Fenhexamid is primarily used as a fungicide in agriculture, especially in the control of Botrytis cinerea, commonly known as gray mold. It is highly effective in protecting fruits, vegetables, and ornamental crops, with significant use in vineyards for managing bunch rot in grapes. The compound works by inhibiting fungal sterol biosynthesis, specifically targeting the 3-keto reductase enzyme, which disrupts cell membrane formation in sensitive fungi. It is often applied as a foliar spray during flowering and fruit development stages due to its preventive and curative properties. Fenhexamid shows strong residual activity and performs well under cool, humid conditions where gray mold thrives. Because of its specific mode of action, it is considered valuable in resistance management programs, typically rotated with fungicides from other chemical classes to reduce the risk of resistant strains. The compound is favored in integrated pest management (IPM) systems due to its favorable environmental profile, low toxicity to beneficial insects, and minimal impact on non-target organisms when used as directed.