A Field Experiment on Chemicals Effects to Control Potato Late Blight

Field experiment was carried to screen the optimal chemicals,10% cyazofamid SC,50% Fluazinam SC,44% cymoxanil-chlorothalonil WP,50% dimethomorph WG,and 58% metalaxyl-mancozeb WP were used to control potato late blight by foliage spray.Result showed that,among the 5 chemicals,50% Fluazinam SC was the most effective one,control efficiency reached 81.19% after 3 sprays and potato yield increased 8.11% compare with control.The following was 58% metalaxyl-mancozeb WP,with 75.98% of control efficiency after 3 sprays and yield increased 6.23%.50% dimethomorph WG ranked third with 70.04% of control efficiency and yield increased 6.17%.Three of them could be applied alternately to control late blight in potato production.