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Symptoms: Brown, reddish brown, grey or black sunken eroded lesions form on the roots or lower stem of infected plants. Plants are often stunted and lower leaves turn yellow. Photo by Plant Disease Clinic |
Root rot of bean may be caused by several fungi and it is often difficult to determine the causal agent without laboratory analysis. |
Symptoms: Brown, reddish brown, grey or black sunken eroded lesions form on the roots or lower stem of infected plants. Plants are often stunted and lower leaves turn yellow. Photo by Plant Disease Clinic |
| Causal organism: | Rhizoctonia, Pythium, Aphanomyces, Fusarium, Ascochyta, Thielaviopsis |
| Over wintering: | Soil, plant residue, infected seed (Ascochyta) |
| Months of infection: | May-August |
| Method of dispersal: | Infected seed, spread of infested soil and plant debris |
| Infection point: | Infection occurs through wounds and natural openings in the roots. |
| Control: | Avoid excessive soil moisture and soil compaction, rotate crops, plant disease-free seeds, avoid moving soil in which diseased plants have grown to new areas. Delay planting until soil is above 65 F. |
| Labeled fungicides: | Not economically feasible |
| Comments: | Root rots are most common in heavy, wet, compacted soils. |
| Additional Information | Back to Bean Diseases |
