Abstract

Exploitation of the phenomenon of hybrid vigour for increasing crop yield on a commercial scale is the most important step in agriculture. Technical difficulties like smallnes of flowers, laborious emasculation, hand pollination, and bagging have proved to be time consum- ing and increased the cost of hybrid seed production. Several methods have been suggested to overcome these difficulties and the use of male sterility as a possible measure was emphasized by Jain (1959). But, cytoplasmic genetic male sterility is not yet available in cotton to exploit successfully the hybrid vigour. Hence, a method for inducing a high degree of male sterility with a selective gametocide chemical assumes special importance. In recent years, several attempts have been made to induce male sterility by treating the cotton plants with a gametocide F. W. 450 or Mendok (Sodium 2, 3 dichloro- isobutyric acid) of different strengths. In this paper, the results on the effect of F. W. 450 spray on Madras Cambodia Uganda. 1. cotton, are presented and the possibility of inducing male sterility in breeding programmes is discussed.

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