Cavity spot
Pythium sulcatum

Description
Cavity spot is characterized by elliptical to irregularly shaped depressed lesions oriented across the mature carrot taproots. Individual lesions are usually less than 0.5 inch (1.3 cm) in diameter, but can be much larger, especially on processing varieties. Infections occur anywhere along the taproot, but lesions tend to be more abundant on the upper third of the root and are often found where lateral roots emerge from the taproot. Lesions begin as pinpoint sunken spots and generally enlarge as roots mature.