Cavity spot—Pythium violae
Cavity spot is characterized by elliptical to irregularly shaped depressed lesions oriented across the
mature carrot tap roots. Individual lesions are usually less than 0.5 inch in diameter, but can be much
larger, especially on processing varieties. Infections can occur anywhere along the tap root, but lesions
tend to be more abundant on the upper third of the root. Lesions begin as pinpoint, sunken spots and generally
enlarge as roots mature.
Identification
SolutionsThe fungus that causes cavity spot is favored by low soil temperatures. Practice 3-year crop rotations
with nonhosts of the disease such as tomato, watermelon, corn, and potato. Do not overirrigate. Harvest
carrots soon after they mature because older carrots are more susceptible to infection. All carrot varieties
are susceptible.
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Cavity
spot on carrots
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