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Scientia Horticulturae 139 (2012) 71–78

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Responses of ‘Sunrise-solo’ pawpaw, okra and cucumber components of pawpawbased cropping system to time of intercropping

O.O. Olubode ∗, I.O.O. Aiyelaagbe, J.G. BodundeDepartment of Horticulture, University of Agriculture, P.M.B. 2240, Abeokuta, Ogun State, Nigeria

a r t i c l e i n f o

Article history:Received 28 February 2012Accepted 1 March 2012

Keywords:Abelmoschus esculentus L. MoenchCarica papaya L.Cucumis sativus L.Economic returnsTime of intercroppingPawpaw-vegetable mixtureLand equivalent ratioGrowth and yield responses

a b s t r a c t

Between 2006 and 2007, field experiments were conducted at Abeokuta, Southwestern Nigeria to deter-mine the response of ‘Sunrise solo’ pawpaw (Carica papaya L.) intercropping with okra (Abelmoschusesculentus L. Moench) var ‘V35’ and cucumber (Cucumis sativa L.) var ‘Market-more’ 3 weeks beforetransplanting (early), same-time (simultaneous) and 3 weeks after transplanting of pawpaw (late intro-duction). The experiment was a split plot design laid out in a randomized complete block design with threereplicates. Vegetative and reproductive growth of pawpaw and intercrops were significantly retarded(p ≤ 0.05) compared to monocrop in all components of the system. Planting vegetables before pawpawor planting both simultaneously significantly enhanced flowering of pawpaw (p ≤ 0.05) compared withintercropping pawpaw with vegetables 3 weeks after transplanting. Nonetheless, fruit yield of pawpawwas highest (p ≤ 0.05) in late intercropping (42.7 t/ha) compared to simultaneous and early intercrop-pings (41.7 and 40.5 t/ha, respectively). Despite the yield reduction recorded under crop mixtures, higherland equivalent ratio (LER) of 1.61 and 1.94 was recorded for pawpaw in okra and cucumber mixtures,respectively and LER of 1.97, 1.67 and 1.68 for early, simultaneous and late introduction, respectively.The economic returns calculated indicated a profit margin of 67, 74 and 78% under one, two or threecropping times with cucumber compared to under sole pawpaw (64%), sole cucumber (56%) or sole okra(45%).

© 2012 Elsevier B.V. All rights reserved.

1. Introduction

The beneficial effects of intercropping systems compared tosole cropping with regard to increased productivity, weed controland diversification of outputs have been reported by many work-ers (Altieri, 1987; Aiyelaagbe and Jolaoso, 1992; Olasantan, 2001;Zhang and Li, 2003; Ofosu-Anim and Limbani, 2007). Although,cucumber and melon intercrops especially provide higher soilmoisture content and cooler soil temperatures resulting in moreconducive environment for improved growth and yield of thecomponent crops (Ikeorgu, 1984; Ossom, 2003), physiologicallyrelated growth depression often observed in sole Homestead paw-paw (Aiyelaagbe et al., 1986; Olubode and Fawusi, 1998) at thephysiological pawpaw transformation from vegetative growth toflowering/fruiting calls for an investigation on the most appropriatetime to introduce intercrops in pawpaw crop mixtures, possibil-ity raised a need to determine a safe period to introduce or notto introduce annual intercrops in pawpaw and thus necessitatesmore research into vegetable intercrops that could be compati-ble with pawpaw when grown as a major crop. The objective of

∗ Corresponding author. Tel.: +234 8038572707; fax: +234 39243045.E-mail address: [email protected] (O.O. Olubode).

this study therefore was to determine the best time to introduce avegetable intercrop into a pawpaw orchard to enhance its produc-tivity.

