. Generally, the majority of the population of a developing country consumes parboiled rice. This is especially true on the Indian Sub-continent where it originated a long time ago. Parboiling of rice seems to be increasing day by day, because the growth rate of populations in these countries is higher and a major part of the food value of what they consume

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comes from rice. Processing of rice by parboiling goes back to ancient times. Parboiling of rough rice before milling, which is believed to have originated in India. Parboiled rice is popular in India, Bangladesh, and Sri Lanka. In Sri Lanka about 75% of the rice is parboiled before milling. It has been found that parboiling remedies the defect "sun checking", which is the most important factor associated with grain breakage during milling.

Flow Chart

Flow chart: Parboiled rice

Process

Parboiled rice is rice precooked in the husk. Gelatinization of the starch, followed by its partial retrogradation, are the two principal changes that result from parboiling. Parboiling is a hydrothermic treatment given to rough rice, and consists of soaking, steaming and drying. During the parboiling process, starch gelatinization takes place, a thermochemical reaction between the starch granules and heat energy in the presence of water. Final gelatinization temperature ranges from 55° to 79°C. This starch gelatinization changes the physicochemical properties of rice which affects the other processing operations of storage, milling, cooking and eating quality.

Nutritional Value of Parboiled Rice

Cereals are deficient in lysine but oats and rice are rich in lysine. Parboiling results in partial heat decomposition of the B complex vitamins but facilitates their diffusion into the endosperm. Thus, although parboiled brown rice has lower vitamin B content than raw brown rice, its milled rice is richer in these vitamins at the same degree of milling as raw milled rice However, no movement of protein and oil occurs. Parboiled rice is easier to dehull and more resistant to breakage during milling. Parboiling can make even waxy rice translucent. The milled rice absorbs water more slowly than raw rice, and the grain is commonly presoaked before cooking so that cooking time will approach that of raw milled rice. The heat-treatment coagulates proteins, thereby reducing losses of protein during milling. The parboiling effect during drying is more evident in the wet-season crop than in the dry-season crop, as the latter has a lower moisture content at harvest. Little decomposition of water-soluble

vitamins occurs during hot-sand drying.

Quality of Parboiled Rice

Codex standards for parboiled rice as follows, organic extraneous matter such as foreign seeds, husk, bran, fragments of straw, etc. shall not exceed 1.5% m/m for husked parboiled rice and 0.5% m/m milled parboiled rice. Inorganic extraneous matter such as stones, sand, dust, etc. shall not exceed 0.1% m/m husked parboiled rice and 0.1% m/m milled parboiled rice. Parboiled husked rice with a length/width ratio of 3.1 or more and milled rice or parboiled milled rice with a length/width ratio of 3.0 or more. Parboiling results in a harder and more translucent grain.

Cooking Qualities of Parboiled Rice

Parboiled milled rice is less shiny than raw rice. It takes a longer time to cook. It expands more in volume on cooking, and the expansion is more in girth than length. Parboiled rice cooks more fluffy and dry. Parboiled milled rice seems to have a lower apparent amylase content than raw rice. The loss of nutrients in the cooking water is also less in parboiled rice. Parboiling converts chalky, no translucent grain to uniformly translucent grain. It has been observed, however, that when chalky-grain raw rice is cooked, it tends to show more splitting of cooked grain than no chalky rice, which produces a smooth grain - a characteristic desired by Sri Lankan consumers. Rice bran contributes to hardness. Starch retrogratation and starch complexation with lipids lead to hardness. Superheated steam can minimize hardness of rice in parboiling. Harder gel consistency is associated with harder cooked rice and this feature is particularly evident in high-amylose rice. High amylose grains cook dry, are less tender, and become hard upon cooling.

