Effect of Nitrogen and Phosphorus Fertilizer on Sunflower Seed Yield and Other Agronomic Characters

Abstract

The purpose of this experiment was to examine the effect of nitrogen and phosphorus mineral fertilizer on sunflower seed yield. l00-Kernel weight, percent oil content, and percent protein content. The levels of fertilization applied (Kg/ha) were: N_0 = 0, N_1 = 150, N_2 = 300, N_3 = 450, P_0 = 0, P_1 = 75, P_2 = 150, P_3 = 225. A factorial design with 5 blocks was used. Sunflower variety employed was Vniimk 8931. One half of N and all of P fertilizer were applied when plants were at four-leaf stage. The second half of N was applied when heading stage started.
Highly significant differences were found between different levels of N for seed yield. Effects of different doses of P and interaction effect of N X P were not significant for seed yield.
Significant differences were observed between N levels and between P levels for 100-Kernel weight. Interaction effect of N X P was not significant for this trait.
Main effects of N and P and their interaction were significant for both percent oil and percent protein content.
It was concluded that lower and moderate levels of N had considerably greater effect on seed yield, regardless of the applied amount of P fertilizer.
Kernel weight was increased at higher levels and moderate level of N and P fertilizer, respectively.
In general, percent oil content was negatively and percent protein content was positively related to the amount of N fertilizer applied. However, the maximum oil content and protein content were obtained at N_1P_0 and N_3P_2 respectively.