Bangladeshj. crop sci. 2008,19 (1): 21-26

EFFECT OF AGE OF SEEDLINGS AND DATE OF TRANSPLANTING

. ON THE PERFORMANGE OF BORO RICE UNDER SRI METHOD

M.Z. Hossainl, M.A.R. Sarkar and A.K.M.M. lslam

Depaftment of AgronomYBang I adesh Ag ricultu ral U n ive rsity

Mymen si ng h-220 2, Bangl ade sh

(ReceiVed on 11 March, 2008)

Abstract

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh AgriculturalUniversity, Mymensingh -2202 in order to find out the effect of age of seedlings and date of transplanting on theperformance of Boro rice (cv. BRRI dhan29). Thr6e levels of age of seedlings viz.;i)$-day old seedlings ii) 12-

day old seedlings iii) 45-day old seedlings, and eilht dates of transplanting viz.; i) 1 December ii) 15 Decemberiii) 30 December iv) 15 January v) 30 January vi) 15 February vii) 2 March and viii) 16 March were arranged in arandomized complete block design. Single seedlings were transplanted hill-' with a spacing of 30 cm r 30 cm. ltwas observed that age of seedlings exerted significant effect on yield and yield components except number ofnon-effective tillers hill-l, panicle length and 1000-grain weight. The 12-day old seedlings produced the highestgrain yietd (6.36 tha-1) than 8-day and 45-day old seedlings. The lowest grain yield (5.54 t ha-') was obtainedfrom 45-day old seedlings. The highest grain yield was obtained due to the highest number of effective tillershill'l and the highest number of grains panicle''. The date of transplanting had significant effect on cropcharacters, yield components and yield except number of non-effective tillers hill-', panicle length, 1000-grainweight and straw yield. The highest grain yield (8.46 t ha'') was obtained when the crop was transplanted on 15

January but the lowest grain yield (1.il t ha'') was produced when seedlings were transplanted on 16 March.Grain yield was not significantly affected by the interaction between age of seedlings and date of transplanting.

Key words: Boro rice, age of seedling, date of transplanting, SRl.

lntroduction

Bangladesh is predominantly a rice growing country but here its yield level is farbelow than many other rice growing countries of the world. Average yield of rice in

Bangladesh is only 2.6 t ha-'(BBS, 2004) while that in other countries like China, Japan,Korea and Egypt are5.7,5.9,7.5 and 7.3 t ha-', respectively (Choi,2000). This is mainlydue to a wide gap between potential yield and actual yield in our country. lmproper andpoor management practices mainly account for such a wide yield gap that might beminimized through improved management techniques. Under this context the System ofRice lntensification (SRl) might be studied as a management practice for minimizing theyield gap in our country. SRI can raise irrigated rice yields to approximately double thepresent world average (Uphoff, 2003). SRI raises productivity not by relying on externalinputs, e.g.; new grains and fertilizer, but by changing the way farmers manage their riceplants, soil, water and nutrients (Uphoff ,2007).

There are many reasons for this low yield. The most important are hightemperature (40-50 "C), low humidity at the time of transplanting, use of seedlings ofunsuitable age etc. The correct age of seedlings used for transplanting is of primaryimportance for uniform stand and seedlings establishment, as Padalia (1980) stated "halfof the success of rice cultivation depends upon the seedlings". Nursery management is

lAdditional Agriculture Officer, DAE, Khamarbari, Farmgate, Dhaka

22 TRANSPLANTING OF BORO RICE UNDER SRI METHOD

an integral part of transplanted rice (Lal and Roy, 1996). For optimum yield, age ofseedlings at transplanting of a particular variety in a particular season may not besuitable for other varieties in other seasons. So it is very important to find out theoptimum age of seedlings of a particular variety in a particular season. Suitable date oftransplanting is the most important factor for maximizing yield of Boro rice. Yield of ricealso differs due to growing environment, such as different locations, seasonalfluctuations, different dates of transplanting etc. (Sarker, 2002). Crop growth anddevelopment period may be affected by the major environmental factors such astemperature and day length (Van Heemst, 1986). Temperature, apart from the day lengthand solar radiations, plays a vital role in rice plants during later stages of crop growth(Nishiyma, 1976). High temperature (3240'C) at harvesting results in decrease inpanicle weight and increase in the number of empty grains in ten cultivars (Zakria et al.,2002). Morita et al.(2002) noted a decrease in average grain weight at high temperatureduring day and night. Thanomthin et al. (2002\ observed a decrease in spikelet due tohigh temperature of 30 "C from 800-1600 h at heading stage. lt was observed that rootgrowth was adversely affected by higher temperature while at lower temperature rootdevelopment was severely restricted (Ogasawara et al., 1998). Rice seedlingsexperience low temperature when transplanted at early date in Boro season and theirvegetative growth in terms of plant height and tillering becomes retarded.

