Screen Varieties Resistance and Fungicide to Early Blight of Processing Tomato

Fifteen processing tomato varieties were identified for the early blight resistance identification in the farm.The results showed that there were no resistant varieties,and 6 varieties were tolerable account for 40%,9 varieties were susceptible accounting for 60%.The control efficacy of twelve fungicides to early blight of processing tomato with experiments of indoor toxicity trials and field trials were compared.Indoor toxicity trials shows that Cymoxanil mancozeb 72% WP was the most effective fungicide against the pathogen with EC50of 8.1 μg/mL,Mancozeb 70% WP,Metalaxyl·mancozeb 58% WP,Difenoconazole 10% WP,and others with a low effect.Field plot trials showed that the control effects of Cymoxanil mancozeb 72% WP was the highest,the control efficacy reached to 81.2%,Mancozeb 70% WP,Metalaxyl·mancozeb 58% WP and Difenoconazole 10% WP in turn,with the average control efficacy of 73.1%,71.0% and 61.0%,respectively.