Manejo de manchas foliares no cultivo da soja com diferentes fungicidas na aplicação zero

Abstract

Soybean (Glycine max) is one of the most important commodities in Brazil. The main factors limiting its production are diseases, with approximately 40 diseases identified in the country, caused by fungi, bacteria, nematodes, and viruses. Foliar spots are common at the beginning of soybean development, and since pathogens can be present from the beginning of cultivation, preventive management is employed with application in the vegetative phase, 30 days after sowing (zero application). This study aims to evaluate the effectiveness of different fungicides from the chemical groups triazoles, strobilurins, multisites, and biological control in controlling foliar spots through zero application. The methodology followed the recommendations of the Ministério da Agricultura, Pecuária e Abastecimento (MAPA-Brazil) according to Normative Instruction No. 13 of 2011, with a randomized block design (DBC), 7 treatments, and 5 replications, totaling 35 plots. The treatments, applied 30 days after sowing at the V3 phenological stage, included a control with no application, Bacillus amyloliquefaciens, Picoxystrobin + Ciproconazole, Chlorothalonil, Saccharomyces cerevisiae, Picoxystrobin + benzovindiflupyr, and Tebuconazole + Trifloxystrobin. Disease incidence and severity, live canopy coverage index, and productivity variables were evaluated. Treatments with strobilurins + triazole (Picoxystrobin + Ciproconazole) and Saccharomyces cerevisiae yeast were more effective in disease control and increasing productivity.