Effect of Antitranspirants on Yield of Grain Sorghum Under Limited Irrigation¹

Abstract

Abstract Most crops of grain sorghum are grown under conditions of limited irrigation or rainfall. Reduction of the degree and length of periods of moisture stress through the use of antitranspirants to control stomatal opening may increase the amount of time when photosynthesis takes place thus increasing crop yield with the water available. The purpose of this study was to determine the proper material, method, and timing of application for field use. Under limited irrigation conditions in the field, grain sorghum ( Sorghum bicolor (L.) Moench) was sprayed at various rates and times with phenylmercuric acetate (PMA), atrazine, and Folicote. Mean grain yield increases of 5 to 17% were obtained, indicating considerable economic possibility. Rates of application required were aproximately 60 g/ha for PMA, 130 g/ha for atrazine, and 2 liters/ha for Folicote. However, more work is needed on rates and volume of spray. Application just prior to the boot stage was more effective than a later application.