摘要 : ? 2023 Elsevier LtdGrapevine leaf spot (GVLS) (Pseudocercospora vitis) occurs at the end of the cycle of Vitis labrusca cultivars. A fungicide application program, considering preventive applications, has not been studied to contr... 展开 ? 2023 Elsevier LtdGrapevine leaf spot (GVLS) (Pseudocercospora vitis) occurs at the end of the cycle of Vitis labrusca cultivars. A fungicide application program, considering preventive applications, has not been studied to control GVLS. The objectives of this study were i) to evaluate the effect of fungicide programs, with different application start dates, on GVLS epidemics in the field and ii) to test the efficacy of fungicides in preventative applications to control GVLS in a greenhouse. The field experiment was carried out in the municipality of Campo Largo, Paraná, Brazil, during 2019/20, 2020/21, and 2021/22 seasons of the Bord? cultivar. In each season, six fungicide programs, with different application start dates, and a control, without application, were evaluated and compared. In the greenhouse, grape seedlings were treated with seven different fungicides, and 24 h later they were inoculated with P. vitis. In the field, the maximum asymptote, an important epidemiological parameter, was lower in the treatment with fungicide applications carried out from the 6th (flowering) to the 18th week after budburst (after harvest). This treatment was carried out at fortnightly intervals, rotating the active ingredients copper oxychloride, pyraclostrobin + methiram, and difenoconazole. In the greenhouse, the fungicides mancozeb, chlorothalonil, difenoconazole, and the methiram + pyraclostrobin mixture had control efficacy above 80% in relation to the untreated control. The results suggested that reducing primary P. vitis infections, which can occur from the beginning of the grapevine cycle, is an important strategy for controlling GVLS in the subtropical climate. 收起