2. Materials and methods

The experiment was conducted between 2006 and 2007, at theUniversity of Agriculture, Abeokuta, Ogun State, Nigeria (latitude7◦12′N, longitude 3◦20′E at 100 m above sea level). The soil ofthe experimental plot was fine loamy at the 0–15 and sandy at16–30 cm depth (Table 3). The moisture availability of the experi-mental location increased from 1153.4 mm in 2006 to 1201.6 mm in2007. However, despite the triple peak in April, June and Septemberof 2006 and the highest peak recorded in July of 2007, the meanscalculated for the location revealed a double peak rainfall pattern inJune and September with a depression in August which is charac-teristic of the area. Sunrise solo pawpaw was intercropped withokra and cucumber planted 3 weeks before transplanting paw-paw (early), or at same time as pawpaw seedling or transplanted(simultaneous) or 3 weeks after pawpaw was transplanted (late).The experiment was a split plot laid out in a randomized completeblock design with three replications. Main plot was crop mixtureand sub-plot was the time of introduction. A mono-crop of paw-paw was planted separately as control. The sole treatment was

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72 O.O. Olubode et al. / Scientia Horticulturae 139 (2012) 71–78

Table 1Parameters periods of measurement in component crops of pawpaw intercropped with okra or cucumber.

Crop component Parameter measured Interval

Pawpaw Plant height (cm), stem girth (cm), number of leaves, leaf area (cm2), canopy spread (cm). FortnightlyNumber of flowers, number of fruits and fruit yield (t/ha). Every week

Okra Plant height (cm), number of leaves, number of branches, leaf area (cm2) (Asif, 1977). Every weekNumber of pods, pod yield (t/ha). Every week

Cucumber Vine length (cm), number of leaves, number of side vines, leaf area (cm2). Every weekNumber of flowers, number of fruits and fruit yield (t/ha). Every week

compared with intercropped pawpaw in a randomized completeblock design replicated three times.

The two vegetables intercropped into pawpaw were okra (Abel-moschus esculentus L. Moench) var. ‘V35′, an erect, day neutral andearly yielding okra variety and cucumber (Cucumis sativus L.) var.‘Market-more’, a creeping and downey mildew tolerant variety.The pawpaw (Carica papaya L.) variety planted was ‘Sunrise solo’, ahermaphrodite variety with pyriform red fleshed fruits, weighing300–350 g. The choice of intercrops as based on their importance inlocal diets and their contrasting growth habits. The main plot wasmeasured at 8 m × 6 m and was separated by 4 m-walk border. Paw-paw, okra and cucumber were spaced 2 m × 2 m, 0.50 m × 0.30 mand 1.5 m × 1 m, respectively. The intercrops were planted in thealleys of pawpaw leaving 50 cm from pawpaw seedlings. The plantswere fertilized with Pace setter organo-mineral fertilizer (OMF)was applied at the rate of 10 t/ha.

The leaf area (cm2) of pawpaw, okra and cucumber weredetermined non-destructively using regression equations Y = 47.09X − 316.06 for pawpaw (Aiyelaagbe and Fawusi, 1984), Y = 115X − 1050 for okra (Asif, 1977) and Y = 12.9 X − 54.31 for cucumber(Aiyelaagbe and Adedokun, unpublished data). In these equations,‘Y’ is the leaf area (cm2) and ‘X’ is the sum of the media midrib(cm/plant). The fruit yield was determined by extrapolation ofharvestable yields from female and hermaphrodite trees at 1850per hectare assuming a 1:2:1 male to female to hermaphroditeratio in the field. Monetary value was calculated at the cur-rent price while profit margin was obtained as the differencebetween production cost and revenue. The experiment was man-aged as an organic plot. The harvesting of the okra and cucumberintercrops commenced at 6 weeks after sowing (WAS), whilethe pawpaw fruits were harvested at the colour breaking stage.The experiment was strictly rain-fed. However, supplementarywatering was done to offset soil moisture stress during the dryweather.

2.1. (a) Pawpaw okra cucumber trial – experiment I

In 2006, two-month-old pawpaw seedlings were transplantedinto already dug 60 cm3 sized holes. The juvenile pawpaw inter-cropped with okra and cucumber using the early, simultaneous andlate sequences as described earlier. The early vegetable introduc-tion three weeks before transplanting of pawpaw (19th June 2006),the simultaneous vegetable introduced at same time with pawpaw(10th July 2006), and the late vegetable introduced at three weeksafter pawpaw establishment (31st July 2006).

