The short-list of eleven chemical hybridizing agents (CHAs) showing 98% or more induction of male sterility
were identified following application at the pre-meiotic stage of wheat. Among ethyl oxanilates, 4-fluoro (CHA
A1), 4-bromo (CHA A2), 4-trifluoromethyl (CHA A5), and 4-cyano (CHA A3) derivatives; and among pyridones,
4-chloro (CHA B3), 4-fluoro (CHA B1), 4-bromo (CHA B2), and 4-trifluoromethyl (CHA B6) derivatives were
the most promising. These agents showed no adverse effects on plant growth and yield. Ethyl 4-fluoro oxanilate
(CHA A1) was tested on 29 wheat genotypes at 1500 ppm and induced 99.76±0.37% male sterility. Ethyl 4-fluoro
oxanilate residues were non-detectable in grain and husk and thus appeared to have no lasting residue effects
