Avaliação do uso de bioinsumos no cultivo da soja

Abstract

Soybean cultivation (Glycine max (L.) Merrill) is of great importance in Brazil and worldwide. In southwestern Paraná, this commodity is planted in several locations and is often the main source of income. Over the years, soybean cultivation has faced challenges related to climate variability and the increase in pests and diseases, such as Asian rust, caused by the fungus Phakopsora pachyrhizi, brown spot (Septoria glycines), target spot (Corynespora cassiicola) and the etiological agent Cercospora kikuchii, causing purple spot on seeds. The management of these and other diseases is essential when it is desired to exploit the genetic potential of soybean cultivars, increasing productivity. Thus, among the management methods, chemical application has been the most used for several years, through chemical fungicides. However, this practice may be inefficient due to resistant pathogens. An alternative is the use of biological products or also called bioinputs. Thus, the aim of this study was to evaluate five commercial bioinputs based on: Bacillus subtilis WG, Bacillus subtilis EC, Bacillus velezensis EC, Corynebacterium glutamicum metabolite and orange peel terpene, at different doses (0.75 kg/ha, 0.5 l/ha, 0.5 l/ha, 0.05 l/ha and 0.5 l/ha, respectively) to evaluate their efficiency in the management of foliar diseases that affected soybean. The experiment was carried out at the UTFPR experimental farm, Dois Vizinhos campus, during the 2024/2025 harvest, where the design used was randomized blocks, with 13 treatments and 4 replicates each, with T0 being the control without application, T1 the chemical standard, from T2 to T9 the mixture of bioinputs in different combinations to the chemical standard, and from 10 to T12 isolated applications of the bioinputs Bacillus subtilis WG, Bacillus subtilis EC and Bacillus velezensis EC. The application program for the different treatments was followed in five applications, the first in V0 (preventive application in V4) and the last four in V0+15D, V0+30D, V0+45D and V0+60D, respectively. The incidence and severity of the diseases were evaluated before application in the last four applications and one 15 days after the last application.In the post-harvest period, the height of insertion of the first pod, plant height and yield components (number of nodes, number of pods, number of grains per pod, thousand grain weight (PMG) and productivity) were quantified. The data were statistically analyzed using the Skott-Knott test, in addition to calculating the area of action below the disease progress curve (AUDPC). This study showed that the application of the tested bioinputs resulted in lower severities, consequently smaller areas of action below the disease progress curve and increases in soybean productivity. Isolated and combined applications resulted in lower AACPDs and higher yields when compared to the control treatment and chemical standard, respectively. Statistically, there were no significant differences for the yield components evaluated.