Analysis of Control Efficacy for Five Fungicides on Potato Late Blight

Control efficacy of five fungicides on potato late blight was determined in field experiment.The five fungicides had obvious effects on potato late blight control and increased yield.The best fungicide was Fluopicolide,followed by Mandipropamid,Chlorothalonil,Cymoxanil + mancozeb and Matrine.Yield was increased by 62%-155% compared with control,and tuber rot percentage was only 1.20%-8.09%.According to the test curve of disease development,all of the five fungicides used in the prophase of disease development could achieve a significant control effect.In the anaphase of disease development,however,Fluopicolide and Mandipropamid were recommended.Each fungicide should be used alternatively to avoid resistance to fungicides.