Leath, S., and Bowen, K. L. 1989. Effects of powdery mildew, triadimenol seed treatment, and triadimefon foliar sprays on yield of winter wheat in North Carolina. Phytopathology 79:152-155. Wheat plots were established in central and eastern North Carolina in the yields. Area under the powdery mildew curve was negatively correlated falls of 1985 and 1986 to determine yield reduction caused by Erysiphe with yield; the correlation coefficient averaged -0.55 across four graminis f. sp. tritici on winter wheat cultivars Saluda and Coker 983. environments. No clear associations between disease and various yield Check plots were compared with plots kept nearly disease-free with three to components were detected. Regression models were constructed, and yield four foliar applications of triadimefon. The efficacy of triadimenol for reductions of approximately 17% were observed in Saluda when disease mildew control when applied as a seed treatment, with or without different severity reached 10% on the flag leaf by heading. Powdery mildew can limit triadimefon foliar spray schedules, also was determined. Significant disease yield in modern soft red winter wheat cultivars, although current levels of control resulted from foliar applications of triadimefon on both cultivars; resistance in certain cultivars are sufficient to prevent large yield however, the only consistent yield reductions were observed with Saluda. reductions. Triadimenol seed treatments lowered mildew severity and increased grain