Root-zone oxygen supply, waterlogging, root respiration, water and nutrient uptake, chronic saturation, root decline, and the overlap between aeration deficit and root-decay pathogens.
Symptom differential
Wet-Media Wilt & Post-Irrigation Droop
A drooping plant in wet media may have impaired root aeration or root disease rather than a water shortage. The timing of wilt relative to irrigation can completely change the differential.
Pattern questions
- Does droop begin or worsen after irrigation?
- How long does the medium remain wet?
- Are roots firm and actively branching or dark, soft, and reduced?
- Does the plant improve as the root zone dries?
Plausible cause categories
- Root-zone hypoxia
- Poor drainage or chronic saturation
- Pythium-associated or other root disease
- High EC
- Less likely true drought when the root zone is demonstrably wet
Discriminating checks
- Measure moisture and dryback rather than watering again by reflex
- Inspect roots and drainage
- Measure root-zone EC and temperature
- Compare plants in faster- and slower-drying positions
Red flags
- Root sloughing or strong decay odor
- Rapid collapse across a shared irrigation system
- Persistent saturation
- No recovery as aeration improves
Visual study guide
- Wet-wilt versus dry-wilt plate
- Post-irrigation timeline
- Root aeration diagram
- Dryback comparison chart
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 greenhouse disease diagnosis and integrated management, including powdery mildew, Botrytis, root disease, HLVd, sanitation, irrigation, airflow, and post-harvest microbial risk.