There are several things that hemp grower should keep in mind as they begin to prepare for hemp harvest.
The most important thing is for growers to make sure they schedule a pre-harvest sampling with the Alabama Department of Agriculture and Industries (ADAI). The ADAI will sample and analyze plants from each hemp plot to verify that they do not contain more than 0.3 percent total THC. Crops above the 0.3 percent THC threshold will be destroyed. Following the ADAI’s sample, growers have 14 days to harvest the plants. If harvest is not complete in this timeframe, a new harvest (or destruction) request must be submitted to ADAI. A harvested crop cannot be moved until ADAI issues a permit to move the plant material.
The majority of hemp in Alabama is being grown for cannabinoids (CBD) in the flowers and will be harvested by hand. It is important to be prepared with a plan in place for manual harvest when the plants are ready. Hand harvesting will require adequate time and people based on the size of the field. If the crop is not harvested in a timely manner, growers risk yield or quality loss with increased disease issues.
Quality and price received for harvested hemp can be impacted based on handling and drying once the hemp is harvested. Handling methods vary widely, but it is important that growers have a plan developed before they begin harvesting. Custom drying and/or a processor that accepts wet material may be an option for some growers, but that could result in higher production costs or lower returns from the processor. If growers plan to dry the hemp on their farm, they should make sure they have the correct license through ADAI for the storage facility.
Do not leave hemp in the field to dry down. Hemp should be dried in a covered facility with adequate spacing and air flow to reduce potential for mold growth. Be aware that hanging hemp plants upside down can lead to moisture being trapped in the center. Moisture levels of dried material accepted for processing can vary, so be sure to check with processors for specific requirements.
Recent rains may prove problematic for hemp nearing harvest. Mature hemp plants become heavy if they are wet. This can lead to losing branches or entire plants to lodging. Wet plants are also a concern because of mold.
Diseases have been common in hemp production this year. The diseases that have been observed include
- Southern blight
- phoma canker
- hemp leaf spot
- fusarium canker
Fusarium bud rot has now become an issue. Fusarium colonization of flower buds generally occurs during the later stages of flower development and can be manifested as a pre-harvest or post-harvest bud rot. The fungus is spread by air currents and wind-blown rain, which the state has received plenty of recently. This is a serious disease as it may result in contamination by Fusarium mycotoxins. The other diseases listed above can all cause dieback that will also affect flower buds. It is best to leave these flowers in the field or otherwise keep them separate from non-damaged flowers. Think about it this way, no grower would not harvest diseased or damaged tomatoes.