Plant Diagnostic Database

Fusarium Wilt-Yellows  (Fusarium oxysporum)












Broccoli and other brassicas (cabbage, cauliflower, brussels sprouts, kohlrabi, kale); asparagus, celery, cucumber, pea, pepper, potato, radish, tomatoes, and dahlia.

Fusarium is a fungus that affects both seedlings and mature plants. It causes top growth to wilt, yellow and die. Lesions form at plant base or slightly below the soil line. Reddish-brown streaks appear in the root, stems and leaf petioles. The earliest symptom is the yellowing of old leaves, often on only one side of the plant. Fusarium is most prevalent on acid, sandy soils.
Life Cycle:
Fusarium overwinters on seeds and plant debris or in the soil. Spores germinate on susceptible roots through wounds, then spreads through xylem tissues. It is especially active in growing, succulent plants. The optimum temperature for spore production is 80°F.; spread of the disease slows at either extreme. Fusarium remains in the soil for several years, in some cases 10 years.               
Preventative: Biological:

Use a 5 - 7 year rotation. REMOVE AND DESTROY infected plants. Grow resistant varieties. In general, raise the pH to 6.5 - 7 if soil is acid. Use nitrate rather than ammonium nitrogen. Avoid poorly drained and cool soils.

Soak seeds (or, crowns, in the case of asparagus) in 1 part bleach to 4 parts water for 2 minutes, then rinse under running water for 1 minute.


Microbial Seed Treatments: Gliocladium virens(Soil Guard), Bacillus subtillus strains(Kodiak, Subtilex NG). 


 Return to Top

Go to Top