Benefits of chemical control of white mold on dry beans
2008
Vieira, R..F., Empresa de Pesquisa Agropecuária de Minas Gerais, EPAMIG, Brasil | Paula, T.J., Empresa de Pesquisa Agropecuária de Minas Gerais, EPAMIG, Brasil | Teixeira, H., Empresa de Pesquisa Agropecuária de Minas Gerais, EPAMIG, Brasil
Испанский язык; кастильский. One of the most devastating diseases of dry beans in irrigated areas in Brazil is white mold caused by Sclerotinia sclerotiorum (Lib.) de Bary. The purpose with this study was to quantify the yield increase owing to fungicide applications on dry beans sown in a field infested by S. sclerotiorum. Eleven consecutive yearly experiments were carried out in the same area comparing the intensity of disease on untreated plants with plants treated with fluazinam. This fungicide (0.5 L/ha) was applied twice at flowering onset and 10 days later. The trials were installed on April or May (fall) and were sprinkler irrigated weekly with a water volume of approximately 50 mm. Fungicide was applied by a backpack sprayer (500 L/ha). The plants were rated for severity of white mold on a scale of 0, 1, 2, 3, and 4 representing 0, 1-25%, 26-50%, 51-75%, and 76- 100% of stems, branches, and pods with disease symptoms. Severity values were transformed in the McKinney index according to this equation: _» (score x number of plants with this score) / (total number of plants x greater score) x 100. Average disease severity in the untreated plants was 53.4% and incidence was 73.4%; in the treated plants they were 28.9% and 51.5%, respectively. As a result of the disease reduction by the fungicide, yield was increased between 3.1% and 118.6%. Dry bean yields of untreated plants varied from 1040 to 2369 kg/ha. Plants that received fungicide applications yielded between 1744 and 2968 kg/ha.
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