POTATO FUNGICIDE STUDY

An experiment to evaluate the efficacy of two clorothalonil formulations (Bravo 720 and Bravo 825), two mancozeb formulations (Manzate 200DF and Dithane F-45), and copper hydoxide (Champ) on potato early blight, late blight, and black dot was planted at the Powell Butte site of Central Oregon Agricultural Research Center on June 7, 1993. No late blight or black dot was observed during the growing season and minimal early blight was noted because of weather conditions. All of the fungicide treatments tested reduced the level of early blight as compared with the untreated check. There were no differences in early blight control among the fungicide treatments. There were no statistically significant differences in yield, specific gravity, or tuber weight among the fungicide treatments.