Nematodes

Plant-parasitic nematodes (PPNs) represent an important constraint for plant production worldwide. They are widely distributed around the world and are able to parasitize every plant species. Furthermore, the current restrictions on the use of chemical nematicides have increased the problems caused by PPNs, irrespective of the production system. Intensive vegetable production under protected cultivation is the system most vulnerable to PPN, especially to root-knot nematodes. Despite the high frequency of occurrence of root-knot nematodes, other PPN species occur in nematode communities, whose structure and composition are influenced by the plant species, the environmental conditions, the agronomical practices and the level of specificity of the control methods used to manage them. Integrated nematode management strategies must therefore be designed using a holistic approach that considers all the interactions between PPN species in the nematode communities, plant species and biotic and abiotic environmental conditions. The use of specific management tactics against a key PPN species only leads to changes of this species for others without solving the problem. Long-term studies that consider all of these complex relationships are therefore needed to manage the pathogenicity of the whole PPN community.