Potato Solanum tuberosum - Tubers roots and leaves.

Potato (Solanum tuberosum)

Early blight on potato. On potato tubers, early blight results in surface lesions that appear a little darker than adjacent healthy skin. Lesions are usually slightly sunken, circular or irregular, and vary in size up to 1.9 cm in diameter. There is usually a well defined and sometimes slightly raised margin between healthy and diseased tissue. Internally, the tissue shows a brown to black corky, dry rot, usually not more than 6mm. Deep cracks may form in older lesions.

Early blight on potato leaf. Note concentric rings on spots.

Late blight on potato tubers.

Bacterial wilt of potato - symptoms in the tuber

Bacterial wilt symptoms on potato plants. The first visible symptom on foliage is a wilting of the leaves at the ends of the branches during the heat of the day with recovery at night. As the disease develops, a streaky brown discolouration of the stem may be observed on stems 2.5 cm or more above the soil line, and the leaves develop a bronze tint. No yellowing is observed with bacterial wilt ? it?s a sudden death.

Potato X potexvirus

Potato Y potyvirus

Damping-off of potato

Secondary infection to potato tubers in storage due to damage by the potato tuber moth.

Potato tubers damaged by the potato tuber moth.