Importance and distribution of the main citrus plant parasitic nematodes in Morocco
A survey was conducted to determine the frequency of occurrence and population densities of plant-parasitic nematodes associated with citrus in six various regions of Morocco viz., Gharb, Loukkous, Moulouia, Haouz, Tadla et Souss-Massa. The citrus nematode Tylenchulus semipenetrans was found in all surveyed citrus orchards. The greatest infestation was found in the Loukkous region of Morocco on the valancia-late variety grafted on the sour-orange. Two species of root-lesion nematodes Pratylenchus coffeae and P. vulnus were identified in all prospected regions except Tadla region. Results indicate that the percentage of soil and root samples infested by Pratylenchus spp. ranged from 15 % in the Gharb to 66 % in the Souss-Massa region. The genus Xiphinema was found in all surveyed regions except the Haouz region. The highest percentage of infestation was found in the Loukkos region. Other plant-parasitic nematodes including: Tylenchus, Helicotylenchus, Paratylenchus and Tylenchorhynchus were identified on citrus.
Keywords : Survey, Citrus, Nematodes, Morocco