1Sinochem Agrochem Co.，Ltd，Shanghai 200002，China；2State Key Laboratory of Creation and Development of Novel
Pesticide，Sinochem Agrochemicals R & D Co.，Ltd.，Shenyang 110021，Liaoning，China；3Shenyang Research Institute
of Chemical Industry（Nantong）Chemical Science and Technology Co.，Ltd. Nantong 226017，Jiangsu，China
Synergic toxicity of mixture containing fenaminstrobin and propineb at different mass ratios（1∶1，1∶3，1∶5，1∶7，1∶9）on tomato early blight was tested by spore germination method，and field application effect of the mixed fenaminstrobin and propineb 60% WG（mass ratios 1∶9）on tomato early blight was also evaluated. The results showed that the EC50 of fenaminstrobin and propineb to Alternaria solani were 1.514 0 mg·L-1 and 11.988 8 mg·L-1，respectively. The 5 matching mass ratios（1∶1，1∶3，1∶5，1∶7，1∶9）all showed obvious synergistic effects. The results of field experiment indicated that tomato early blight could be controlled by the mixed fenaminstrobin and propineb 60% WG twice every other week during the initial stage of leaf spot occurance，and the recommended dosage was 480-960 g·hm-2.
