Performance of sunflower varieties under graded doses of nitrogen in redloam soils of Kerala

Abstract

An experiment using three varieties of sunflower and three levels of nitrogen was conducted at the College of Agriculture, Vellayani during 1974 in order to assess the performance of sunflower varieties under different levels of nitrogen. The varieties tried were EC.68413, EC. 6841 4 and Sunrise selection. The levels of nitrogen were 40 kg, 90 kg and 120 kg per hectare. The results indicated that there was no significant difference among the varieties in plant height, total dry matter production, leaf area index net assimilation rate, lodging, head diameter, number of seeds per head, percentage of filled grains per head, 1000 seed weight and yield of seeds. But, there was significant difference in the yield of atover and oil and protein contents of seeds among them. The effects of incremental doses of nitrogen were significant in head diameter and yield of seeds. Maximum yield of 1887.1 kg seeds per hectare was obtained at 80 kg nitrogen per hectare.