Survey of Fusarium Diseases in Kentucky Floral and Grain Hemp

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 despite some volatility in the markets. Emerging threats to hemp production in Kentucky and the Southeast are Fusarium bud blight in floral hemp and Fusarium head blight in grain hemp. During the 2020 and 2021, severe losses, some as high as 100%, resulted from bud and head blights.  Necrotic floral tissues and seed heads were confirmed infected with F. graminearum, F. avenaceum, F. incarnatum-equiseti species complex, and F. sporotrichioides. Simultaneously, postharvest material was sampled from grower barns and storage units.  In addition to the species documented in fields, F. armeniacum, F. fujikurio, F. luffae, and F. verticilloides were also confirmed.  Many of these species are also 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.  This survey provides critical information as the hemp industry in Kentucky becomes established and markets stabilize.  Understanding of frequency and distribution of Fusarium diseases is the first step in making management recommendations and protecting grower yields.