2.2. (b) Pawpaw okra cucumber trial – experiment II

In 2007, seeds of okra and cucumber were sown into the alleysof mature pawpaw at the onset of rains, 3 weeks before, sametime and 3 weeks after flowering respectively. The early vegetableintroduced at three weeks before flowering (15th April 2007), thesimultaneous vegetable introduced at same time with flowering(2nd May, 2007), and the late vegetable introduced at three weeksafter pawpaw flowering commenced (28th May, 2007).

The productivity efficiency was evaluated by comparing the pro-ductivity of a given area of intercrop with that of the sole crops usingthe individual crop relative yield total (RYT) and land equivalentratio (LER) (Wiley, 1979a,b). The profit margins were calculatedin percentage of the profit based on the totality of farm resourceinputs (labour, energy, organo-mineral fertilizer costs) in the yearto determine the profitability of the cropping system.

Data collections by measurement of plant vegetative and repro-ductive growth parameters was made on the component cropswhich are described in Table 1. These were subjected to the anal-ysis of variance procedures (SAS, 1990). Treatment means for eachparameter measured were compared using the least significantdifference (Figs. 1–3) and standard error technique (Tables 2–4)(Gomez and Gomez, 1984).

3. Results and discussion

3.1. Vegetative growth response of component crops

Intercropping juvenile pawpaw with okra or cucumber signif-icantly decreased (p ≤ 0.05) plant height and canopy diameter ofpawpaw, but it did not significantly influence Leaf Area Index(LAI). The effects of intercropping with okra or cucumber did notdiffer significantly from one another (Fig. 1A–C). The sequenceof intercropping with vegetables (before, simultaneously or aftertransplanting pawpaw) did not have consistent effects on the veg-etative growth of juvenile pawpaw (Fig. 1D–F).

With the exception of the initial higher plant height and higherleaf area of early introduced okra in juvenile pawpaw, sole okrawas higher (p ≤ 0.05) in leaf area (Table 5), but sole okra was notdifferent from early or simultaneous okra introductions while bothwere better than late okra. The sole cucumber was significantlybetter (p ≤ 0.05) in main vine length and leaf area in juvenile paw-paw (Table 5), but was not different from cucumber early in mainvine length. The lower responses were recorded by cucumber early,simultaneous and late introductions in leaf area.

Though there are several factors that contribute to inter-annualvariations of LAI (Martens et al., 1993), the LAI as an indicatorof stress can be used to compare canopy development over time(Marschner, 1986; Correia et al., 2004). In pawpaw, the higherresponses of sole pawpaw in plant height and canopy spread indi-cated that crop mixtures retarded juvenile pawpaw growth but thereduced LAI of the intercrops indicated significant stress impositionby the pawpaw. The trend of pawpaw plant depression observed inokra mixtures indicated nutritional stress at the juvenile pawpawstage but a physiological stress at mature pawpaw.

Palaniappan (1985) and Olasantan and Lucas (1992) have bothseparately described taller and shorter component crops responsesto light interception in mixtures. The effects of intercroppingmature pawpaw with cucumber on plant height did not differsignificantly from those of sole pawpaw. However, intercroppingmature pawpaw with okra significantly decreased (p ≤ 0.05) itsplant height compared with sole pawpaw or intercropping withcucumber which indicated that either cucumber in pawpaw hadan ameliorative effect on the microclimate which confirms Ikeorgu


O.O. Olubode et al. / Scientia Horticulturae 139 (2012) 71–78 73

Table 2The weather data showing rainfall (cm) pattern recorded for the experimental location during the 2006 to 2007 period.

Year/rainfall (mm) Month

J F M A M J J A S O N D

2006 4.5 62.0 62.1 180.3 77.0 262.0 92.8 61.8 250.7 56.8 43.4 0.02007 0.5 0.0 15.5 17.3 120.2 213.9 369.8 140.5 192.0 119.2 11.4 1.3

Source: Agromet Dept., University of Agriculture, Abeokuta, Location 7◦12′N, 3◦20′E.

Table 3The pre-cropping soil physico-chemical properties of the experimental sites.