It is important to select suitable age of rice seedlings contributing towardsincreased rice production and resolve the problem posed by transplanting date. Thepresent endeavour was, therefore, made to determine the appropriate seedlings age anddate of transplanting for obtaining higher yield of Boro rice (cv. BRRI dhan29) under SRImethod

Materials and Methods

The experiment was conducted at the Agronomy Field Laboratory, BangladeshAgricultural University, Mymensingh during the period from October 2006 to June 2007with a view to finding out the effect of age of seedlings, date of transplanting and theirinteraction on yield of Boro rice cv. BRRI dhan29. The experimental site belongs to OldBrahmaputra floodplain (AEZ 9) with medium high land and loamy soil. The pH of the soilwas 6.81. The experiment comprised three levels of age of seedlings viz.; i) 8-day oldseedlings ii) 12-day old seedlings iii) 45-day old seedlings, and eight dates oftransplanting viz.; i) 1 December ii) 15 December iii) 30 December iv) 15 January v) 30

January vi) 15 February vii) 2 March and viii) 16 March, which were arranged in arandomized complete block design with three replications. Healthy grains of BRRIdhan29, a high yielding Boro rice variety, were used as planting material. The land waspuddled thoroughly by ploughing and cross-ploughing with a country plough andsubsequently leveled by laddering. The size of unit plot was 4.0 m x 2.5 m. Each plot wasfertilized with 120,60,40, 10 and 5 kg N, PzOs, K2O, S andZn, respectively in the form ofurea, triple super phosphate (TSP), muriate of potash (MOP), gypsum and zinc oxide,respectively. Except urea all other fertilizers were applied at final land preparation. Ureawas top dressed in three equal splits a|20,35 and 50 days after transplanting (DAT). Theseedlings were transplanted within 30 minutes after careful uprooting. One seedling wastransplanted in each hill maintaining a spacing of 30 cm x 30 cm. All interculturalpractices were done as and when necessary as per SRl. The first weedings were done at20 DAT and subsequent weeding was done at 15 day intervals up to 70 DAT.

HOSSAIN ef a/

lndividual plots were harvested at full maturity (i.e.; when 90% of the grainsturned golden yellow) on different dates ranging from tVlay to July 2OO7 and yield r6tat"Ocharacters were recorded. Five-plants plot-l were selected randomly for recording data onyield components such as total tillers hill-1, effective tillers hill-1 Lnd number

-of grains

panicle-'. The harvested crop was then threshed, cleaned, sundried and weigniO torecord the yields of grain and straw al 14o/o moisture content. The yields of griin andstraw were then converted into t ha-1. The recorded data were analyied using-"Analysisof variance" technique and mean differences were adjudged by Duhcan's NJw MultipleRange Test (Gomez and Gomez, 1984).

Results and Discussion

Effect of age of seedlings

Age of seedlings showed remarkable influence on all the crop characters, yieldcomponents and yield of Boro rice except panicle length, 1000-grain weight, number ofnon-effective tillers hill-' and straw yield (Table 1). The tallest plant (93.56 cm; was foundin 12-day old seedlings and the shortest plant (90.02 cm) was found in g-day oldseedlings, which was statistically identical to 45-day old seedlings. The 12-day oldseedlings produced the highest number of effective iillers hill-1 (30.45) and the lowestnumber of effective tillers hill-] (25.16) was recorded at 45-day old seedlings. The 12-davold seedlings significantly gave the highest number of grains panicle-1 1l1l.l2) and aS-day old seedlings produced the lowest number of grains panicle-l (114.2g). Wang et al.(2002) reported that transplanting of younger seedlings had ; positive effect onincreasing number of tillers and promoting the early occurrence of maximum tillers but99eO seedlings consequently failed to produce the increased number of effective tillers.Roy ef al. (1992) reported that number of grains panicle-1 decreased with the increase ofage of seedlings.

