A reddish discoloration extending from the roots to the lower nodes is evident on the stems of wilted plants. Dead plants may occur as either a few in a row or as patches in low areas of fields. Reduced tillage and monoculture of soybeans may increase the damage due to the disease. Control of Phytophthora root rot requires a combination of soybean variety selection and good soil management. Soybean varieties with resistance or tolerance to Phytophthora root rot are available.
Some varieties have both resistance and tolerance.
Resistance in any one soybean variety is effective against some but not all of the races. If this occurs, use a tolerant variety. Some disease develops in these varieties when grown in infested soils, regardless of which races of Phytophthora are present. However yields of tolerant varieties usually are not seriously reduced by the disease. Any soil management practice which reduces soil compaction or waterlogging will decrease the incidence of Phytophthora root rot.