The lesions are, on average, less than half an inch in diameter and appear near harvest, but can grow as the carrot matures and grow larger on processing varieties of carrots. Low density hyphae are present in early formation of the lesions, but there is little to no presence of Pythium violae spores in the mature lesions making it difficult to diagnose in the field.
Carrot lesions typically measure less than half an inch in diameter and appear around harvest time; however, they can expand as the carrot ripens and grow larger on certain processing varieties. Initially, low-density fungal hyphae are present, whereas Pythium violae spores are rarely found in mature lesions, hindering accurate identification.