Abstract

A field experiment was conducted at Main Research Station, University of Agricultural Sciences, Dharwad, India during kharif 1999 under rainfed conditions on medium black clay soils, to study the impact of nitrogen and phosphorus levels and ratios on seed filling and seed yield of sunflower hybrid. Experiment was laid out in randomized block design with nine treatments comprising of varied N/P ratios (0.67 to 2.00) alongwith control. The results revealed that total number of seed rows and seeds head were unaffected due to treatments except control. However, higher per cent of filled rows (84.5) and lower per cent of unfilled seed rows (15.5) were noticed in the treatment receiving N/P ratio of 1.00 with 2.00:2.00 fertilizer level. Similarly, more per cent of filled seeds (92.8) and less per cent of unfilled seeds (7.2) were also noticed in the same treatment. Thus, due to the higher per cent of filled seed rows and per cent of filled seeds, the treatment consisting of N/P ratio of 1.00 with 2.00:2.00 (120 kg N and 120 kg P,0, ha¹) fertilizer level produced higher seed yield (3554 kg ha) as compared all other fertilizer levels and control. Correlation coefficient between per cent of filled rows, per cent of filled seeds and seed yields were also positive and significant.

Keywords: Sunflower, Seed filling, Nitrogen, Phosphorus, Yield.