3‐Hydroxydecanoic acid as a dual‐action biopesticide for Fusarium head blight in wheat: pathogen suppression and immunity activation

Fusarium head blight (FHB), primarily caused by Fusarium graminearum, poses a significant threat to wheat production, reducing yields and contaminating grains with the mycotoxin deoxynivalenol (DON). Conventional chemical fungicides are increasingly limited by resistance and environmental impact. This study evaluates the efficacy of 3-hydroxydecanoic acid (3-HDA), a natural metabolite, as an eco-friendly biopesticide to manage FHB in wheat. As found, 3-HDA effectively inhibits fungal growth and spore germination in vitro, achieving EC₅₀ values of 295 and 82.5 mg/L, respectively. Field trials showed a 68-98% reduction in FHB severity and DON levels under 1 mg/kg, comparable to triazole fungicides. Mechanistically, 3-HDA activates reactive oxygen species (ROS) within fungal cells, leading to cell death, and boosts wheat immune responses by increasing salicylic acid (SA) levels post-infection. These dual actions highlight 3-HDA as a promising, sustainable alternative to chemical fungicides, aligning with environmental objectives in modern agriculture.