Emerging Fusarium spp. causing Head Blight on Hemp in Kentucky

Hemp (Cannabis sativa L.) is a versatile crop that can be used to produce a wide range of products including food, fiber, and medicine. In 2021, U.S. hemp was valued at over $824 million. Emerging threats to hemp production in Kentucky and the southeastern U.S. are head blight in floral and grain hemp. During the 2020 growing season, severe losses, some as high as 100%, resulted from head blights. Necrotic floral tissues and seed heads from research trials were analyzed to confirm species identity and pathogenicity. Previously unreported causal species in Kentucky included F. avenaceum, F. incarnatum-equiseti species complex, and F. sporotrichioides; F. graminearum was also confirmed. These species are known to cause head blight of cereal grains. The mycotoxin production potential of each of these species warrants further studies into the parameters that influence infection and the interaction between these Fusarium spp. and hemp.