Fusarium oxysporum proliferatum and Fusarium oxysporum infection of commercial asparagus spears originates from infected crowns in the field

It has been established that marketable asparagus spears are infected with Fusarium species. In the desert asparagus growing areas of Mexico and Southern California have an average spear infection ranges between 15 to 98%. Of these infected spears, 78% contained F. proliferatum, and 22% F. oxysporum. To determine the infection source, a declining field was randomly sampled by removing pieces of crown and emerging spears. Results showed that 62% of the crowns were infected with F. proliferatum and 37% with F. oxysporum. Sixty-two percent of spears removed from the same crowns were infected by F. proliferatum and 38% with F. oxysporum. Results of this study suggests that the source of spears infection by F. proliferatum and F. oxysporum is from infected crowns and not from normal postharvest operations.