University of Kentucky (UK) researchers are spearheading the fight against Fusarium head blight (FHB) in hemp crops. This devastating fungal disease threatens the quality and yield of hemp, which is increasingly important for grain, fiber, and cannabinoid production. The research team has uncovered concerning findings, including the potential for cross-infection between hemp and cereal crops, the early onset of infections, and the risk of harmful mycotoxins. Their work aims to develop solutions, such as resistant hemp cultivars and effective fungicide treatments. This critical research is essential for ensuring product safety and quality as hemp becomes more widely used, particularly in the animal feed market. Fusarium, Mycotoxins

Behind the scenes of Fusarium

University of Kentucky (UK) Martin-Gatton College of Agriculture, Food and Environment Extension faculty are leading efforts to control Fusarium head blight (FHB) in hemp. There are several Fusarium species which have recently emerged as a major threat to industrial hemp crops nationwide, and infection by these fungi leads to the devastating disease fusarium wilt.

The significance of hemp begins: grain, fiber, and specializations for the production of cannabinoids Perceived importance As the move to legitimate manufacturing takes shape, disease management becomes a primary focus. Plant tissues in hemp seed heads and floral structures can die due to FHB causing significant reductions in crop quality and yield. A great deal of research will be invaluable in the UK as production increases, especially with hemp being used for animal nutrition

Cross-infection risks

A UK research team has discovered that the Fusarium species infecting hemp are identical with those causing head blight in wheat, barley and other cereal crops. This has serious implications for the risk of inter-infection between hemp and cereal crops in co-grown regions.

Nicole Gauthier, hemp extension plant pathologist and Department of Plant Pathology extension professor, said, “Our early results indicate we need to rethink the crop-rotation combination of hemp and wheat. Possible areas where Fusarium can be transmitted between these crops could affect both their quantity and quality. This underlines the critical necessity of controlling diseases in a systematic manner, as the consequences of cross-infection could cause irreparable damage to hemp and cereal producers alike such sub-clinical or latent infections preclude visual detection.

Mycotoxin Threats – Early Infection Challenges

Fusarium infections can also start up to nine months before visible symptoms show, the UK research team has further reported. This is a major problem for farmers — the virus can quietly spread without alarm until real harm has been done.

Infections can start days before those symptoms show up, which makes spotting them early challenging, Gauthier said. That also means there’s a window for intervention in which the disease could be stopped from continuing to spread.

A second important aspect is the synthesis of secondary metabolites such as DON and T-2 (mycotoxins) in grain by fungi from Fusarium genus. They are compounds central to human and animal health [7, 8], which might raise concern for their presence in hemp especially in case of producers from the animal feed market. “Given the increasing use of hemp in animal feed, it is critical to verify the absence of dangerous mycotoxins in crops,” Gauthier said. “Our study provides compelling evidence for the synthesis of mycotoxins into Fusarium-colonised hemp, but more research is needed to quantify the associated risk,” they write.