The stale flavor of stored milled rice comes from carbonyl compounds formed from fat oxidation on the surface of milled rice, such as propanal-acetone, 1-pentanal, and 1-hexanal. Increase in 1-hexanal level is to be greatest and is to be in proportion to storage period. Fat deterioration occurs as the oil in the open cells on the surface of milled rice becomes exposed to microbial inoculation in contrast to the intact endosperm of brown and rough rice. Some of other characteristics also affect on consumer acceptability like dark colour, hard cooking. Mycotoxins may incorporate into parboiled rice during soaking and loss of antioxidants during parboiling leads rancid which in turn leads to undesirable smell during storage.

Value Added Products Made from Parboiled Rice

Puffed rice: It is made from parboiled paddy and used as whole for eating.

Flaked rice: It is made from parboiled rice and used in many preparations.

Parched rice: It is made from parboiled rice and is easily digestible. In India, about 4-5

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percent of total supplies of rice is used as parched rice.

Others: Idli rava, dosa mix and extruded products like vermicelli are also prepared.

Conclusion: The value of parboiled rice has

been increased day by day. Nutritional values and milling qualities are improved in parboiled rice. Parboiling of paddy provides economic status of rural women at small and medium scale level.


High Pressure Processing in Food Industry Manoharachari D.

UAS, Dharwad *Corresponding Author eMail: [email protected]

High Pressure Processing (HPP) is a cold pasteurization technique by which products, already sealed in its final package, are introduced into a vessel and subjected to a high level of isostatic pressure (300–600MPa/43,500-87,000psi) transmitted by water. Pressures above 400 MPa / 58,000 psi at cold (+ 4ºC to 10ºC) or ambient temperature inactivate the vegetative flora (bacteria, virus, yeasts, moulds and parasites) present in food, extending the products shelf life importantly and guaranteeing food safety. High Pressure Processing respects the sensorial and nutritional properties of food, because of the absence of heat treatment, and maintains its original freshness throughout the shelf-life.

Principle of HPP: Principles of High Pressure Processing Hydrostatic pressure is generated by increasing the free energy; this can be achieved by physical compression during pressure treatment in closed system by mechanical volume reduction. Usually HPP accompanied by a moderate increase in temperature, called the adiabatic heating, which depends on the composition of the food product being processed (Balasubramaniam et al., 2004; Hogan et al., 2005).

Process: In pascalization, food products are sealed and placed into a steel compartment containing a liquid, often water, and pumps are used to create pressure. The pumps may apply pressure constantly or intermittently. The application of high hydrostatic pressures (HHP) on a food product will kill many microorganisms, but the spores of some bacteria may need to be separately treated with acid to prevent their reproduction. Pascalization works especially well on acidic foods, such as yogurts and fruits, because pressure-tolerant spores are not able to live in environments with low pH levels. The treatment works equally well for both solid and liquid products. During pascalization, the food's proteins are denatured, hydrogen bonds are fortified, and non-covalent bonds in the food are disrupted, while the product's main structure remains intact. Because pascalization is not heat-based, covalent bonds are not affected, causing no change in the food's taste. High hydrostatic pressure can affect muscle tissues by increasing

the rate of lipid oxidation, which in turn leads to poor flavor and decreased health benefits. Because hydrostatic pressure is able to act quickly and evenly on food, neither the size of a product's container nor its thickness play a role in the effectiveness of pascalization. There are several side effects of the process, including a slight increase in a product's sweetness, but pascalization does not greatly affect the nutritional value, taste, texture, and appearance. As a result, high pressure treatment of foods is regarded as a "natural" preservation method, as it does not use chemical preservatives.

