Late blightCaused by: Phytophthora infestans
Problem Category: Fungal Disease
Symptoms: Late blight affects all aerial parts of the tomato plant; initial symptoms of the disease appear as water-soaked green to black areas on leaves which rapidly change to brown lesions; fluffy white fungal growth may appear on infected areas and leaf undersides during wet weather; as the disease progresses, foliage becomes becomes shriveled and brown and the entire plant may die; fruit lesions start as irregularly shaped water soaked regions and change to greasy spots; entire fruit may become infected and a white fuzzy growth may appear during wet weather.
Comments: Can devastate tomato plantings.
Management: Plant resistant varieties; if signs of disease are present or if rainy conditions are likely or if using overhead irrigation appropriate fungicides should be applied.
Control: mix 5kg ash in 50 litre of water and spray the solution to control the late blight