Control effect of potato early blight with different doses of 70% propineb WP

In order to control potato early blight,different doses of 70% propineb WP were sprayed to test the pesticide effectiveness in field.The result showed that potato early blight infection was controlled significantly by 70% propineb WP as a rate of 3 000 g/hm2,and control effect was up to 76.9%.Yield increases of 17.3% were demonstrated when treatment with propineb WP 2 250 g/hm2.The difference of increasing effect on potato yield among different doses was not significant.Take all factors into consideration,the dose of 1 500~2 250 g/hm2 was recommended in production.