The highest qrain yield (6.36 t ha-1) was found in 12-day old seedlings and thelowest grain yield (5.34 t ha-') was found at 45-day old seedlings. The increised grainyield in 12-day old seedlings occurred due to increase in the number of effective tillershill-' and number of grains panicle-l. The highest (13.49 t ha-1) and the lowest biologicalyield (12.04 t ha-1; were recorded al 12- day and +b- Oay old seedlings, respectively. Thehighest harvest index (Hl) was obtained in 12-day old seedlings followed in oroei oy gand 45-day old seedlings. According to Uphoff (2001), the best age to transpllntseedlings depended on a number of factors that affect the length of the plant'sphyllochron - temperature, day length, soil moisture, soil and plant nutrient status,spacing etc. Considering all the factors, he concluded that transplanting seedlings of g-12days under SRI technique performed the best, Still the scientists in different dorners ofthe world opined that the seedlings age can be 5-6 days and even up to 14 days. ltdepends on the prevailing temperature of the growing site which actually determiner tn"growth of the seedlings (Stoop et al., 2002; CllFAD, 2OO2). For better performance underSRl, seedlings must be transplanted before fourth phyilochron i.e.;'having two smallleaves (Uphoff, 1999). ln the present study both groups of seedlings did not reach thefourth phyllochron stage before planting. lt was also observed that |Z-aay old seedlingsestablished faster and started tillering faster than 8-day old seedlings. This might be apossible explanation of observing better performance by younger seedlings.

24 TRANSPLANTTNG OF BORO R|CE UNDER SRI METHOD

Table 1. Effect of age of seedlings on yield and yield components of Boro rice

Age ofseedlings

Plantheight(cm)

No. ofeffective

tillershilll

No. ofnon-

efiectivelillers hilll

No. ol

totaltillershifl

Paniclelength(cm)

No. ofgrains

panicle'l

No. ofsterile

spikeletspanicler

1000-grain

weight

b)

Grainyield

(t ha't)

Strawyield

(t ha'r1

Biologidyreld

(t har)Hr f6)

8-dav old 90.02 b 27.83 b 3.70 31.54 b 22.25 122.12b 33.37 b 21.35 6.08 b 6.91 12.9S b 46.65 a

12-dav old 93.56 a 30.45 a 3.70 34.15 a 22.74 127.12a 31.37 c 21.37 6.36 a 7.13 13.49 a 45.91 b

4S-dav old 91.37 c 25.16 c 3.83 28.99 c 22.M 114.29 c 37.95 a 21.36 5.54 c 6.50 12.Mc 45.83 b

Level of

siqnificance0.01 0.01 NS 0.01 NS 0.01 0.01 NS 0.01 NS 0.01 0.01

cv (%) 3.30 7.03 22.79 7.24 4.77 11.00 7.31 1.81 6.18 14.07 6.01 1.53

Effect of date of transPlanting

Crop characters, grain yield and its components were significantly affected by

date of transplanting exce[t number of non-effective tillers hill-l, panicle length and 1000-

grain weight (TablJ2). Seedlings transplanted on 15 January significanfly produced the

highest grain vieiJ lii.+o t ha:1) foilowed in order by seedrings transptanted on 30

December, 30 Januaiy, 15 December, 15 February, 1 December, 2 March and 16 March'

respectively. The toweit grain (1.64 t ha-1) was found from the seedlings transplanted on

16 March. The highest inLidence of spikelet sterility with the lowest number of effective

fi;;ili i *"i" ri"inly responsible foi the lowest grain yield at late transplanting on 16

March. The present findings are in conformity with that of lslam et al- (2004). Seedlings

transplanted on 15 January produced the highest values for most of the plant characters

viz. effective tiuerJ ;itii;ili tillers hiil-l, nuirber of grains panicle-l and sterile spikelets

piri.i":i'il" il"st number ot "tr"liiul

tirr"rt hill-lJnd number of grains panicle-l were

observed on 16 March transplanting. The seedlings transplanted.gn.l5 January gave the

highest straw yietJ 1s.06 t ha-1) "n-

biotogical yield (18.12 t ha-') while the lowest straw

and biorogicar yierds were found on 16 March transpranted crop. The highest harvest

index (Hl) was found on 15 January transplanting, which was statistically identical to 30

