Estudo a campo dos componentes de rendimento e da viabilidade econômica da aplicação preventiva de fungicidas V0 na cultura da soja

Abstract

Soybean (Glycine max L. Merrill) is one of the most important agricultural crops in Brazil and is highly affected by phytosanitary and environmental factors throughout its production cycle. This study aimed to evaluate the effect of V0 application of a chemical fungicide and a biological fungicide on agronomic traits, grain yield, and economic viability of different soybean cultivars. The experiment was conducted during the 2025/2026 growing season in a commercial field located in Chopinzinho, Paraná State, Brazil, using a randomized complete block design arranged in a 3 × 3 factorial scheme with four replications. Three soybean cultivars (NA5909, Brasmax Cromo, and Brasmax Trovão) were evaluated under the following treatments: Trifloxystrobin + Tebuconazole, Bacillus pumilus, and an untreated control. The assessed variables included first pod insertion height, plant height, number of pods per plant, grain yield, thousand-grain weight, and economic return. During the crop cycle, two drought periods lasting 18 and 17 days occurred during reproductive stages, negatively affecting yield potential. V0 application increased thousand-grain weight in all cultivars. In the cultivar Cromo, Bacillus pumilus promoted higher grain yield and thousand-grain weight than the control treatment. In the cultivar Trovão, both treatments significantly increased grain yield and thousand-grain weight. For cultivar NA5909, although increases in thousand-grain weight were observed, no significant differences in grain yield were detected. Economic analysis demonstrated positive returns from the treatments, especially for Bacillus pumilus in NA5909 and for both treatments in Trovão. The results indicate that V0 application can contribute to maintaining soybean performance under drought stress conditions, mainly by improving grain filling and yield.