Rhizoctonia

Rhizoctonia solani

Symptoms

• Black sclerotia on the tuber
• Abnormally shaped tubers
• Tubers above the ground, close to the stem (mainly in lighter soils)
• Scab-like lesions, ’elephant hide’ skin, growth cracks, blind eyes and/or malformed tubers
• Dry cores slightly sunken with round, sharply outlined brown spots

Infection and spread

• Naturally present in the soil
• Infection increases at lower soil temperatures post planting
• Infection spreads from seed tubers to underground stems

Possible confusion with

• Wireworm damage
• Scab