Cause Pythium spp. and Fusarium spp. can cause root rot and seedling blight known as damping-off. These soilborne fungi and fungus-like microorganisms can persist indefinitely in soil or plant debris. Pythium is favored by wet soils.
Symptoms Seeds may rot prior to germination ("seed decay"), or the seedling may become infected prior to emergence ("pre-emergence damping-off") or soon after emergence ("post-emergence damping-off"). In the latter cases, the stem of the seedling becomes infected and tissues become discolored and soft, resulting in the seedling toppling over after it has emerged from the ground. Root and lower stem infections may occur later in the plant development, resulting in brown and discolored roots, absence of roots, and stunted, unthrifty plants with reddish foliage.
Cultural control
- Plant seed in warm (over 55°F), moist but not wet soil.
- Tillage practices that decrease plant residues on the soil surface may result in less disease.
Chemical control
- Seed treatment.
- STartUP FLUDI (Group 12) at 0.08 to 0.16 fl oz/100 lb seed plus a dye can help with seed rot and damping off caused by Fusarium spp. 12-hr reentry.
Biological control
- Bexfond at 7 to 14 fl oz/A. O
- Prestop WG. 4-hr reentry. O
- Stargus at 3 to 4 quarts/A as a soil drench on 10- to 21-day intervals. Preharvest interval is 0 days. 4-hr reentry. O