Cover Crop Impacts Fusarium Head Blight Incidence and Mycotoxin Contamination of Cannabis sativa

Hemp has been commercially produced in Kentucky since federal reintroduction in 2018. Fusarium head blight (FHB) is among the most detrimental diseases encountered in Kentucky hemp production. Growers are heavily reliant on cultural management practices to manage FHB of hemp, as resistant cultivars have not been identified and fungicide options are limited. A 2-year multisite field trial was conducted in 2024 and 2025 to determine whether cover crop preceding hemp influenced Fusarium graminearum inoculum load and FHB incidence as well as mycotoxin contamination. Hemp that was no-till planted following a wheat cover crop was exposed to more inoculum than hemp no-till planted into mustard or planted following conventional tillage. In addition, the hemp following wheat had the highest levels of FHB incidence and F. graminearum DNA and mycotoxins in the harvested grain. The mycotoxin contamination levels observed in 2024 were above the advisory limits set for other crops. The results from this study indicate that cultural management practices such as tillage or cover cropping can have significant impacts on FHB in hemp production.