Depth (cm) Particle size analysis Chemical analysis Exchangeable bases

% sand % clay % silt Textural class pH (H2O)a OrgMatter(%)b

% N P ppmc Kcmol kg−1c

Nacmol kg−1d

Cacmol kg−1d

Mgcmol kg−1d

0–15 61.20 22.00 16.80 Fine loamy 7.78 1.86 0.081 6.74 0.31 0.35 3.48 0.5216–30 73.40 14.30 7.30 Sandy 6.90 0.76 0.055 10.05 0.15 0.43 1.66 0.18

a 1.5 soil: water ratio.b Walkey and Black (1934).c 1: 100 mnol NaOHCo3/L, 16 h shaky time, (Colwell procedure).d DPTA extraction Heanes (1981).

Table 4Profit margins calculated for the sole and at different times of intercropping in pawpaw/vegetable mixtures.

Crop mixture Fruit yield (t/ha) Yield value (N × ‘000,000)a Crop Mixture Profit

(N × ‘000,000)a

Crop Mixture

Production cost (N

× ‘000,000)a

Profit margin (%)

Py Cu Sole Mixed Mixed Mixed Mixed

Intercropping times Intercropping times Intercropping times Intercropping times

1 2 3 1 2 3 1 2 3 1 2 3

Sole cropsSunrise 55.0 – 2.6 – – – 1.7 – – 0.9 – – 64.4 – –Okra – 9.3 1.2 – – – 0.5 – – 0.6 – – 45.0 – –Cucumber – 17.4 1.7 – – – 1.0 – – 0.8 – – 56/0 – –

Crop mixturesOkra early 43.3 4.4 2.0 2.6 3.1 3.7 1.6 2.2 2.7 0.9 1.0 1.0 63.7 68.7 72.8Okra simultaneous 45.5 4.1 2.1 2.6 3.2 3.7 1.7 2.2 2.7 0.9 1.0 1.0 64.5 68.9 72.7Okra late 40.8 4.0 1.9 2.4 2.9 3.4 1.5 1.9 2.4 0.9 1.0 1.0 61.1 66.3 70.6Cucumber early 37.7 12.0 1.8 3.0 4.1 5.3 2.0 3.1 4.3 1.0 1.0 1.1 68.0 75.3 80.1Cucumber simultaneous 37.9 9.4 1.8 2.7 3.6 4.6 1.8 2.6 3.5 1.0 1.0 1.1 64.9 71.9 76.8Cucumber late 44.6 9.3 2.1 3.0 3.9 4.9 2.1 2.9 3.8 1.0 1.0 1.1 68.5 74.0 78.2

Main valuesSunrise okra 43.2 4.2 2.0 2.5 3.1 3.6 1.6 2.1 2.6 0.9 1.0 1.0 63.1 68.0 72.0Sunrise cucumber 40.1 10.2 1.9 2.9 3.9 4.9 1.9 2.9 3.9 1.0 1.0 1.1 67.1 73.7 78.4Early 40.5 8.2 1.9 2.8 3.6 4.5 1.8 2.6 3.5 0.9 1.0 1.0 65.8 72.0 76.5Simultaneous 41.7 6.8 1.9 2.7 3.4 4.1 1.7 2.4 3.1 0.9 1.0 1.0 64.7 70.4 74.8Late 42.7 6.7 2.0 2.7 3.4 4.1 1.8 2.4 3.1 0.9 1.0 1.0 64.8 70.2 74.4

a N 150 equivalent to $1 US dollar, selling price/kg-pawpaw =N 46.50, okra =N 125 and cucumber =N 100.

Table 5Vegetative growth responses of okra and cucumber vegetables intercropped in juvenile and mature pawpaw.

Crop mixture/sequence Vegetable intercrops

Okra Cucumber

Plant height (cm) Leaf area (cm2) Main vine length (cm) Leaf area (cm2)

2006 2007 2006 2007 2006 2007 2006 2007

5a 9a 5a 9a 5a 9a 5a 9a 5a 9a 5a 9a 5† 9† 5† 9†Sole vegetable 11.2 38.7 13.4 41.7 1730 2560 1340 2440 100.8 172.7 97.3 188.1 2416 4583 1824 3952Early introduction 14.5 44.5 10.4 31.3 2013 2707 1020 2110 61.0 181.4 15.0 21.5 1776 3280 790 1736Simultaneous introduction 8.5 41.4 8.6 29.0 1363 2510 1063 1957 78.9 162.5 23.0 32.8 1651 3610 725 1591Late introduction 9.9 39.9 9.0 28.0 1317 2233 910 1740 62.9 158.7 16.0 23.2 1476 3410 571 1257SE ± 0.05 1.31 4.09 0.71 2.59 128 204 96 167 3.26 7.57 1.39 2.06 219 501 76 161

TDW: total dry weight.a Weeks after planting.



