Effect of nitrogen application on partitioning of biomass, seed yield and harvest index in contrasting genotypes of oilseed brassicas ,

Abstract

Five genotypes of Indian mustard [Brassica juncea (L.) Czernj. Cosson], viz. RH 30 , RH 8814 , GJM 9056 , CS 52 and Kranti , and 1 genotype of Swede rape (Brassica napus L.) cv. GSH 1 were grown to assess the effect of various nitrogen levels (0,40,60 and 80 kg Nlha) on dry matter partitioning, seed yield and harvest index during the winter seasons of 1993 94 and 1994 95. Stem and leaf constituted the major part of plant biomass upto peak flowering (66 days after sowing), onwards and siliquae continued to increase their share to plant . biomass irrespective of nitrogen levels and genotypes. Total dry matter increased significantly up to 60 kglha. For above ground plant biomass, RH 8814 was significantly superior at 66, and 108 days after sowing and at harvest than RH 30 , GJM 9056 , CS 52 , GSH 1 and Kranti. Seed yield increased significantly up to 80 kglha. There were non significant differences in seed yield among Brassica juncea genotypes and all these were significantly superior to Brassica napus GSH 1 . Harvest index increased with the increasing nitrogen levels and RH 30 genotype had the better harvest index than other genotypes.