Evaluation of Upland Rice (Oryza sativa L.) Genotypes for Intercropping with Pigeon Pea (Cajanus cajan [L.] (Mill sp.))

Eleven upland rice genotypes of varying growth duration and plant stature were evaluated in two cropping systems: monocrop and intercrop, with pigeon pea cv. U pas 120, in order to study the effects of intercropping on rice grain yield and its contributing characteristics during 1990 to 1992 wet seasons. Cropping system and cropping system × genotype interaction effects were significant for yield ha^?1, panicle weight, panicles m^?2 and spikelet fertility suggesting the need for evaluating and selecting genotypes suitable for intercropping. Rice grain yield reduction in the intercrop ranged from 24.5 % in genotype RR 203-16 to 54.5 % in genotype Aditya. Panicle weight, total dry matter at flowering as well as at harvest, and harvest index were also reduced. Plant height and panicle weight were positively associated with yield in both systems, however, the yield was positively and significantly correlated with spikelets per panicle and spikelet fertility with the intercropping system. The correlation between cropping systems indicated the possibility of simultaneous improvement for these characteristics in monocropping and intercropping.