What causes Potato Blight?
Potato Blight is caused by a fungus Phytophthora infestans. This can also infect other members of the potato family, Solanaceae, such as tomatoes. It spreads by spores that are spread by wind and rain and infect plants under favourable conditions. These conditions are high humidity and a minimum temperature of 10C (50F). Infected tubers from the previous year may be discarded at the edge of the vegetable patch or left in the ground and if conditions are favourable can act as a source of the following year’s outbreak. Symptoms. These first appear as brown or black patches at the tips and margins of leaflets. Under suitable conditions the patches enlarge and the leaflets curl and wither. In moist weather the fungus is sometimes visible as a delicate white growth on the margins of the patches, particularly on the underside of the leaves. Brown patches may also develop on the stems and the disease can spread rapidly to all aerial parts of the plants, resulting in collapse. Tubers (the actu
