As the season progresses and soil heats up and is dry in the upper layers, nematodes may burrow deep into the soils and can sometimes be found at depths of 30 to 40 inches. Thus, it is important for producers to sample early in the season even if corn has already been planted. These samples will provide information for the next corn crop. The use of a soil treatment such as Counter CR or Mocap at planting can provide the early season protection needed for establishing a healthy root system on corn. Thus, producers who wish to treat soils for nematodes should use a band application and not an in-furrow to maximize nematode control.
Crop rotation can also be effective against some corn nematodes, especially the needle nematode.
The needle nematode is the most damaging of the corn nematodes and has a host range primarily limited to grass crops. Rotation with soybeans for a single year can effectively reduce needle nematode populations. Research conducted by the late Dr. Richard Malek indicates that the needle nematode can feed and damage many grasses, including corn and small grains, but can also parasitize potato plants. Thus, soybeans would be the most effective of the alternate crops because there was no evidence that this crop is affected by the needle nematode. Control of grasses in the field, both in the current year and in the rotation crop, is important.