Fig 1: High Pressure Process Mechanism

Application of HPP in food industry and its Advantages: HPP system consists of one or more HPP vessels and a pressure intensifier system. For HPP, typical pressures up to 6000 bar (87000 psi) are used to destroy undesired spoilage microorganisms in foods, even at room temperature. By this processing technology, degradation of vitamins and flavor is reduced to a minimum. A fundamental advantage of HPP is that the high pressure is applied in a homogeneous manner over the entire product, unlike heat processing, where temperature gradients are unavoidable. Increased product shelf life - even for food which is sensitive to heat Low-temperature preservation method. No loss in product quality compared to heat No loss in product quality compared to heat pasteurization Enhanced food safety due to inactivation of spoilage organisms and relevant food borne pathogens Processing in final consumer packaging is possible Additive-free preservation of

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food by using only pressure Production of “natural”, safe value-added food with a superior quality Homogenous effect of HPP: Results are independent of product size and geometry Waste-free and environmentally friendly, sustainable technology – only water and electricity are needed. Pascalization stops chemical activity caused by microorganisms that play role in the deterioration of foods. The treatment occurs at low temperatures and does not include the use of food additives. From 1990, some juices, jellies, and jams have been preserved using pascalization in Japan. The technique is now used there to preserve fish and meats, salad dressing, rice cakes, and yogurts. An early use of pascalization in the United States was to treat guacamole. It did not change the guacamole's taste, texture, or color, but the shelf life of the product increased to thirty days, from

three days without the treatment. However, some treated foods still require cold storage because pascalization does not stop all enzyme activity caused by proteins, some of which affects shelf life.

Fig 2: HPP in food processing


Aseptic Packaging of Foods Pranjal S Deshmukh

Assistant Professor, Sau Vasudhatai Deshmukh College of Food Technology, Amravati, MS *Corresponding Author eMail: [email protected]

Aseptic packaging can be defined as the filling of a commercially sterile product into sterile containers under aseptic conditions and scaling of the containers so that re-infection is prevented. The term “aseptic” implies the absence or exclusion of any unwanted organisms from the product, package or other specific areas, while the term “hermetic” is used to indicate suitable mechanical properties to exclude the entrance of microorganisms into a package and gas or water vapor into or from the package. Asepsis preserves food by preventing microbial contamination from the raw state to the finished product.

Aseptically packaged products require:

1. Sterilization of the starting materials 2. Sterilization of the packaging materials 3. Maintenance of sterile surroundings while

forming and filling the pack 4. The production of packaged units which are

scaled efficiently to prevent any re-infection.

Currently these are two specific fields of application for aseptic packaging:

1. Packaging of pre-sterilized and sterile products a) E.g. Milk and dairy products, Desserts,

Fruits and vegetable juices, Soups, Sauces 2. Packaging of a non-sterile product to avoid

infection by microorganisms a) E.g. Fresh products such as fermented

dairy products like yoghurt

Aseptic processing allows better use of packaging materials and systems because unlike conventional canning, aseptic processing cause

less thermal damage to the product and less stress on the packaging. Moreover, it allows the use of materials other than the traditional metal can or glass jar.

Producing a sterile product in a continuous process involves three steps:

1. Heating it to raise the temperature to the desired level

2. Passing the product through a temperature holding section for a predetermined time

3. Cooling product as rapidly as possible to a temperature of 35°C or less prior to filling.

Whilst, the hazards connected with aseptically packaged foods are not considered to be different from in-pack sterilization, the risks are different. Consequently, low acid foods (pH<4.5) should receive a heat process which is equal in effect to the ‘botulinum cook’. Usually the UHT range is used because the spoilage organisms, mainly yeasts and moulds are relatively more heat sensitive.

Packaging materials that have been developed for aseptic processing are:

1. Preformed containers, principally tubes and cups which are sterilized, filled and closed with a heat-sealed lid, usually coated foil.

2. Vertical pouch forming systems 3. Lidded thermoform/fill/seal systems fed from

a reel. 4. Systems starting from plastics beads which

are extruded into a parison which is blown into a container and subsequently filled and closed.

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5. Bag-in-box systems.

95. FOODS AND NUTRITION 14671

Adolescent Nutrition Kirti M. Tripathi

Krishi Vigyan Kendra, Bulandshahr, SVPUA&T, Meerut

Adolescence is a transitional stage in human life. In our society where priorities have been based on morbidity and mortality rates, adolescents have been overlooked by health planners. Now government is recognising their presence, care and counselling are coming to the limelight. Studies have shown that two-third of adolescent girls are malnourished and anaemic.

