Hemp is often considered a disease-free plant. However, no research has been done to determine whether certain pathogens can increase to problematic levels in the field. If disease becomes a significant problem in field-planted hemp, the result can be premature leaf drop, bud decay, dieback, decline, and even plant death. A good sanitation program can help reduce disease in the field. In addition, these practices can reduce the need for chemical controls, which are a limited option for hemp growers. Sanitation can also improve the effectiveness of other cultural practices for managing diseases.
- Remove diseased plant tissues from infected plants.
- Prune affected branches several inches below the point of infection. Make cuts at intersecting branches when possible.
- Discard plants that are heavily infected and those with untreatable diseases, such as root rots and vascular wilts. Dig out entire plants when possible.
- Discard fallen leaves, prunings, and culled plants. Infected plant material should be buried, burned, or removed from the area. Do not compost diseased plant material.
- Plow under fallen leaves to promote the breakdown of leaf tissue. Woody stems do not decay readily and should be removed from fields.
- Remove weeds and volunteer plants to limit alternate hosts and disease spread (Figure 1).
- Hemp Field Sanitation for Small-Scale Plantings (Kentucky Hemp Disease Website)
- Plant Pathology Publication Webpage
By Nicole Ward Gauthier, Extension Plant Pathologist and Kimberly Leonberger, Extension Associate