Late Blight of Potato
Phytophthora infestans
Potatooomycete
The historically devastating disease behind the Irish potato famine, destroying foliage and tubers under cool, wet conditions.
Symptoms
Water-soaked leaf blotches with white fungal growth on the underside in humid weather, and a granular brown rot in tubers.
Favorable conditions
- •Cool, wet, humid conditions
- •Rapid spread by wind-blown spores over long distances
Management
- 1Apply a preventive fungicide program
- 2Destroy cull piles and volunteer plants
- 3Plant resistant varieties
- 4Avoid overhead irrigation and hill properly to protect tubers
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