Emerging Cannabis sativa and hemp diseases, inoculum sources, field carryover, Neofusicoccum-associated disease, Sclerotinia white mold, southern blight, pathogen spread, and integrated disease-management context.
Diseases
Sclerotinia White Mold
Sclerotinia-associated white mold has been reported in hemp and cannabis production contexts. White fungal growth and hardened survival structures can be important clues, but laboratory confirmation is appropriate when the diagnosis affects crop-removal or site-management decisions.
What to look for
- Water-soaked or collapsing stem and lower-canopy tissue followed by white cottony fungal growth under favorable conditions
- Hardened dark survival structures (sclerotia) associated with diseased tissue when present
- Localized wilt or stem collapse linked to an infected crown or stem section
- Field history involving susceptible crops or persistent soilborne inoculum
Important look-alikes
- Botrytis gray mold
- Southern blight
- Fusarium-associated crown disease
- Mechanical stem collapse followed by secondary saprophytic mold
How to confirm
- Inspect affected stems and crowns for characteristic fungal growth and survival structures
- Document the field or substrate history and distribution pattern
- Sample the active disease margin for laboratory identification
- Do not identify white mold from white mycelium alone
Management principles
- Remove affected material carefully to reduce movement of infected debris
- Reduce prolonged moisture conditions that favor disease where compatible with crop needs
- Account for persistent soil or debris-borne inoculum when planning future crops
- Base site-level decisions on confirmed diagnosis and local agronomic guidance
Prevention
- Review previous crop disease history before outdoor planting
- Remove infected residues rather than incorporating obvious diseased material into clean production areas
- Maintain airflow and avoid persistent canopy wetness
- Scout lower stems and crowns as well as leaves and flowers
Visual study guide
- White mold stem progression plate
- Sclerotia identification close-up
- Sclerotinia versus Botrytis versus southern blight comparison
- Field inoculum carryover diagram
Evidence & further reading