NAME OF THE ORGANISM: Meloidogyne incognita (MELGIN)

Evaluation continues

Remarks: M. incognita is only mentioned in PM4/017(3) olive trees and rootstocks, not in the PM4 certification schemes available for all Prunus spp. These schemes post-date the first mentioning of M. incognita in Europe. However, PM 4 certification schemes for Prunus spp. require that the higher grades are produced in sterilized growing medium.
The assessment performed covers the given host species as well as interspecific hybrids with other Prunus species.

Candidate

Main transmission modes (in addition to plants for planting) is through soil (EPPO, 2022; PM4/017)
Meloidogyne arenaria, M. javanica and M. incognita are the most common species in warmer conditions of southern Europe, but also in glasshouses in northern Europe (Wesemael et al., 2011).
Meloidogyne incognita is probably the most widely distributed and economically important species of plant parasitic nematode in tropical and subtropical regions. Two-thirds of the root-knot nematode samples obtained from a number of tropical countries were of M. incognita (Sasser, 1979). In India alone, 232 plant genera have been reported as hosts to M. incognita (Krishnappa, 1985) and worldwide the species is a parasite of a wide range of crop plants (cited from CABI, 2021).
Eggs and juveniles can travel with soil, so anything which has soil attached is a potential pathway including agricultural equipment and containers, tools, vehicle tires, and workers clothing or boots (CABI, 2021). The nematodes can also be transported by water; down river flooded fields can become infected (Clavero-Camacho et al., 2024).
Meloidogyne spp. are not transmitted with seeds (in Wesemael et al., 2011).

Yes

Although Meloidogyne is considered worldwide as the most important genus of plant-parasitic nematodes, information in the scientific literature on the economic impact of root-knot nematodes in Europe is scarce (Wesemael et al., 2011).
The four major Meloidogyne species, M. incognita, M. javanica, M. arenaria, and M. hapla can cause economic damage to stone fruits (Marull et al., 1992) and yield losses (McKenry, 2004) in different parts of the world. Root-knot nematodes cause a 15% loss in vigour and yield of Prunus crops (nurseries and orchards) on a worldwide basis. The economic importance of Meloidogyne spp. to stone fruits was shown with the use of nematicides and rootstocks with nematode resistance. Sharpe et al. (1993) showed that pre-plant fumigation with methyl bromide to control Meloidogyne spp. in peaches increased the cumulative yield over 3 seasons by 2535Kg per hectare. Nematicides have been used to increase yield on many different crops.
In Mediterranean and warm temperate climates, the perennial crops most affected by root-knot nematode species include Prunus spp. and, to a lesser extent fig (Ficus carica) (Saucet et al., 2016).

Medium

No

Candidate

For most Prunus spp., root-stocks resistant against root knot nematodes are available (Saucet et al., 2016); however, the Fruit SEWG considered that these rootstocks are only rarely used. The economic impact is rated as Medium in absence of resistant rootstocks.

Candidate

Rootstocks with a wide resistance spectrum for Meloidogyne spp. have been developed using the Myrobalan plum, P. cerasifera, as a parental (Saucet et al., 2016).
Use of clean soil: The propagation material is kept either in containers of sterilized growing medium or in soil that has been tested and found free from Xiphinema diversicaudatum (see EPPO Standard PM4/35), Meloidogyne arenaria, M. incognita, M. javanica, Pratylenchus vulnus and Verticillium dahlia (EPPO 2022)
Woody crops are generally grown in long-term specialized production systems that remain in place for decades. It is not possible, therefore, to control polyphagous root-knot nematode species by crop rotation (Saucet et al., 2016).

Candidate