Extension > Garden > Diagnose a problem > What's wrong with my plant? > Vegetable > Potato > Deformed tuber
Potato > Tuber > Deformed tuber
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Black Scurf/Rhizoctonia Canker
Rhizoctonia solani
- Tuber production is low, tubers may be small and deformed
- Underground stems and roots have brown, sunken dry spots
- Small hard black spots stick to the skin of the tuber like dirt that won't wash off
- In severe cases, small green tubers form on the stem above ground
- Stem has a white to gray flaky growth just above the soil line.
- Delayed or not emergence, have few stems, and poor growth
- Most problematic in cool wet soils
- More information on Black Scurf/Rhizoctonia Canker
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Corky Ring Spot
Tobacco Rattle Virus
- Potato tubers can be cracked and malformed if infections comes in early
- Brown rings and arcs form on the skin and in the flesh of tubers
- Leaves may have no symptoms or have yellow rings, spots and arcs
- Stems may be mottled green and yellow
- More information on Corky Ring Spot
