The investigation of effect of planting date and foliar application Zinc sulfate and Selenium on tolerance to high temperature on two Wheat cultivars

In order to investigation the effect of planting date and foliar application Zinc sulfate and Selenium on tolerance to high temperature on two Wheat cultivars one experiment was carried out in a split factorial experiment based on a complete randomized block design with three replications at the experimental farm of Shahid Chamran University of Ahvaz during a growing season 2017-2018. Three factors were investigated in this experiment. initial factor including three planting date (Nov 11, Des 11, Jan 10). The solution type was used as the second factor: 1- foliar application with tap water (control), 2- foliar application with selenium (4 mg/lit), 3- foliar application with zinc sulfate (0.04%) and third factor including two wheat cultivars (Chamran and Star). According to the results in planting date of 20 January, the number of grains per spike decreased in the foliar application treatments by zinc solfate 10%, Selenium 36% and control 33% compared to similar treatments in the planting date of November 20th. In the planting date of January 20, the decrease in grain yield compared to the planting date of November 20th was 49.3% in the control treatment and 49.9% in the selenium treatment While in zinc sulfate treatment, yield reduction was 20.19%. According to the results obtained in folia application, Zn sulfate increased grain yield in two wheat cultivars by increasing the number of grains per spike, 1000- grain weight and grain filling duration.