See:
Hemp (Cannabis sativa) -Root and Crown Rot
By C. M. Ocamb
Cause The fungus, Fusarium proliferatum, which can survive in plant debris in soil and has a broad host range. This can affect plants in the field, greenhouse, and vegetative propagation set-ups.
Symptoms Plants may wilt and then die. Seedlings may exhibit a damping-off, where the young plant collapses and the stem is brownish. Foliage can take on a yellowish coloration, then leaves turn brown and fall off the plant. There can be a rot in the crown tissues and the pith of stems can appear brownish-to-black in coloration.
Cultural control
- Sanitation practices, such as using clean pots and sterile media, are recommended.
- Avoid high levels of organic matter in planting medium.
- Cleaning planting tools and equipment can help to minimize disease.
- Do not re-use potting media from diseased plants.
Reference Punja, Z.K. 2020. First report of Fusarium proliferatum causing crown and stem rot, and pith necrosis, in cannabis (Cannabis sativa L., marijuana) plants. Canadian J Plant Pathology DOI:10.1080/07060661.2020.1793222.