GAMETOCIDAL POTENCY OF ETHYL 4' FLUOROOXANILATE IN RICE

Abstract

Relative efficacy of three oxanilate formulations namely ethyl 4'fluorooxanilate, ethyl 4'bromooxanilate and ethyl 2'nitrooxanilate in comparison to the check gametocide sodium methyl arsenate was studied for selective induction of male sterility on the rice variety Pusa 150 at two concentrations and three stages of.development. Ethyl 4'fluorooxanilate applied with 1500 ppm at stamen-pistil primordia stage or at stage between polIen mother celI formation and meiosis proved most effective with highest polIen and spikelet sterility, widest action spectrum and least phytotoxicity. Gametocides of wide action spectrum ensure higher seed yield and genetic purity. Pilot study on hybrid seed production revealed ethyl 4'fluorooxanilate applied as single spray at stamen-pistil primordia stage to be superior to sodium methyl arsenate with higher percentage seed set, test grain weight and seed yield.