MANEJOS DE INDUÇÃO DE RESISTÊNCIA ALTERAM ARQUITETURA, COMPONENTES DE RENDIMENTO E PRODUTIVIDADE DA SOJA

Abstract

The present study analyzes different induced resistance management strategies in soybean and shows that combinations of resistance inducers and fungicides can significantly alter plant architecture, yield components, and productivity under typical Cerrado conditions. The main objective was to evaluate induced resistance management strategies, applied alone or in association with fungicides, integrating univariate and multivariate analyses to identify which structural and productive variables contribute most to yield. The experiment was conducted in a randomized complete block design with four management strategies (ISR1–ISR4) applied to the cultivar Brasmax Olimpo IPRO. Products were applied at vegetative and reproductive growth stages, and the evaluated variables included structural traits (branching, number of nodes, plant height, and stem diameter), reproductive traits (pods by seed-class, seeds per pod, total pods and grains), and yield. Data were analyzed using descriptive statistics, PCA, LASSO, and path analysis. The results indicated that ISR1 and ISR2 promoted greater vegetative vigor, increased numbers of pods with three and four seeds, and higher yields (up to 70.09 bags ha⁻¹). ISR3 resulted in a more compact architecture and lower yield, whereas ISR4 showed intermediate performance. Path analysis identified P3S, P4S, BRN, MNN, PLH, and TPD as positive contributors to yield, while excessive increases in TSD and GPP had negative effects. It is concluded that management strategies that balance vegetative vigor with a high proportion of three- and four-seeded pods, such as ISR1 and ISR2, are more efficient for maximizing productivity, reinforcing the importance of integrated approaches that align plant health, architecture, and reproductive efficiency.