The root-knot nematode is the most common nematode pest of soybeans in the southern states, and has more than 2,000 plant hosts. Four different species attack soybeans. All cause similar symptoms, including severe stunting and formation of galls or knots on the roots. Also, plants may appear to suffer nutrient deficiencies and may wilt during hot periods of the day. Nematode damage reduces yield and lowers quality.
Nematodes have a fairly simple life cycle.
Infected soil contains eggs and larvae. Larvae enter and feed within the roots of a host plant. There they develop into adults which lay eggs outside the root. Each egg mass may contain several hundred eggs. The life cycle requires only 3 to 4 weeks, so there may be several generations in one season.