Relative efficiency of32P uptake in a banana-based intercropping system

Abstract

Introduction. A study was conducted in India to assess the efficiency of 32 P uptake and the feasibility of intercropping using land-use efficiency parameters in a banana-based intercropping system. Materials and methods. Absorption of 32 P applied to plants in five-crop, two-crop and sole- crop systems involving banana Musa AAB ('Mysore'), ginger (Zingiber officinalis Rosc.), turmeric (Curcuma longa L.), cassava (Manihot esculenta Crantz.) and elephant yam (Amorphophallus cam- panulatus Blume.) was studied in field trials. The experiment was conducted for two years. During the first year, the main crop was planted during October, the main planting season for banana in India, and the intercrops were planted in early May of the next year. In the second year, both the main crop and intercrops were planted in May. Results. Radiophosphorus applied in the active root zone of one of the component species in the mixed crop system was found to be absorbed not only by the treated plant but also by the neighboring plants. Absorption by banana was prevalent. Differential effects of competition were manifested as observed by the relative uptake of 32 P. Lower relative uptake of 32 P was observed in the main crop banana when simultaneous planting of intercrops was done. Ginger and turmeric were not affected in relation to planting at different stages of the main crop, whereas cassava and elephant yam showed lesser relative 32 P uptake when planted later, confirming that dif- ferent crops in the mixed crop system react differently. Conclusions. The efficiency of different crops in terms of uptake varied with the system of planting. The higher relative efficiency of 32 P uptake in a multiple cropping system points to an improved efficiency of uptake and higher dry weight on a per plant basis. It confirms the efficiency and feasibility of the cropping system. Economic analysis emphasizes the concept and proves the viability of the system. India / Musa / Amorphophallus campanulatus / Manihot esculenta / Zingiber officinalis / Curcuma longa / phosphorus / radioisotopes / plant competition / intercropping / mixed cropping Efficacite relative de l'assimilation de 32 P en cultures intercalaires a base de bananiers.