coronavirus

Scab

Fungal

Plant disease guide — symptoms, causes, treatment, and prevention.

symptoms

Symptoms

  • circleRaised, rough, corky patches on tubers, fruit, or root surfaces
  • circleDark, scabby lesions that may crack open
  • circleMostly cosmetic damage, though severe cases can affect storage quality
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Causes

Caused by various pathogens depending on host — for example, Streptomyces scabies (a soil-borne actinomycete) causes common potato scab, favored by dry conditions and alkaline soil during tuber formation.

healing

Treatment

There is no in-season cure; keep soil consistently moist during the susceptible tuber-forming stage to reduce severity, and peel affected produce, which remains edible under the skin.

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Prevention

Avoid liming soil before planting susceptible crops, rotate crops on a multi-year cycle, and choose scab-resistant varieties where available.