The response of ‘Era’ (tolerant) and ‘Coteau’ (susceptible) hard red spring wheat (Triticum aestivum L.) to CGA-82725 2-propynyl ester of {2-[4- [(3,5-dichloro-2-pyridinyl)oxy] phenoxy] propanoic acid} was determined in field and greenhouse evaluations. Era wheat was most susceptible to CGA-82725 applied at early jointing through the boot stage. Coteau wheat was most susceptible at die two-leaf stage and between early jointing through spike emergence. Coteau was injured more than Era wheat as the CGA-82725 rate was increased from 0.14 to 0.28 kg ai/ha. Wheat grain yield reductions were greatest when CGA-82725 was applied at the early jointing through boot stage for both cultivars and averaged 73% of the control. Absorption and translocation of 14C-CGA-82725 were similar and increased over time regardless of cultivar. Most of the absorbed 14C remained in the treated leaf in both cultivars.
