Root rot of carrot
nonsterile soil remained viable at 0°C and 3°C for 12 months, at 6°C for 6 months, and at 12°C for 2 months, indicating a capacity to overwinter in cold regions [...] or alternate hosts and transfer to annual crops. As far as is known, Daucus carota (carrot) is the only host plant of the fungus. How to prevent root rot [...] cause similar symptoms, which are collectively known as black spot diseases. When carrots are stored during winter, diseases on the carrot roots can continue