Cause Several Fusarium sp., including F. avenaceum, F. oxysporum, and F. solani. These fungi survive in infected plant parts as well as be soilborne for many years.
Symptoms Mid- to late-season bronzing, yellowing and reddish to purple coloring in the top leaves. Leaf margins turn up slightly. Stems usually remain a dark, dull green after leaves wilt. Vascular tissue of stems, roots, and leaf petioles turns brown with some brownish flecking of the pith. Symptoms are similar to Verticillium wilt. Tubers show a sunken brownish discoloration at the stem end.
Cultural control
- Plant certified pathogen-free seed.
- Use long rotations.
- Disinfect storage houses and equipment.
Biological control
- Amplitude at 3.2 to 4.8 fl oz/100 lb seed pieces, 6 to 8 fl oz per 1,000 ft row as an in-furrow treatment, or 3 to 4 quarts/A as a chemigation treatment on 14- to 21-day intervals. Preharvest interval is 0 days. 4-hr reentry. O
- Heads Up at 0.035 oz/34 fl oz water/220 to 582 lb seed pieces will stimulates pest suppression system of plants. Efficacy unknown. 12-hr reentry. O
- Regalia at 1 to 2 quarts/A as an in-furrow treatment. Does not benefit from the addition of an adjuvant.4-hr reentry. O
- Stargus at 6 to 8 fl oz per 1,000 ft row as an in-furrow treatment, 3 to 4 quarts/A as a soil drench on 10- to 14-day intervals, or 3 to 4 quarts/A as a chemigation drip treatment on 14- to 21-day intervals. Preharvest interval is 0 days. 4-hr reentry. O