Late blight
potato blight
CLASSIFICATION
Chromista, Peronosporea, Peronosporaceae, Phytophthora, Phytophthora infestans
ABOUT
Late blight is caused by the pathogen Phytophthora infestans, often occurring in tomatoes and potatoes. Typical symptoms are water-soaked gray-green spots on older leaves, large brown blotches on leaves, dry brown foliage, and dark brown spots on fruits.
How to treat?
- Biological
If possible remove and destroy the infected plant. Burn it, toss it into the garbage, or bury it deeply. Do not compost.
- Disease prevention
Use resistant species and cultivars as well as healthy, certified seeds and seedlings.
Rotate crops. Avoid planting sensitive crops in Phytophthora infested soil.
If necessary, use chemical products as a prevention (e.g. copper-based spray, phosphonates). These chemicals may lead to the development of resistant strains.
Disinfect tools, infected flower pots, and hands to avoid disease transmission.