University of Agricultural Sciences, Bangalore, India
Online published on 25 January, 2012.
Data from field experiments indicated that application of GA at a concentration of 90–100 ppm on the 3rd day after flower bud initiation induced a high degree of male sterility without affecting female fertility in sunflower. The time of application appears to be critical for the extent of sterility. For practical purposes, sterility in sunflower can be induced by spraying plants with 100 ppm GA at the rate of 0.5–0.75 ml per plant on the 30th and 40th day after sowing. This technique can be followed with good results in the production of small quantities of hybrid seed and also in top crosses where the combining ability is to be tested in a large number of inbreds.
