The fungus Fusarium infects crown, root, and fruit tissue of pumpkin. Symptoms have been observed on Long Island in fields where there is limited rotation, such as those used for u-pick, suggesting that it takes time for pathogen population to increase to a damaging level.
It is important to distinguish Fusarium crown rot from Phytophthora blight because conventional fungicides with targeted activity against Phytophthora are not effective against Fusarium. Plants wilting and dying from Fusarium crown rot are rotten at the crown area extending downward into the main root, internal tissue is yellow to orange while plant tissue infected by Phytophthora is collapsed, dark on the outside and inside, and occurs at the crown and further up on the vine with the roots often not affected. Fusarium crown rot tends to affect plants scattered throughout a field while Phytophthora blight is more often in areas where soil water drainage is poor. Both pathogens can survive in soil for years.