December transpranting and the rbwest harvest index (Hr) was found on 16 March

transplanting, which wal statistically identical to,lranspl?lting. ?,1-,,2

March' The panicle

length, 1000-Grain weight and num-ber of non-effective tillers hill-l were not significantly

affJcted by the date of transplanting (Table 2)'

tnteraction effect of age of seedlings and date of transplanting

plant height, number of grains panicle-1 and number of sterile spikelets panicle'1

were ,ignifi."niti atrected by the interaction effect of age of seedlings and date of

transplanting oaote 3).The tallest plant (101.56 cm) was found when 12- day old

seedlings were transplanted on 15 January followed by the same age of seedlings

transpranted on 30 January and 15 February. The rowest prant height (79.10 cm) was

found when 8-day old seedlings were transplanted on 16 March' The 12-day old

seedrings transpranted on 15 January gave the highest number of grains panicle'l

(163.33J white the lowest one (150.33) was found in 45-day old seedlins:l:?Tu,,,T:"^o,on

16 March. The yield retarding factors like number of sterile spikelets panicle-' was the

highest in 45-day old seedlings transplanted on 16 March.

HOSSAIN ef at 25

Table 2. Effect of date of transplanting on yield and yield components of Boro rice

dissimilar letter differ significantly (as per DMRT).NS = Not significant.

Table 3. lnteraction effect of seedlings age andyield components of Boro rice

date of transplanting on yield and

ln a column, figures with same lette(s) or without lette(s) do not differ significantly whereas figures withindissimilar lefter differ significantly (as per DMRT).NS = Not significant

The interaction effect of age of seedlings and date of transplanting was notsignificant on number of effective, non-effective and total tillers hill-l, panicle length, 1000-grain weight, grain yield, straw yield, biological yield and harvest index (Table 3).However, although not significant, numerically the highest grain yield (8.90 t ha-')was

Date oltransplanting

Plant

heightlcml

No. olefleclive

tillers hill'l

No. ol non-

eflectivetillers hilll

l,lo. oltotal

tillers hillr

Paniclelength

{cml

No. ofgrains

Danicle{

No. ol slerilespikeletsoanicle't

1000-grain

weiohl {ol

Grainyield

(t har)

strawyieldIt hail

Biologicalyield

ft har)Hrf/")

I December 90.70 de 27.44 d 3.88 31.32 d 22.42 137.nbc 20.55 e 21.50 6.15 d 7.07 c 13.22e 46.52a15 December 91.72cd 34.33 c 3.M 37.77 c 22.33 138.88 abc n33e 21.28 7.37 c 8.56 b 15.93 c 46.14 ab

3O December 92.88 bcd 38.33 b 3.55 41.88 b n.28 140.'14 c 25.66 d 21.43 8.10 b 9.14 ab 17.24b 46.79 a

15 January 96.32 a 40.33 a 4.00 44.33 a 23.38 151.77 a 20.55 e 21.50 8.46 a 9.66 a 18.12 a 46.75 e

30 January 94.63 abc 35.11 c 3.88 38.99 c 21.85 143.33 ab 22.Me 2',t.2s 7.82b 9.14 ab 16.96 b 46.13 ab

l5 Februarv 94.95 ab 24.77 e 3.M 28.21 e 22.35 107.66 d 44.88 c 21.33 6.41 d 6.84 c 13.2s d 45.65 b

2 March 88.70 e 12.22t 3.88 16.10 f 22.47 86.22e 53.77 b 21.31 2.01 e 2.40d 4.41 e 45.59 b

16 March 83.281 10.00 o 3.88 13.88 r 21.65 63.88 I 63.66 a 21.29 1.dil 1.97 d 3.61 I 45.54 b

Level olsidnilicence 0.01 0.01 NS 0.01 NS 0.01 0.0r NS 0.01 0.01 0.01 0.01

cv (%) 3.30 7.03 2..79 7.24 4.n 11.m 7.31 't,81 6.18 14.07 6.01 1.53

ln a column, figures with same lette(s) or without letter(s) do not differ significantly whereas figures within

Age of seedlingsx

Date otlransnlanlinn

Planlheighl(cm)

No. ofeflctive

tillers hillt

No. ol non-

effectivetillers

hillt

No. oltotal

tillershillr

Panicle

length(cm)

No. olgrains

paniclel

No. ofsterile

spikeletsoaniclp:l

1000-grain

weight{ol

Grainyield

(t hrr)

