Cause Several fungi, primarily Fusarium spp. Stresses such as frequent cutting, winter injury, nutrient deficiencies, and wounding favor development of this disease. Fungal rots often are associated with insect injury caused principally by the clover root borer and clover root curculio. Damage increases as a stand ages. The disease can severely limit red clover production.
Symptoms Plants are pale green and stunted. They may wilt in hot weather. Roots and crowns have darkened, diseased tissue.
Cultural control
- Rotate out of legumes 3 to 4 years, ideally to grasses or grains.
- Control insects. See the PNW Insect Management Handbook for details.
- Maintain good plant vigor through high phosphorus and potassium levels, desirable soil pH, and recommended harvest schedules to avoid plant stress.