Fusarium builds up to extremely high levels during the long period of asparagus culture in the field, and survives many years in that soil even after the crop is removed. Use treated seed. Untreated seed should be disinfested with 1 part sodium hypochlorite bleach in 5 parts water for two hours. Rinse seed in fresh water and dry before planting. Use only vigorous, one year old crowns and encourage proper handling procedures for transplanting.
Weak crowns are highly susceptible to infection.
Minimize stress in young and established plantings. Use resistant varieties. At present, no varieties recommended in Ontario are resistant. However, lines and varieties being developed in the University of Guelph breeding programme are being screened for Fusarium resistance. Some members of the onion family, such as cooking onions and chives, are also susceptible.