Common Signs and Symptoms of Dry Rot
Signs of dry rot are an internal brown or black coloured rot of the potato, which as the name suggests, is usually dry, often developing at an injury to the tuber such as a bruise or cut. The potato’s skin will become characteristically wrinkled in concentric rings around the infected area with blue, pink or white pustules present.
Common Causes and Conditions of Dry Rot
Dry rot is soil borne, caused by fungus – normally during the lifting and grading stages.
Storage in warm, humid conditions can encourage dry rot.
Affected / Vulnerable Varieties
A potato variety which tends to be more susceptible to dry rot is Arran Comet, but it can affect all varieties.
Control of Dry Rot
Cultural and Methods:
Plant only non diseased seed and avoid the risk of mechanically damaging and wounding the tubers during grading and planting.
Chemicals and Pesticides:
Thiabendazole and imazalil, when applied quickly after lifting offer some control against dry rot.