Two Pythium species are mostly responsible for forking and cavity spot of carrots in Australia. In most cases, P. sulcatum cause the symptoms.
While some general rules apply, especially the need for managing soil moisture, pH, soil calcium and crop maturity; carrot producers should find their own optimum combination of additional management strategies that fit their production systems and growing conditions.
Read this useful fact sheet to find out more about what causes cavity spot and forking in carrots, as well factors affecting cavity spot development and management approaches.