Fusarium Wilt
Fusarium oxysporum (various formae speciales)
Overview
A devastating soil-borne fungal disease that invades plant roots and colonizes the vascular system, blocking water transport and causing progressive wilting and death. The pathogen can persist in soil for decades.
Symptoms
One-sided wilting of leaves or branches (often starting on one side of the plant). Yellowing of lower leaves progressing upward. Brown discoloration of vascular tissue visible when stems are cut. Stunting and eventual plant death.
Environmental Conditions
Hot
Prevention
Plant resistant varieties (the most effective strategy). Rotate crops on a 5+ year cycle. Maintain soil pH above 6.5. Use clean transplants and tools. Solarize soil in warm climates.
Management
No effective chemical cure once plants are infected. Remove and destroy infected plants. Do not compost. Solarize soil. Add beneficial microbes (Trichoderma, mycorrhizae). Grafting onto resistant rootstocks.