Cause Fusarium spp., Phytophthora megasperma, Pythium spp., Rhizoctonia solani, and other fungi. These microorganisms can survive in soil for many years. Wind and water can move infested soil and plant debris. The disease is favored by extremes in soil moisture (too dry or too wet). Anything, which impedes root growth such as cold or compacted soils also favors the disease.
Symptoms Above ground portions of the plant wilt, and plants may die. Lateral roots are absent or entirely decayed. Tap roots are entirely decayed or show large, dark lesions along their entire length. Symptomatic plants are found in wet areas of the field.
Cultural control
- Plant only on well-drained soil that has a minimum of low areas where water can accumulate.
- Avoid excessive irrigation.
- Practice a 3-year rotation with nonsusceptible crops.
Biological control
- Stargus at 6 to 8 fl oz per 1,000 ft row as an in-furrow treatment. Preharvest interval is 0 days. 4-hr reentry. O