Component interactions and nutrient dynamics in pawpaw / cucumber mixtures in a pawpaw based cropping system

Abstract

Field experiments were conducted to determine the crop interaction and nutrient dynamic responses of paw paw (Carica papaya L.), var. 'sunrise solo' and 'homestead selection' when intercropped with cucumber (Cucumis sativa L.) var. 'Market-more' at 3-weeks before (early), same-time (simultaneous) and 3-weeks after paw paw (late introduction). The experiment was a split plot design replicated three times. The result showed that leaf area index (LAI) as a stress indicator; by the significant and non-significant difference at juvenile and mature paw paw stages respectively indicated the level ofstress imposed on paw paw in the crop mixtures and at different times of intercropping. The juvenile homestead recorded significantly higher responses in plant height, petiole length, canopy spread and LAI compared to sunrise. The lower growth responses of paw paw cultivated sole compared to paw paw in mixture indicated an ameliorative effect played by cucumber, however late introduction of cucumber in  to paw paw which occurred at the critical growth periods of both component crops caused significant growth retardation on paw paw and cucumber. The sunrise paw paw also recorded significantly more number of fruits and was higher in fruit yield compared to homestead. The sunrise in mixture was better in relative yield total (RYT) recorded for vegetable RYT but homestead was better in paw paw RYT The lower profit margins obtained at one intercropping cycle in pawpaw compared to sole cropping was improved at two intercropping cycles due to higher yield value of early introduced cucumber.