Almost all plant species are parasitized by one or more nematode species. Figure 1 shows how plant-parasitic nematodes use their oral spear or stylet to pierce root cells and extract nutrients. A root under assault by the two main classes of plant-parasitic nematode. You might think that a pest this damaging should be easy to identify. However, although some nematodes do cause distinctive damage to root systems, most do not.
Growers frequently attribute nematode-related growth reductions to nutrient or water deficiencies.
These diagnoses are partially correct. Roots damaged by nematodes often cannot adequately absorb nutrients and water. In addition to feeding on roots, nematodes also increase the likelihood that plants will be infected by disease-causing bacteria, fungi, and viruses. Even disease-resistant varieties are at risk. The area around the stylet puncture is particularly vulnerable.