Plant-parasitic nematodes on stone fruits and citrus in Lebanon

Abstract EN

This study aimed to determine the occurrence, distribution of plant parasitic nematodes on stone fruits in Lebanon and to determine the effect of plant extracts on the mortality of several nematode species.

A total of 308 soil samples were collected from five different crops.

Almost all surveyed areas showed infection with nematodes.

The soil infestation rate with nematodes in collected soil samples from all 10 surveyed crops ranged from 66.6 to 100%.

Eighteen out of 308 soil samples were free of nematodes (5.8%).

All the collected soil samples from nectarine and plum orchards were infested with nematodes (100%), followed by citrus (97.6%), apple (88.7%), pear and quince (85.7%), and cherry (81.4%).

The lowest infection (66.6%) was detected on almond and apricot.

The level of infestation varied from one area to another and ranged between 0.1 and 28 nematodes per 1 g of soil, with the highest number obtained on cherry.

Several genera were identified based on morphological characters including: root-knot nematodes (Meloidogyne spp.), Tylenchulus, Xiphinema, Rotylenchus, Pratylenchus, and Longidorus.

Tylenchulus and Radopholus spp.

were the most common on citrus trees, whereas Pratylechus and Meloidogyne spp.

were detected almost in all the samples collected from all the crops.

Six chopped aromatic plants were tested in pot experiments to control nematodes population densities.

The results revealed that carbofuran (nematicide) was the most effective (88.48%) in comparison to the plant materials.

Allium sativum gave the highest control (76.52%) followed by Tageta patula (72.0%), Cucurbita maxima (71.84%) and Inula viscosa (63.96%).

Origanum syriacum (55.04%) and Thymus (53.72%) were less effective in comparison to the rest of tested plant materials.