SENSIBILIDADE DE ISOLADOS DE Fusarium spp. CAUSADORES DA SÍNDROME DA MORTE SÚBITA DA SOJA À MISTURA FLUXAPIROXADE + PIRACLOSTROBINA

Abstract

Soybean sudden death syndrome, caused by Fusarium species, represents one of the major phytosanitary challenges affecting the crop. This study aimed to characterize Fusarium spp. isolates regarding their sensitivity to the fluxapyroxad + pyraclostrobin mixture by evaluating mycelial growth, area under the mycelial growth progress curve (AUMGPC), mycelial growth rate (MGR), and EC50. A total of 44 isolates collected from Goiás State, Brazil, were analyzed. The results revealed high phenotypic variability, with a predominance of sensitive isolates, along with the presence of moderately sensitive and insensitive subpopulations, indicating an early shift in sensitivity. AUMGPC was the most representative parameter of overall isolate behavior. Although the fungicide mixture still shows good average efficacy, continuous monitoring and the adoption of integrated management strategies are recommended to preserve its effectiveness over time.