الفهرس 
Ecological studiesOnly 14 pages are availabe for public view
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Abstract
This study was conducted under field conditions in a Valencia orange orchard planted in sandy soil and another planted in clay soil, where root and soil samples were collected monthly for two consecutive years for the purpose of conducting environmental studies on nematodes parasitic on orange trees.
After analyzing the results of this study, several methods of control were evaluated, using a chemical pesticide or biological control, using fungi and bacteria, or conducting chemical control, then biological control and vice versa, and studying the resulting effect on orange seedlings.
The obtained results showed that the most important nematodes parasitizing on summer orange trees are citrus nematodes Tylenchulus semipenetrans and lesion nematode , Paratylenchus spp and root-knot nematode, Meloidogyne spp and dagger nematode, Xiphinema americanum .
The treatment of oxamyl + Mycorrhizae recorded the greatest effect in reducing the rate of infestation, as the number of larvae after 4 weeks of application reached about 672 larvae per 100 cm3 of soil, which is the lowest number of larvae compared to other pesticides with a percentage of 48.3% of the total number of larvae, which reached at this period 1300 larvae per 100 cm3 of soil.
The seedlings treated with oxamyl + Mycorrhizae recorded the lowest roots containing the number of larvae, reaching 10 larvae per gram per root, with a percentage of 63.2% of the number of larvae present in one gram of untreated plant roots.