Climatic risk for Asian soybean rust occurrence in Mato Grosso, Rio Grande do Sul and Parana states /Risco climatico para ocorrencia da ferrugem asiatica da soja no Mato Grosso, Rio Grande do Sul e Parana

Asian soybean rust is a primary factor affecting soybean production. Climate risk knowledge optimizes agricultural management, reduces pesticide use, and promotes environmental sustainability. The objective of this study was to evaluate the climatic risk of the occurrence of Asian soybean rust in the states of Mato Grosso, Rio Grande do Sul, and Parana, Brazil, verifying the months with temperature and relative air humidity that are more favorable for disease development. Hourly meteorological data were obtained from the National Institute of Meteorology, collected from 36 automatic weather stations in Mato Grosso state, 44 in Rio Grande do Sul state, and 26 in Parana state, from the beginning of the operation until December 31, 2021. The climatic risk values for Asian soybean rust occurrence were calculated daily, obtained by the product of the response functions to leaf wetness duration and air temperature during this period. The average total climatic risk of Asian soybean rust occurrence in Mato Grosso, Rio Grande do Sul, and Parana states, was 44, 30, and 36%, respectively. Relative air humidity was the meteorological element with the greatest climatic risk for the development of the disease in the states of Rio Grande do Sul and Parana, Brazil, and air temperature was the most limiting, the opposite was observed for the state of Mato Grosso, where air temperature was favorable and relative air humidity was more limiting. Key words: Glycine max (L.), disease forecasting systems, air temperature, relative air humidity A ferrugem-asiatica da soja e um dos principais fatores que afetam a producao de soja. O conhecimento dos riscos climaticos otimiza o manejo agricola, reduz o uso de agrotoxicos e promove a sustentabilidade ambiental. O objetivo deste estudo foi avaliar o risco climatico para a ocorrencia da ferrugem-asiatica da soja nos Estados de Mato Grosso, Rio Grande do Sul e Parana, Brasil, verificando os meses com temperatura e umidade relativa do ar mais favoraveis ao desenvolvimento da doenca. Os dados meteorologicos horarios foram obtidos atraves do Instituto Nacional de Meteorologia, coletados de 36 estacoes meteorologicas automaticas do estado de Mato Grosso, 44 no Rio Grande do Sul e 26 no Parana, desde a data de inicio de funcionamento ate 31 de dezembro, 2021. Os valores de risco climatico para a ocorrencia da ferrugem-asiatica da soja foram calculados diariamente, obtidos pelo produto das funcoes de resposta a duracao do molhamento foliar