SEED YIELD AND YIELD CONTRIBUTING CHARACTERS AS INFLUENCED BY N SUPPLY IN RAPESEED-MUSTARD

Brassica juncea, cv. Pusa Bold, and B. campestris, cv. Pusa Kalyani, w ere raised under field conditions with varying levels of N supply from 0-120 kg ha(-1). The production profile of branches and pods thereon was measured per unit area basis, throughout the crop ontogeny. At mat urity, data on the yield contributing characters, viz. pod dry weight, pod number, seed number per pod, 1000 seed weight, seed wall ratio an d seed yield in different order branches, was recorded. The branching pattern and the number of pods produced on different order branches, i n the two species, was favourably modified by the increasing levels of N supply. Primary and secondary branches contributed to the seed yiel d to an extent of 80% of the total yield. Nitrogen treatment had no si gnificant effect on 1000 seed weight. B.juncea exhibited significantly higher yield over B. campestris. N supply up to 120 kg ha(-1) linearl y increased seed yield in both the species. However, it exerted a nega tive effect on partitioning of assimilates from pod wall to seed. The study indicated that rapeseed-mustard, grown under shea winter-season environment with adequate soil moisture, has the potential for higher N-fertilizer optima exceeding 120 kg ha(-1).