Effects of anti-transpiration spraying and irrigation cutting off on yield and yield components of sunflower hybrid of Farrokh as second crop at Miyaneh region, Iran

To study the effects of anti-transpiration spraying and irrigation cutting off in different growth stages on yield and yield components of sunflower hybrid of Farrokhas second crop at Miyaneh region, an experiment was conducted at the Research Station of Faculty of Agriculture Islamic Azad University (Miyaneh Branch) during 2013 cropping season. The experiment was in randomized complete block design with three replications. The experiment factors were anti-transpiration spraying with paraffin, atrazine, and phenyl mercuric acetate (PMA), along with irrigation cutting off in inflorescence full blooming and seed filling stages. The traits of seed yield,, biological yield, harvest index, number of seeds per head, seed weight, oil percent, leaf dry weight, head diameter was measured at the end of experiment. There were significant difference of interaction between irrigation cutting off and anti- transpiration application on seed weight, head diameter at 1% and oil percentage at 5% probability level. PMA application caused the highest seed yield and head dry weight. Irrigation cutting off in inflorescence emergence stage along with atrazine implementation led to the highest oil percentage, head diameter and seed number per head. Regarding the results, anti-transpiration application and longer water storage could be one of the suitable methods for high production of sunflower in arid and semi-arid areas.