Puberty sets in a little earlier in tropical countries. Precocious puberty is diagnosed when signs of secondary sexual characters are seen before the age of eight years in girls and before the age of nine years in boys.

The growth is influenced due to nutrition, genetic factor and hormonal factor. Malnutrition among adolescents is common because many of them consume less food due to lack of time as they are engaged in a period of stressful studies in the school. They usually avoid carrying tiffin boxes and thus consume fast food and soft drinks, which affect their health severely. Some of the adolescents have psychological problems like anorexia nervosa and bulimia nervosa.

Adolescent eating habits:

1. Eating behaviour- Facts which need attention are as follows. a) Variability in nutrient consumption is

common. Someday they tend to consume high calorie food and the other day very low calorie food.

b) They usually tend to miss meals like breakfast, lunch etc. Many avoid taking tiffin boxes during their college or school.

c) Fast food provides some nutrients, but it is not balanced diet at all. Moreover consuming refined and packaged food items causes stomach to upset. Food additives like ajinomoto and certain colouring agents and dyes are anti-nutrients and destructive in nature.

d) Soft drinks kill appetite and promote skipping of meals which is dangerous in long run and can cause many health ailments thereafter.

e) Start of alcohol consumption is dangerous turn and lead to alcohol related accidents and crimes.

f) Likes and dislikes towards food, like aversion to roots and tubers, steamed food items etc. and liking for fried and fast foods.

g) Low intake of some nutrients especially

micronutrients like calcium, iron, iodine, Vit A, E, C, zinc copper etc. is now being highlighted. Zinc supplementation has shown to improve weight and height gain in those with low birth weight and malnutrition.

1. Eating Healthy Campaign: Following are the principles recommended for eating healthy call. a) Ensuring a balanced diet from food

groups every day.

Food guide triangle for day to day choice of food

Serving size of various food groups.

S. no.

Food groups Serving size

Serving/day

1. Cereals, pulses, bread and other cereal based products

1 slice or 1 oz.

6-10

2. Vegetables half cup 3-5

3. Fruits 1 piece of 200 gm

2-3

4. Milk and milk products 1 cup 2-3

5. Meat group 2 oz. 2-3

6. Fats, oils 2-3 tsp sparingly

7. Sugars To taste sparingly

1 cup= 240 ml, 1 glass= 200ml, 1 katori= 150ml, 1 ladle= 30ml, 1 oz= 30 ml, 1 tbsp= 15ml, 1 tsp= 5 ml

b) Variety should be maintained within each food group, e.g., not always the same vegetables.

c) The adolescent boy should eat as much as

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the father eats (2400 kcal) and the adolescent girl should eat a little more than what the mother eats (2100 kcal).

d) Beta-carotene, Vit A, Vit C, folic acid, iron, iodine, zinc are essential. Weekly iron during adolescence is a advantageous intervention.

e) Small and frequent meals are recommended for better growth.

The concept of eating healthy should be suggested with patience, perseverance and a sense of humour. Parents are always more reliable than others and can choose the foods and drinks they buy, cook and store.

The adolescent’s food habits are laid down in the family and the family appears to be the one and the main influence. The other is the peer group, the evolving independent personality and the society in general. Adolescence is a transitional stage with upset food habits, but soon they settle down and re-establish the eating behaviour of the family and the work out a compromise set of food habits with the partner. Thus, they decide the eating habits of the future families.

Reference Elizabeth, K.E. 2010. Nutrition and Child

Development. pp 355-358

96. DAIRY SCIENCE 14466

Dairy and Dairy Food Packaging Trends Dr. Chopade A. A. and Shri. Patil R. V.