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Fig. 1. Vegetative growth responses of juvenile pawpaw to time of intercropping with okra and cucumber showing: (A and B) plant height (cm), (C and D) canopy spread(cm) and (E and F) leaf area index. Symbols (♦): sole or early, (�): pawpaw/okra or simultaneous and (�): pawpaw/cucumber or late. Vertical bars represent LSD (p ≤ 0.05).

(1984) findings or cucumber had no significant competitive effectwhen cultivated in mixture with pawpaw. Nonetheless the effectsof intercropping with cucumber or okra on canopy diameter or LAIof pawpaw generally did not differ significantly from one anotheror sole pawpaw (Fig. 2A–C).

The response of various growth parameters of mature pawpawto sequence of intercropping differed. Intercropping pawpaw withvegetables before the onset of flowering in pawpaw (early) pro-duced the tallest pawpaw plants. Intercropping pawpaw at theonset of flowering (simultaneous) produced plants that were signif-icantly shorter (p ≤ 0.05) than pawpaw intercropped early but theywere significantly taller (p ≤ 0.05) than pawpaw intercropped withvegetables 3 weeks after flowering commenced (late, Fig. 2A–C).The effects of early or simultaneous intercropping on canopydiameter of mature pawpaw did not differ significantly from oneanother but both had larger canopies than pawpaw plants inter-cropped after flowering commenced (late). LAI of mature pawpaw

intercropped simultaneously or late did not differ significantly, butthey had significantly smaller canopies than pawpaw plants inter-cropped before flowering commenced (Fig. 2D–F).

The sole okra in mature pawpaw was higher in growth param-eters compared to crop mixtures with pawpaw (Table 5). The earlyand simultaneous introduced okra were better than late in plantheight and leaf area and times of introduction were not differentin plant height and leaf area (Table 6). Sole cucumber had signifi-cantly higher responses in main vine length and leaf area comparedto crop mixtures with pawpaw at mature pawpaw stage (Table 5).The early and simultaneous introduced cucumber was better thanlate in plant height and leaf area.

The pawpaw in early introduced vegetable through the heightadvantage and probably through different niche explored in soilenvironment probably responded to nutrient zones of depletioncrated by the intercrop by exploring resources better than the veg-etable components (Goldberg et al., 1983; Vandermeer, 1990; Fukai



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Fig. 2. Vegetative growth responses of mature pawpaw to time of intercropping with okra and cucumber showing: (A and B) plant height (cm), (C and D) canopy spread (cm)and (E and F) leaf area index. The symbols (♦): sole or early, (�): pawpaw/okra or simultaneous and (�): pawpaw/cucumber or late. Vertical bars represent LSD (p ≤ 0.05).

and Trenbath, 1993). The response of the highly stressed paw-paw with early vegetable introduction was better in comparisonto simultaneous introduction which had moderate level of compe-tition. The supposedly less stressed pawpaw with late introductionof vegetables had further growth depression. This indicated that

pawpaw with late introduction could have responded to addi-tional stress of competing with intercrops for nutrients at theenergy demanding physiological stage of pawpaw transformationfrom vegetative to reproductive activities (Aiyelaagbe et al., 1986;Olubode and Fawusi, 1998).

Table 6Reproductive growth responses of okra and cucumber vegetables intercropped in juvenile and mature pawpaw.

Crop mixture/sequence Vegetable intercrops

Okra Cucumber

Number of fruits Fruit yield (t/ha) Number of fruits Fruit yield (t/ha)

2006 2007 2006 2007 2006 2007 2006 2007

11a 11a 11a 11a 11a 11a 11a 11a

Sole vegetable 12 12 5.3 4.0 7 8 9.6 7.8Early introduction 5 1 3.9 0.6 4 2 9.7 2.3Simultaneous introduction 5 1 3.6 0.5 4 1 8.2 1.1Late introduction 5 1 3.5 0.5 4 1 8.1 1.2SE ± 0.05 0.15 0.06 0.08 0.04 0.33 0.22 0.84 0.20

TDW: total dry weight.a Weeks after planting.



