Response of Cotton Varieties to the Application of FW 450 for Inducing Male Sterility

Study conducted to determine the response of nine G. hirsutum varieties so the application of three doses of male gametocide, sodium 2, 3 dichloroisobutyrate (FW 450), for inducing male sterility revealed that with the increase in dose there was increase in male sterility. Moreover, with three applications of the chemical in some varieties a high as 89% of the flowers were sterile without any harmful effect on the functioning of the female organ. Effective chemieal dose was specific for a specific variety. Spraying of plants with the chemical result in higher frequency of sterile flowers in which pollen was fertile but anther did not dehisce as compared to the sterile flowers with empty anthers. But with the increase in concentration of the chemical there was increase in the frequency of sterile flowers of later type and a corresponding decrease in the frequency of former type of sterile flowers.