Incidence and Distribution of the Fusarium sambucinum Species Complex Associated with Cannabis sativa in Kentucky

Hemp is an emerging crop that is cultivated for a variety of applications. Since commercial reintroduction in 2018, many pathogens and pests that threaten production have been identified, such as Fusarium head blight. The disease causes extensive blighting of floral tissues and presents a mycotoxin contamination risk. During the 2022 growing season, 25 sites were surveyed across 15 different counties to determine the incidence and distribution of toxigenic Fusarium species within the Fusarium sambucinum species complex. Fusarium graminearum was the most isolated species within the complex. The 15-DON chemotype was found to be the predominant F. graminearum population. The F. sambucinum species complex isolation rate varied by site and reached up to 46.6%. Isolation rates were found to be correlated with plant age and calendar day. Management strategies are currently limited for Fusarium head blight of hemp. Data from this survey will help develop future projects and disease management plans regarding spray timings and crop rotation.