Department of Animal Science and Dairy Science, MPKV Rahuri

Packaging is defined as enclosing food to protect it from tampering or contamination from physical, chemical and biological sources. Packaging is an indispensible vehicle to deliver products to consumers. Now a day’s consumer requires food that are fresh, mildly preserved, convenient and ready to serve. In response to changing consumer lifestyles, large retail groups and food service industries have introduced highly competitive mix of marketing & trading strategies which depends on quality of packaging material and technology employed. New concepts of active packaging, intelligent packaging and nanotechnology offers innovative solutions which plays an important role for improving or monitoring food quality & safety and extending shelf-life (Dobrucka and Cierpiszewski, 2014).

Controlled and Modified Atmosphere Packaging

Modified atmosphere packaging (MAP) is the replacement of air in a pack with a single gas or mixture of gases (mainly CO2, N2 and O2) whereas controlled atmosphere storage refers to the constant monitoring and adjustment of gas levels within gas tight stores or containers. It provides an optimum atmosphere for increasing the storage length and quality of food. The MAP technique has proven to be useful in prolonging the shelf life of cheese samples in terms of microbiological and sensorial aspects. Shelf life of ready-to-serve pizza increased up to 45 days by MAP, compared to conventional air pack (15 days) (Preeti et al., 2011).

Active Packaging

Active packaging is an innovative packaging technology that incorporate certain additives into packaging film or within packaging containers by which package, product, and environment interact to prolong shelf life or enhance safety or sensory

properties as well as maintain the quality of the food product. Ahvenainen (2003) has given a broad classification of active packaging techniques as i) Absorbing System ii) Releasing System iii) Other System- Self-heating aluminum or steel cans and containers, Self-cooling aluminum or steel cans and containers.

i) Absorbing System

1. Oxygen scavenger (absorber)- It removes oxygen from inside of package. Materials such as iron incorporated into package structures that chemically combine and effectively remove oxygen from the inner package environment. The system is based on the oxidation of iron and ferrous salts to form stable oxide. One gram of an iron will react with 300 cc of O2. Various other materials can also be used as oxygen scavengers like sulfites, boron, photosensitive dyes and enzymes. Classification of oxygen absorber depends upon activation mechanism (auto activated, water activated and UV activated), scavenger form (sachet, label and extrudable component) and reaction speed (fast, medium and slow effect). Probiotic yoghurt added with glucose oxidase maintain low levels of dissolved O2 and cell viability of B. longum and L. acidophilus d up to 21st day of storage at refrigerated temperature. UHT milk packaged with oxygen scavenging film shown to reduction in dissolved oxygen content (23% -28%) and stale flavor volatiles during storage.

2. CO2 scavenger- The CO2 scavenging sachet absorb the occluded CO2 which otherwise cause the package to burst if not removed during. Carbon dioxide absorbers contain material such as calcium hydroxide, sodium hydroxide, potassium hydroxide, calcium oxide and silica gel. The mechanism is as

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given below: CaO + H2O Ca(OH)2 Ca(OH)2 +CO2 CaCO3 + H2O. It has applications in coffee, battered goods and cheese.

3. Ethylene absorber- Ethylene accelerates ripening and reduces the shelf life. Thus its control plays an important role in prolonging the postharvest life of many types of fresh produce during storage. Potassium permanganate can be used as Ethylene absorber which oxidizes ethylene to carbon dioxide and water. Use of Activated carbon for ethylene adsorption and subsequent breakdown by metal catalyst (pelladium) can also be done.

4. Moisture absorber- Silica gel, molecular sieves, natural clay, calcium oxide, calcium chloride and modified starch can act as moisture absorber. Placing humectants between two layers of a plastic film which is highly permeable to water vapour can be done to control excess water. Controlling relative humidity (RH) using deliquescent salts (such as CaCl2, MgCl2) in packaging materials can regulate moisture.

