Leaf and tuber blight (Phytophtora infestans) is the most important disease occurring in potato cultivation. Starting from brown-rotting tubers,spores are spread by wind and rain splash onto leaves and stems.
Leaf and tuber blight [Phytophthora infestans]
The severe epidemic arise from this primary infection and spread is dependent on the weather. Symptoms are first seen in moist-humid weather as white mycelium covering the lower surface of the leaves. The infection then leads to brown spots on the leaves and causes them to dry up (Picture 1). Water can wash spores off leaves and penetrate the soil to infect the tubers (Picture 2). Removing haulm before harvest will help reduce the potential spread od blight to the tubers. With a high amount of damage, it is possible for the entire crop to collapse.