Effects of stages and amount of nitrogen foliar application on yield and yield components in hybrid alestar sunflower

摘要

The object of this study was to investigate effects of stages and amount of nitrogen foliar application on yield and yield components in hybrid Alestar sunflower. Sunflower is one of the most important oil-grain in Iran because of high quality of its oil. The experimental design was a factorial in randomized complete blocks with three replications. The factors were concentrations of urea foliar application with 3 levels (a0: control, a1: 3% urea concentration and a2: 5% urea concentration and foliar application stages with 2 levels (b1: 8-10 leaf stage and b2: flowering stage). Number of seeds in head and grain yield were measured after harvest. Research results showed that there was a significant difference in interaction between concentration and foliar application stages of nitrogen on number of seeds in head. Foliar application of urea with 5% concentration in 8-10 leaf stage had increased number of seeds per head compare to control group and other treatments about % 45 and % 28.27 respectively. Foliar application of nitrogen with 5% urea concentration was significantly increased grain yield compare to control treatment and urea concentration of 3% about % 30.27 and % 7.50 respectively.