Effect of water stress and foliar application of iron and zinc on yield and yield components of sunflower for second cropping system

In order to study the effect of water stress and foliar application of iron and zinc on yield and yield components of sunflower for second cropping system, a field experiment in split plot design with three replications was conducted at the Agriculture Education Center of Birjand, in 2014 growing season. Water stress at two levels (control and grain filling stages) were assigned as main plots and four micronutrient treatments; Control, Fe, Zn, and Fe +Zn, were randomized in sub-plots. The results showed that plant height, head diameter, leaf number in the flowering and grain filling stages, head dry weight, leaf area index (LAI) in the flowering and grain filling stages, number of grain per head, 1000-grain weight, grain yield, biological yield and seed/husk were not affected by water stress, but reduced harvest index. Water stress at the grain filling stage reduced harvest index (18.29 %) compared to the control. Foliar application with micronutrient fertilizer (Fe and Zn) were not significantly different on all traits (With the exception of the number of leaves maturity). Foliar application with (Fe +Zn) increased number of leaves compared to the other treatments. Also, interaction between water stress and foliar application on traits were not significant. According to the results of this experiment, stopping irrigation at the grain filling stage and Foliar application with micronutrient fertilizer (Fe and Zn) were not significantly different for grain yield of sunflower for second cropping system in Birjand.