5. Absorbers of off flavours- Undesirable odours and flavours are produced as the food material is broken down. Inclusion of cellulose triacetate, acetylated paper, citric acid, ferrous salt, activated carbon, clays and zeolites in to packaging material absorbs off flavours and odours. They are also incorporated to improve the organoleptic quality of the product.

6. Lactose and cholesterol removal- Beta-galactosidase (lactase) can be covalently attached to surface-functionalized low-density polyethylene films which act as active packaging materials. It is used for people suffering from lactose intolerance and thus used in milk and other dairy products. Immobilized cholesterol reductase can be incorporate in to the packaging material to reduce cholesterol.

ii) Releasing System

1. Antimicrobial releasing system- Antimicrobial packaging is done to control or even prevent the growth of undesired or spoilage microorganisms by releasing antimicrobial substances. Practices like adding a sachet containing antimicrobial substance into the package, dispersing bioactive agents in the packaging film, coating bioactive agents on the surface of the packaging material comes under this system. It works by extending the lag phase and reducing the growth phase of microorganisms. Class of antimicrobial compounds includes acid anhydride, antibiotic, bacteriocin, organic acid, polysaccharide etc.

2. Antioxidant release- Antioxidant compounds scavenge radicals by inhibiting initiation and breaking chain propagation or suppressing

formation of free radicals by binding to the metal ions, reducing hydrogen peroxide, and quenching superoxide and singlet oxygen. Compounds such as herbs and aromatic plants, natural vitamins (vitamin C and vitamin E) and polyphenol are used for this purpose Whole milk powder with multilayer active packaging film containing α-tocopherol showed delayed lipid oxidation.

3. Carbon dioxide emitter- In certain food products high CO2 levels (10-80%) are helps in reducing microbial growth and extending shelf life. Such systems are based on either ferrous carbonate or a mixture of ascorbic acid and sodium bicarbonate.

4. Ethanol emitter- Ethanol denatures the proteins of molds and yeasts at high concentration and it exhibits antimicrobial effects even at low levels. Ethanol vapor also exert an antistaling effect in addition to its antimold properties.

iii) Other System

1. Self-heating and self-cooling- Self heating employs calcium or magnesium oxide and water to generate an exothermic reaction. When the bottom of can is pushed the salt reacts with water and heat is produced during the exothermic reaction that heats the product. Self-cooling involves the evaporation of an external compound that removes heat from contents to cool the drink the lower part is twisted, breaking the seal, leading to expantion of liquid and its evaporation which reduces the temperature of beverage to 16°C.

2. Edible coating- These are consumable films which provide supporting structures and protective layers to food. These films and coatings guarantee the fresh appearance, firmness and shine, thus adding value to the product. Various substances suitable for the development of edible coatings are hydrocolloids based on proteins of animal or plant sources (e.g. whey, soy, corn, legumes) or polysaccharides (e.g. cellulose derivates, alginates or starches), lipids (e.g. waxes, shellac, fatty acids) or even synthetic polymers (e.g. polyvinyl acetate) (Cargi et al., 2004). It can be used to enhance the nutritional value by carrying basic nutrients that lack or are present in low amounts. Edible coating as carriers of antimicrobial compounds is another potential alternative to enhance the safety of fresh-cut produce.

3. Intelligent packaging- This systems give information on product quality directly (freshness indicators), about package and its headspace gases (leak indicators), and the storage conditions of the package (time temperature indicator). Intelligent packaging could be defined as a packaging system that is capable of carrying out intelligent functions (sensing, detecting, tracing, recording and

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communicating) to facilitate decision making to extend shelf life, improve quality, enhance safety, provide information and warn about possible problems.

4. Time temperature indicators (TTIs)- Product safety and quality is affected by variation in temperature and thus its monitoring is needed during storage. TTIs are devices that show an irreversible change in a physical characteristic, usually color or shape, in response to change in preset temperature. They continuously monitor, record and indicate the overall influence of temperature history on the product. The response is made to chemical, enzymatic or microbiological changes. Depending upon response mechanism they can be available as partial history and full history indicator.

