In Anton Rosenfeld shares advice about how to spot blight on your vegetable crops – and what to do about it.
Blight is a virulent fungus that mainly attacks tomatoes and potatoes – and can destroy plants very quickly. It’s prevelant from June onwards, and tends to get worse later in the growing season. Most commonly, when people talk about ‘blight’, they are referring to late blight which is caused by the fungus Phytopthora infestans. There’s also an early blight that is a totally different fungus, Alternaria spp., and less commonly encountered.
The fungus is recognisable as a dark, penny sized lesion on the margin of the leaf, that rapidly spreads across the plant. It’s not to be confused with various nutrient deficiencies such as magnesium that cause small spots on the leaves. You may also see it on the stems, which turn dark and rot, then when it reaches the fruit, they turn a sickly grey colour.
https://www.gardenorganic.org.uk/news/way-to-beat-the-blight
