Cannabis greenhouse disease diagnosis and integrated management, including powdery mildew, Botrytis, root disease, HLVd, sanitation, irrigation, airflow, and post-harvest microbial risk.
Diseases
Botrytis / Gray Mold
Botrytis cinerea can colonize senescent or injured tissues and cause destructive flower rot under favorable conditions. Internal flower damage can be advanced before surface sporulation is obvious.
What to look for
- Localized browning, softening, or collapse within flowers
- Gray-brown sporulation under suitable conditions
- Dead leaf tips or damaged tissue embedded in dense flowers
- Rapid progression in humid, poorly ventilated microclimates
Important look-alikes
- Natural senescence
- Mechanical bruising
- Other flower molds
- Localized desiccation
How to confirm
- Inspect inside affected flower clusters rather than only the surface
- Use magnification for characteristic fungal structures when possible
- Record humidity, condensation, airflow, and recent wetting events
Management principles
- Remove affected material carefully to reduce dispersal
- Correct moisture and airflow problems
- Do not retain visibly moldy harvested material for consumption
Prevention
- Keep flowers dry
- Avoid persistent condensation
- Maintain airflow through dense canopies
- Sanitize dead tissue and plant debris
- Inspect frequently late in flowering
Visual study guide
- Internal flower-rot cross section
- Early versus advanced Botrytis panel
- Humidity and condensation risk diagram
- Safe inspection workflow
Evidence & further reading
Sources connected to this lesson
These references support specific biological, diagnostic, environmental, or process concepts used in this lesson. They are not a substitute for crop-specific testing or local regulatory guidance.Cannabis inflorescence microbial loads, microclimate, airflow, handling, drying method, moisture, water activity, and post-harvest risk factors.