They can cause substantial damage to plants by feeding on the roots, thus hampering or even destroying the plant's ability to absorb nutrients and water. Nematodes can also transmit other plant pathogens or increase the susceptibility of plants to diseases. Nematode losses are not restricted to commercial growers. The home garden, landscape ornamentals, lawns, and fruit trees can also be severely damaged. As a result of the root damage, plants show symptoms of reduced growth, nutrient deficiency symptoms such as yellowing of foliage, excessive wilting in hot or dry weather, and reduced yields.
Damage often occurs in randomly spaced patches in a field or yard.
The only way to positively identify the type and extent of a suspected nematode problem is by soil sampling and a laboratory assay. Ideally, this should be done before a crop is planted so the grower can choose a resistant variety, a non-host crop, or apply a nematicide if the assay results indicate a nematode problem. The optimum time to sample crops is near harvest. Lawns, trees, and shrubs may be sampled any time of the year. We recommend annual sampling for nematodes.