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Fig. 3. Reproductive growth responses of mature pawpaw to time of intercropping with okra and cucumber showing: (A and B) fruit setting rate (%), (C and D), number offlowers/plant and (E and F) fruit yield (t/ha). The symbols (♦): sole or early, (�): pawpaw/okra or simultaneous and (�): pawpaw/cucumber or late. Vertical bars representLSD (p ≤ 0.05).

3.2. Reproductive growth response of component crops

According to Griffith and Banowetz (1995), observations in sev-eral crops, especially fruit trees, have indicated that the amountof vegetative growth was inversely related to flowering whilealso fruit setting rate had a direct relationship with the num-ber of fruits set per plant and marketable fruit yield (Bodunde,1999). The effects of intercropping pawpaw with okra on flowerproduction of pawpaw did not differ significantly from those ofsole pawpaw. However, between 60 and 72 WAT, intercroppingpawpaw with cucumber significantly enhanced flower produc-tion in pawpaw compared with those grown sole or intercroppedwith okra which like in the vegetative growth also confirmedIkeorgu (1984) findings (Fig. 3A). Between 64 and 88 WAT, inter-cropping with okra or cucumber significantly decreased fruitset compared with sole pawpaw. The effects of intercroppingwith okra were more severe than those of cucumber (Fig. 3B).Nonetheless, intercropping with okra or cucumber significantlydecreased fruit yield of pawpaw compared with sole pawpaw

which confirmed findings of Aiyelaagbe and Jolaoso (1992) andOlubode et al. (2008) that intercropping generally retards paw-paw growth and yield. However, the effects of intercropping withokra or cucumber did not differ significantly from one another(Fig. 3C).

Between 48 and 56 WAT, the effects of early intercroppingof pawpaw on flower production of pawpaw were the sameto those of simultaneous intercropping. Both set of plants pro-duced significantly more flowers than pawpaw plants intercroppedlate. However, between 64 and 72 WAT, pawpaw intercroppedlate produced significantly more flowers than those intercroppedsimultaneously or grown sole (Fig. 3D). Between 52 and 60 WAT,fruit set of pawpaw plants intercropped late or early did not differsignificantly but both had higher fruit set than pawpaw inter-cropped simultaneously with okra or cucumber (Fig. 3E). However,at 64 and 76 WAT, fruit set of pawpaw plants intercropped late wassignificantly higher than those of pawpaw intercropped with veg-etables early or simultaneously (Fig. 3E). Between 64 and 80 WAT,early intercropping of pawpaw enhanced fruit yield compared with



simultaneous or late intercropping. Pawpaw plants intercroppedlate produced the least fruit yield (Fig. 3F). Intercropping simul-taneously or late had competitive effect on component crops incropping systems as earlier reported by Magdy et al. (2007) thatsimultaneous planting of cucumber in okra depressed both cucum-ber and okra yield to 71% and 83.2% respectively compared to solecropping, and by Ajayi et al. (2009) that significantly less tillersand higher grain yield of rice were obtained when melon wasintroduced simultaneously or 2 weeks after sowing rice than whenmelon was introduced 4 weeks after sowing rice.

The sole okra in juvenile pawpaw was higher in number of fruitsand fruit yield while the simultaneous and late okra were lowerin fruit yield compared to early introduction (Table 6). The solecucumber was also significantly better in number of fruits, whilecucumber early, simultaneous and late introductions were lowerin number of fruits in juvenile pawpaw. The sole okra in maturepawpaw was higher in yield parameters compared to crop mixtureswith pawpaw. The times of introduction were not different in num-ber of fruits, though early okra was lower compared to sole okrabut was better than both simultaneous and late introduced okra infruit yield (Table 6). Like was observed in the vegetative growth,the sole cucumber had significantly higher responses in num-ber of fruits and fruit yield compared to crop mixtures (Table 6).These significantly higher responses of sole okra or cucumber ingrowth and yield parameters were indicative of a serious andsignificant depression under crop mixtures with pawpaw whichcould be in response to pawpaw taller height and matured size.These reduced crop performances in growth and yield corrobo-rated previous reports (Olaniyan et al., 2006; Magdy et al., 2007)that intercropping generally depressed cucumber and okra growthand yield. However, at the mature pawpaw stage, the severity ofgrowth and yield reduction in intercropped cucumber as well asin okra could probably be related to significant changes in LAI ofpawpaw.