5. Radio frequency identification tags- Radio frequency identification (RFID) is a system that uses radio waves to track items wirelessly and give information regarding quality of product. RFID makes use of tags or transponders (data carriers), readers (receivers), and computer systems (software, hardware, networking, and database).

6. Bio Sensor- They are compact analytical devices that detect, record and transmit information pertaining to biological reactions. It consist of bioreceptors (such as enzymes, antigens, microbes, hormones and nucleic acids) and transducers (electrochemical, optical, calorimetric). There are two biosensor systems commercially available: (1) Toxin Guard (2) Food Sentinel System (based on immunological reactions and detects contamination) Nanotechnology- Nanotechnology is defined as ‘control or

manipulation of matter at the atomic, molecular, or macromolecular level, which affects functional behavior.’ Nano composites are main and major invention of nanotechnology in which nanomaterials were used to improve the barrier properties of plastic wrapping for foods and dairy products. Detection of chemicals, pathogens, and toxins in foods can also be done by nanosensors. Nanovesicles have been developed to simultaneously detect E. coli 0157:H7, Salmonella spp., and Listeria monocytogenes.

7. Eco-friendly packaging- It can play a key role in food waste avoidance to protect human health, environment and in preserving natural resources. The ideal packaging material should not possess any environmental issues and should have recycling potential. Research in the production of biodegradable packaging material lead to development of eco-friendly packaging materials. Essential qualities for eco-friendly material includes reduce, recycle, renew, reuse and repurpose.

References Ahvenainen, R (2003). Active and intelligent

packaging: An introduction. In: Ahvenainen R (Ed). Novel Food Packaging Techniques, Woodhead Publishing Ltd., Cambridge, UK. pp 5-21.

Dobrucka R and Cierpiszewski R. (2014). Active and intelligent packaging food- Research and Development- A review. Pol J Food Nut Sci, 64 (1):7-15.

Preeti S, Wani AA and Goyal GK. (2011). Prolonging the shelf life of ready-toserve pizza through modified atmosphere packaging: Effect on textural and sensory quality. Food and Nutrition Sci, 2(7):785792.

97. DAIRY SCIENCE 14701

DCAD and Milk Fever Khwairakpam Ratika1 and Rajkumar James singh2

1Division of Dairy Cattle Nutrition, National Dairy Research Institute, Karnal-132001 2Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly-243122

INTRODUCTION: Milk fever affects most of the dairy cows. Milk fever occurs when the blood calcium concentrations fall below 5mg/dl which is quite low as compared to normal concentrations. i.e. 8- 12 mg/dl. The blood calcium is maintained homeostatically but due to lactational drain, its concentrations fall below the normal concentrations and impair muscle and nerve function. There are about 23 grams of calcium in 10 litres of colostrum, and when this is added to the normal amount of calcium needed for maintenance, the needs of the cow can be more than 10 times the supply of calcium in her bloodstream. Milk fever cows are more susceptible to other health disorders like mastitis,

ketosis, retained palcenta, displaced abomasum and uterine prolapse. DCAD is one of the nutritional approaches used to combat these health issues of dairy cows.

DCAD

Dietary cation anion difference (DCAD) is the difference between certain cations (Na+ and K+) and anions (Cl- and S--), in milliequivalents. The concept of DCAD is based upon the maintenance of desirable acid base status. Cations like Na+, K+, Ca2+ and Mg2+ in the diet promote a more alkaline (higher blood pH) metabolic state which has been associated with an increased incidence of milk fever. Anions like Cl- and S2- promote

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more acidic metabolic state (lower blood pH) that is associated with a reduced incidence of milk fever.

How it Works?

