Target Spot Potato Disease

Target spot, aka early blight (Alternaria solani) is a potato disease which attacks older leaves as the plant ages or when the plant is under stress.

Common Signs and Symptoms of Target Spot / Early Blight

Signs of early blight are the appearance of spots and concentric rings on the plant’s leaflets

Early blight’s symptoms can be differentiated from those of late blight by the lack of spores appearing during damp conditions.

Common Causes and Conditions of Target Spot / Early Blight

Early blight or target spot is caused by Alternaria solani, an opportunistic fungus which attacks older leaves once the plant ages.  Tubers that get exposed to early blight spores during harvest can develop a rot called tuber blight after a few months of being kept in storage.

Early blight thrives during spells of hot weather.

Vulnerable / Immune Varieties

There are no particular potato varieties which are vulnerable or resistant to early blight.

Controlling Target Spot / Early Blight

Control of early blight is not usually required in the UK, however the appliance of fungicides as part of a wider blight control strategy can help control spreading of the disease.