powdery scab

noun

Definition of powdery scab

: a disease of potato tubers caused by a fungus (Spongospora subterranea) and characterized by nodular discolored lesions which at maturity burst to expose a powdery mass of spores in circular pits surrounded by the lighter colored frayed remnants of the skin of the tuber

called also pock scab

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“Powdery scab.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/powdery%20scab. Accessed 3 Jun. 2020.

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