Abstract:

To evaluate the field control effects of several chemical control agents on potato late blight in Matou Town of Tancheng County, Linyi City, Shandong Province, 687.5 g/L fluopyram-penoxifen wettable powder, 72% mancozeb-manganese zinc, 42.8% fluopyram-iprovalent wettable powder, and 10 billion/g Bacillus subtilis biological preparation were selected, and a control group and treatment groups were set up, and the incidence index, control effect, and yield were monitored. The results showed that the 687.5 g/L fluopyram-penoxifen wettable powder had a significant control effect on the disease. In 2020, the incidence index was 3.21, 5.13, and 6.02 after three applications of the treatment, with an average control effect of over 80% and a maximum of 85.14%, and an increase in yield of 27.9%. In 2021, the incidence index was 2.95, 4.75, and 5.45 after three applications of the treatment, with an average control effect of over 84% and an increase in yield of 26.0%. The 42.8% fluopyram-iprovalent wettable powder had a slightly lower control effect but was better than other pesticides. The importance of selecting control agents based on regional specific conditions was emphasized, and fluopyram-penoxifen wettable powder was recommended as the preferred control agent for late blight of potato in the study area. The research results provide scientific control guidelines for farmers.

Key words: potato late blight, chemical control, drug screening, disease control efficacy, sustainable development, yield increase