3.3. Productivity and profitability of the mixtures

Hauggaard-Nielsen et al. (2003) had reported that the calcu-lated LER proved that plant growth resources were used from 27to 31% more efficiently by intercrop than the sole crop. There wassignificant difference in the productivity indices observed for theintercrop and the sequence effect where pawpaw/cucumber washigher than pawpaw/okra and both better than sole (Fig. 4A andB). Both early and simultaneous okra were not better than lateokra while early cucumber was better than both late and simul-taneous which were not different (Fig. 4B) but the LER had index of>1.0. By the intercrop relative yield total values compared to paw-paw it was obvious that cucumber contributed more to the LERwhich confirmed findings of Aiyelaagbe and Jolaoso (1992), whilethe pawpaw on the other hand by the higher yield biomass con-tributed more to the percent profit margins. The sole crops recorded

highest net returns for sole pawpaw at 64.42% (N 1,648,141),

followed by sole cucumber at 55.96%, (N 975,900), while sole

okra at 45.01% (N 523,250) was least. The net returns calculatedfor the mixtures under introduction time showed a profit mar-

gin which was highest for pawpaw/cucumber late atN 2,057,181,

followed by pawpaw/cucumber early atN 1,999,331, while paw-

paw/okra late was least atN 1,466,271. At one time, intercroppingrecorded higher yield value of the mixture (Table 4), despite thelower fruit yield recorded under pawpaw in mixtures, the cucum-ber component’s higher yield/hectare response and higher yieldvalue subsequently resulted in higher percent profit margins under

Fig. 4. Productivity responses of pawpaw to: (A) crop mixtures with okra andcucumber, and (B) time of intercropping at early, simultaneous and late vegetableintroduction RYT; total relative yield, LER; land equivalent ratio. Vertical bars rep-resent SE ± (p ≤ 0.05).

pawpaw/cucumber in the early, simultaneous and late introduc-tion with 67.84, 64.88 and 68.46%, respectively compared to lower63.71, 64.54 and 61.12%, respectively under the okra mixtures.

By extrapolating with an assumption of a two timed croppingcycles of the intercrops in pawpaw, the pawpaw/cucumber wasmuch higher in the early, simultaneous and late introduction com-pared to lower but highly improved responses under the okramixture (Table 4). With a further three timed cropping cycles ofintercrops produced much higher percent profit margins of paw-paw/cucumber at the early, simultaneous and late introductioncompared to the lower but much improved under the okra mix-tures.

The profit obtained at the one time cropping cycle of intercropin pawpaw was marginally not different from the profit obtain-able in sole cropping. Thus depending on the prevailing marketforces, vagaries of weather and many other factors that cannot becontrolled by pawpaw growers, a productive cropping system maynot necessarily be profitable implying that better cultural practiceswould need to be adopted for higher profitability. According toZandstra (1979) cited by Balasubramanian and Sekayange (1990)utilizing different mechanisms in cultural manipulations couldassist to maximize profit in intercropping systems. In this paw-paw trial, maximum utilization of resources would require utilizingthe double peaked rainfall pattern with at least a two time inter-cropping of the short duration annual crops, while a third plantingwhich is only possible under irrigation will further optimize thefarmers income.



In conclusion, since intercropping is practiced with the aim ofmaximizing plant co-operation rather than competition for maxi-mum crop yields (Sullivan, 2001), identifying the most appropriatetime for intercropping could have a tremendous benefit for paw-paw growers. In the judicious use of time management, thereforeand for better land utilization and crop productivity of pawpawmixture with cucumber, an early and/or late intercropping in paw-paw could be better a cropping system to be adopted by pawpawgrowers. However, while discouraging the intercropping at maturepawpaw stage, the planting of intercrops at the juvenile pawpawstage and at several times as possible of the intercrop in the bid toacquire an early earning from short duration intercrops before paw-paw come into full establishment and fruit bearing would furtherassist to maximize the farmer’s income.

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