Cause Meloidogyne hapla, a nematode that also attacks many vegetable crops. Root-knot nematodes are sedentary endoparasites. Only second-stage juveniles (the infective stage) and, rarely, adult males are in soil.
Symptoms Areas of stunted plants in the field. Numerous knots or galls are on roots. Do not confuse them with the pinkish red interiors of nitrifying nodules found on roots of leguminous plants.
Sampling Before planting, take soil samples enough ahead of time to implement management procedures if needed. Fall sampling for planting the next spring is an excellent strategy. When sending samples for diagnosis, it is best to include roots as well as soil.
Cultural control Because the host range of this pest is so large, it is difficult to recommend a crop-rotation program. Cereal and grasses will reduce nematode populations.