DCAD affects acid base status and Ca metabolism of the animal. Anionic salts (negative DCAD) cause metabolic acidosis, lower blood pH and elevate blood calcium concentrations. Metabolic acidosis increases tissue parathyroid receptors responsiveness to parathyroid hormone. So, when there will be low blood calcium level parathyroid hormone will be released and will increase renal reabsorption of Ca. It will also promote the synthesis of 1, 25- dihydroxycholecalciferol from 25-hydroxycholecalciferol in the kidney, as a result, bone Ca resorption and intestinal Ca absorption increase. One the other hand, parathyroid receptors present in bone are less functional at high blood pH (metabolic alkalosis). A ration formulated using typical forages and concentrate will always have positive DCAD. So anion salts such as magnesium sulphate, calcium sulphate, ammonium sulphate, calcium chloride, ammonium chloride and magnesium chloride, can be used to achieve negative DCAD.

Calculation of DCAD

The most commonly used equation or the calculation of DCAD is

(Na + K) – (Cl + S) = DCAD in mEq/kg

DCAD is normally expressed using milliequivalents of major cations and anions. Milliequivalents are calculated by multiplying the content of each element in the diet by a conversion factor. The DCAD equation and conversion to milliequivalents can be combined as follows into one step:

[(sodium x 435) + (potassium x 256)] - [(chloride x 282) + (sulfur x 624)] = mEq/kg

A negative DCAD diet contains more equivalents of anions than cations, a zero DCAD diet contains equal equivalents, and a positive DCAD diet contains more cation equivalents.

DCAD for Close up Dry Cows

For dry cows three weeks from calving, a negative DCAD is desirable. This increases blood calcium levels prior to freshening. Lowering the DCAD level to -36 to -55 meq / lb of TRDM (equivalent to -8 to -12 meq / 100g of TRDM or -80 to -120 meq / kg of TRDM) helps increase blood calcium, preventing milk fever, reducing udder edema, and leading to fewer retained placentas and displaced abomasums.

DCAD for Lactating Cows

Due to higher incorporation of rapidly fermentable carbohydrates in their diets, lactating cows tend to experience increased levels of acid build up, both ruminally and in their blood. These rations also tend to support less rumination, which reduces the production of salivary bicarbonate, the major buffer of acids in both the rumen and blood. During periods of heat stress, panting and reduced rumination increase the loss of bicarbonate, which reduces blood pH and blood buffering capacity. For just-fresh cows and lactating cows, a highly positive DCAD level is recommended, between +159 and +204 meq / lb of total ration dry matter or TRDM (equivalent to +35 to +45 meq / 100g of TRDM or +350 to +450 meq / kg of TRDM). This level helps improve feed intake and milk production without affecting milk fat and protein percentages.

Monitoring of Urine pH

If anionic salts are being used, urine pH can be monitored to determine their effectiveness or to prevent problems from too much anionic salt. Urine pH can be monitored using pH paper or a pH meter. If urine pH is greater than 7.0, anionic salts should be added. Urine pH less than 5.5 indicates that anionic salt intake is excessive and should be reduced. A urinary pH within the range 5.5 to 6.2 is accepted as an indicator of successful administration of anionic salts.

98. VETERINARY 14613

Snake Poisoning in Animals K. Jayalakshmi and M. Sasikala1

Department of Veterinary Medicine and 1Department of Veterinary Pathology Veterinary College and Research Institute, Orathanadu-614 625, Thanjavur

Tamil Nadu Veterinary and Animal Sciences University

Snake bite in animals generally occurs while grazing or hunting. The most cases have been reported in dog, horse and other species. Generally, most of the snake venoms produce two type of toxicity i.e. Neurotoxicity, Cardiotoxicity or Haematotoxicity. The Neurotoxicity is mostly produced by enzymatic portion of the venom.

The most common poisonous snakes are coral snake, cobra, krait, mombas, pit viper, rattle snake, viper, adder, sea snake, sea krait and bird snake.

The toxicity of snake bite is depends on

1. Toxicity and quantum of venom injected 2. Ratio of animal i.e. size of the animal and

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