Mistura de produtos fitossanitários: compatibilidade físico/química e fitotoxicidade na cultura da soja

Abstract

Soybean (Glycine max) is the crop that occupies the largest area during the summer harvest and is also the main Brazilian commodity. However, several factors can affect the development of the crop and compromise its production, such as pests, diseases and weeds. Considering that these factors normally occur simultaneously in the crop, the mix of plant protection products in the spray syrup is used by most soy producers. The objective of this work was to evaluate the physical and chemical compatibility of phytosanitary products in tank mix, herbicides, insecticides and fungicides and their effect on soybean crop. The experiments were conducted in a laboratory and greenhouse at the Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, from April to November 2018. The experimental design was completely randomized, with four replications. The treatments were different mixtures of phytosanitary products, herbicides mixed with fungicides and insecticides separately, glyphosate, Finale, 2,4-D DMA and 2,4-D choline, fungicides, Fox®, Elatus® and Aproach® Prima and insecticides, EngeoTM Pleno, Nomolt® 150 and Decis® 25 EC, tested for physical and chemical compatibility and application effect on soybean crop. The variables analyzed in the laboratory were: physical stability of mixtures, pH and electrical conductivity and variables analyzed in greenhouse: phytotoxicity, SPAD index, height, leaf area and aerial dry matter. The results show that even though there is no perfect stability in certain mixtures, some measures could be taken, such as continuous stirring of the mixture in the spray tank. The alkalinity generated in the Finale + Elatus® and 2,4-D DMA + Elatus® blends may compromise the effectiveness of one or both products. The phytotoxicity symptoms observed in soybean plants were very mild to moderate. The mixtures did not affect the chlorophyll, height, leaf area and shoot dry matter variables. It is concluded that the mixtures of the different phytosanitary products can be carried out in the soybean crop, only it is necessary to adopt some measures to avoid possible control failures of the biological target.