Pathogen Information
Cavity spot is caused by parasitic oomycetes Pythium, not a true fungi it is more closely related to brown alge. Typically caused by P. violae and P. sulcatum it exhibits fungi like symtoms such as:
- Horizontal lesions on the roots typical less then a half an inch.
- Can occur anywher along the root but top third is most effected.
- Spots that can merge as disease progresses.
- Leaves will show no symptoms unless the rot has caused the roots to decay.
Environmental Conditions
- Temperature: 70-80°F
- Humidity: Wet soil
- Most effected species: Root vegtables
Disease Progression
Early Stage
Small dots often hard to spot unless washed and examined carfully
Mid Stage
.5" lesions start to form and spread throught the roots
Late Stage
Open sores on the roots allow for secondary infections
Prevention Methods
- Maintain proper plant spacing
- Remove and destroy infected plant debris
- Rotate crops with non-susceptible plants
- maintain a constistant watering schedule and avoid over watering
Treatment Options
- Mefenoxam-based fungicide
- Treat soil with calcium nitrate, bonemeal or Gypsum during growth
- Benificial Mirobials sucha as Trichoderma virens
- Raising the pH above 7 during a non grow seasons can kill of what is in the soil
