Managing disease of the hemp crop is a key component in bringing a high-quality product to the market! Much of disease management for hemp involves practices that need to be deployed far ahead of the harvest. Practices such as wider plant spacing, variety selection, and crop rotation can all help reducing disease pressure.
While preparation through the aforementioned cultural practices of disease control are often the first line of defense, high disease pressure in your hemp crop may warrant further action. If you begin to see additional pressure from pests, a few immediate measures can be taken including physical removal of infected hemp plant tissues. Depending on severity of disease, individual leaves, branches, or flowers may be removed from the field to reduce the spread and entire plant removal may prove beneficial in some instances. Also, a number of commercially available products registered for hemp could also prove effective for disease control if required, however it is important to follow pesticide labels for rates, frequency, and uses. Click here for a list of EPA approved products and active ingredients registered for use on hemp.
In our region the main diseases of concern include powdery mildew, white mold, gray mold, and various leaf spots. For most accurate identification of these diseases, samples of infected plant tissue can be sent to the UVM Plant Diagnostic Clinic located on the UVM campus. With the proper identification of these diseases, you can then select the appropriate control measures and respond accordingly.
Recent research at UVM Extension is evaluating the efficacy of disease control products in hemp, check out the 2021 On-Farm New England Hemp Pest and Disease Scouting Report. You can read more about UVM Extension NWCS’s most up-to-date research on our Research Results webpage. For more information on our UVM Extension Hemp-related research and outreach please visit our Industrial Hemp webpage. Or, visit our main website (click here) for all things Northwest Crops and Soils!