response of yield and yield components of corn to phosphate and zinc sulfate fertilizers application methods under water stress

to study the effects of phosphate and zinc sulfate fertilizers application methods on the yield and yield components of maize under water stress a randomized complete block with split plot factorial arrangement with three replications at research farm of the bu ali sina university was conducted in 2014. three levels of irrigation after 60, 90 and 120 mm evaporation from evaporation a pan was assigned in main plot and two factors including phosphate fertilizer application methods (broadcasting and placement) and zinc sulfate (non, foliar and soil application) were assigned in sub plots. the results showed that with increasing water stress from 60 to 90 mm evaporation of pan grain yield decreased by 28 percent, but in condition of severe water stress, (irrigation after 120 mm evaporation), grain yield decreased by 54 percent. in no stress conditions, foliar application of zinc sulfate, compared to soil application and no application increased significantly the number of grains row per ear, biological yield, corn length and its diameter. according to the results phosphate placement treatment in sever water stress and no zinc sulfate application conditions caused a significant increase in the number of grain per row and 100 grains weight. in this study the highest harvest index was obtained in no water stress plus zinc sulfate foliar application (47.56%).