Induction of male sterility in wheat and barley by 2-chloroethylphosphonic acid (ethephon)

Emphasis has been directed towards the potential use of ethephon (2-chloroethylphosphonic acid) as a possible gametocide for induction of male sterility. Currently ethephon has been used experimentally as a male gametocide on both wheat and barley. The purpose of this research was to induce male sterility in winter wheat (Triticum aestivum L. em Thell), and winter barley (Hordeum vulgare L.) with foliar applications of ethephon. The field study was conducted at the Plant Science Field Laboratory, Knoxville, Tennessee. Ethephon was foliarly sprayed on Arthur wheat and Volbar barley, at 0.00, 0.10, 0.20, and 0.40 percent active ingredient when the plants were in early, mid-, and late boot stages. The most effective level was 0.40 percent ethephon in early, mid-, and late boot for Arthur wheat, and early, and late boot for Volbar barley. Concentration, stage, and concentration*stage interaction were significant for all variables except for seed weight. No concentration, stage or concentration*stage interaction occurred for seed weight. However there were significant differences among concentrations and stages which directly influenced male sterility. All ethephon treatments resulted in reduced plant heights and lodging. There was no apparent reduction in female fertility as a result of the treatments. The results of this research indicated that ethephon might have possibilities as a rapid and easy means of hybridization in wheat and barley.