Plant Physiology Division, Indian Agricultural Research Institute, New Delhi-110012
25 varieties of soyabean were evaluated for their growth and yield characters. It was observed that the yield was determined differentelly among the varieties. In one group the yield was determined largely by dry matter production and photosynthetic area. In other group the partitioning of dry matter was largely responsible for the yield determination and in the third group dry matter production as well as partitioning, both were equally important. It was also established that besides the positive correlation of net assimilation rate and specific leaf weight with seed yield, fruit number and harvest index, the major differences in seed yield were also attributable to the duration of development period (days from flowering to yield formation).
