Bacillus spp. no controle de doenças foliares de final de ciclo na cultura da soja

Abstract

Soybean (Glycine max), is the main agricultural crop in Brazil, and has been demanding adjustments in cultivation for a sustainable production process in recent years. In this sense, studies are needed considering the use of biological products, as sources of alternative controls, which can be used in an integrated manner with fungicides in the management of leaf diseases in soybean crops. The objective of this work is to evaluate the potential of a commercial product based on Bacillusin the control of leaf diseases at the end of the cycle -DFC (anthracnose, septoriosis, cercosporiosis and target spot). The work was carried out at the experimental station of the Federal Technological University of Paraná (UTFPR) Campus Dois Vizinhos, during 2020 and 2021. There were 7 treatments, consisting of: 1-control (without applications); 2-treatment with systemic fungicides (Epoxiconazole, Fluxapiroxade, Piraclostrobina and Bixafem, Protioconazole, Trifloxistrobina); 3-multisite fungicide (Mancozeb and Clorotalonil); 4-systemic + multisite; 5-Bacillus based product (B. subtilis; B. pumilus, B. amyloliquefaciens); 6-two initial applications of Bacillus and two subsequent applications of systemic fungicide; 7-associated application of systemic fungicide and Bacillus. For all treatments, there were four applications, the first being carried out at the phenological stage V5 (5 true leaves) and the others at 15-day intervals. The experimental design used was that of randomized blocks, in 4 replicates with plots of 24m2. The variables evaluated were the incidence and severity of end-of-cycle diseases, constituting the Area Below the Disease Progress Curve and productivity. The results showed that the use of the commercial product based on B. subtilis; B. pumilus, B. amyloliquefaciens has action on end-of-cycle diseases, and when positioned only Bacillus reduced the severity of DFC, differing from the control, however with less efficiency than fungicides. However, when two initial applications and two fungicides were carried out, or in the four associated applications, it showed good performance in reducing diseases and increasing productivity.