Lesions also can develop on pods in contact with the moist soil surface, and cause pod rotting and seed discoloration. Pythium Pythium problems usually are scattered throughout a field, thus the affected sectors do not form a pattern. The pathogen may affect seeds, seedlings, young and older plants, and pods. The fungus can cause seed decay and seedling death. Initial root symptoms appear as elongated water-soaked areas on the hypocotyl and roots.
Symptoms usually occur within one to three weeks after planting.
Initially, the infected outer tissue of the stem becomes slimy and can easily slip from the central core at this stage. However, eventually it dries out, becomes sunken, and turns tan to brown in color. Severely infected plants commonly wilt and die. The pathogen can extensively prune roots, reduce overall plant growth, and destroy much of the hypocotyl and main root system. A water-soaked region on infected seedlings or plants may extend several inches above the soil line with little, if any, visible evidence of the fungus.