Strawyield

(t ha'r)

Biologicalyield

(t har)Hr(%)

tt6.!Ec,

1 December 89.10 l-i 27.66 3.33 30.99 21.90 137.33 def 20.33 iik 21.23 6.16 6.86 13.02 47.31

15 December 91.03 d-h 34.00 3.33 37.33 21.70 137.33 def 23.33 ii 21.56 7.70 8.83 16.53 46.57

30 December 93.00 c-f 39.00 3.66 42.66 21.90 142.67 cd 22.66 ik 21.52 8.26 9.20 17.46 47.01

15 Januarv 93.20 c-l 39.33 3.66 42.99 23.03 149.66 bc 19.66 ik 21.27 8.50 9.60 18.10 46.96

30 Januarv 92.80 c-o 35.00 4.33 39.33 21.66 143.33 bcd 20.00 ik 21.23 7.96 910 17.06 46.65

15 Februarv 98.16 abc 24.66 3.66 28.32 22.96 1 10.66 o 45.00 el 21.07 6.s3 7.60 14.13 46.20

2 March 83.70 ik 13.33 4.00 17.33 23.13 89.33 h s2.66 d 21.72 1.90 2.16 4_06 46.6316 March 79.16 k - 9.66 3.66 13.32 21.76 66.66 i 63.33 b 21.22 1.66 1.96 3.62 45.87

€6qtItN

1 December 92.16 dh 30.33 4.33 34.66 22.93 140.00 def 20.00 ik 21.55 5.53 7.50 14.03 46.57

15 December 91.55 dh 37.33 3.33 40.66 u.16 141.33 def 21.33 iik 21.13 8.10 9.33 17.43 46.46

30 December 91.93 dh 40_66 3.33 4t.99 2..30 144.00 bcd 25.00 hi 21.69 8.43 9.53 17.96 46.93

15 January 101.56 a M.33 4.3it 48.66 24.40 163.33 a 18.00 k 21.58 8.90 10.33 19.23 46.36

30 January 100.66 ab 38.66 3.66 42.32 23.30 r50.33 b 19.33 ik 21.19 8.23 9.79 18.02 45.75

15 February 96.93 a-d 28.00 3.00 31.00 22.36 116.66 q 41.33 f 21.66 6.83 5.80 12.63 45.65

2 March 86.60 hii 13.00 3.66 16.33 n.73 92.66 h 48.00 e 21.09 2.06 2.53 4.56 u.9416 March 87.06 0-i 1 1.33 4.00 15.33 21.73 68.66 i 58.00 c 21.07 1.83 2.26 4.09 M.70

Eo6!t(O<f

1 December 90.83 e-h 24.33 4.00 28.33 22.40 134.sr I 21.33 iik 21.73 5.76 6.86 12.63 45.68'15 December 92.56 c-o 31.66 3.66 35.32 23.13 138.00 del 22.33 iik 2',t.14 6.33 7.53 13.86 45.38

30 December 93.73 c-f 35.33 3.66 38.99 22.66 134.66 el 29.33 0 21.04 7.60 8.70 6.30 46.43

I 5 Januarv 94.20c-l 37.33 4.00 41.33 n.73 142.33 cde 24.00 hii 21.66 8.00 9.06 7,06 45.02

30 Januarv 90.43 e-h 31.66 3.66 35.32 20.63 136.33 def 28.00 oh 21.32 7.26 8.53 5.79 45.9915 Februarv 89.76 foh 21.66 3.66 25.32 21.73 95.66 h 48.33 e 21.26 5.86 7.13 2.99 45.11

2 March 95.80 b-e 10.33 4.00 14.33 21.56 76.66 i 60.66 bc 21.12 2.06 2.50 4.56 45.20

16 March 83.63 iik 9.00 4.00 13.00 21.46 56.66 k 69.66 a 21.57 1.43 1.70 3.13 4s.uLevel ol

sionificance0.01 NS NS NS NS 0.01 0.05 NS NS NS NS NS

CV ("/") 3.30 7.03 n.79 7.24 4.77 '11.00 7.31 1.E1 6.18 14.07 6.01 1.53

26 TRANSPLANTTNG OF BORO RICE UNDER SRI METHOD

obtained in 12-day old seedlings transplanted on 1.?

January while the lowest grain yield

iffi'fti) uLrlnt"ined from the 45-day old seedlings transplanted on 16 March.

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