Fungicidas sistêmicos e protetores no controle de ferrugem asiática da soja e efeitos sobre a produtividade da cultura

Abstract

One of the main diseases of the soybean crop is the Asian rust, and the use of chemical control, and its success, is often dependent on the prevailing climatic conditions. Over the years, because they are used several times during the cycle of a crop, fungicides end up presenting a reduction in efficiency in the control of a particular phytopathogen. Thus, the objective was to evaluate the efficacy of products based on prothioconazole combined or not with multisites in the control of Asiatic rust. The experiment was conducted in the Experimental Area of the UFFS - Erechim Campus in the 2021/22 harvest, in a randomized block design with 4 repetitions and 13 treatments; the cultivar BMX Ativa was used. The treatment T1 represented the control without fungicide application, and the other treatments (T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, and T13) received fungicide application according to the experimental protocol. The severity of the disease, yield components and productivity of the cultivar were evaluated. The greatest control of the disease and the highest yields were observed with three applications of fungicides containing mancozeb and chlorothalonil along with the systemic ones. The T5 treatment excelled the others, providing an 80%+ control of the Asian rust and productivity of 4438.18 kg ha-1.