Definition - What does Late Blight mean?
Also known as potato blight, late blight is a plant disease that is commonly caused by a fungus known as Hytophthora Infestans. While it more commonly infects potatoes, late blight can also affect tomatoes.
Symptoms of late blight don’t usually manifest until the later stages of the disease.
According to historians, late blight was the main cause of the European famines that took place in the 1800s. In addition to late blight there are several other types of blights that affect plants, including early blight and bud blight.
MaximumYield explains Late Blight
In most cases of late blight, the symptoms start to appear prior to the blossom. Older and lower leaves may sport gray-green spots and may appear water-soaked.
As the blight progresses, these spots may darken and form a white coating across the undersides of the leaves. Unlike other types of fungal ailments, late blight does not overwinter on garden trash or in the soil but is first introduced through seeds, transplants, or diseased tubers. Humid and warm climates tend to encourage the condition to spread.
Treating late blight often involves the complete destruction of all potato and tomato debris. Gardeners should avoid overhead irrigation and only water the plants early in the morning. It is also recommended to maintain plenty of space between the crops to improve air circulation.