STUDIES ON NEMATODES IN NORTH SINAI

Abstract

The purpose of the present work was mainly aiming to throw light on plant parasitic• nematodes infecting peach , olive and citrus which are considered the most important economically growing fh1it crops in North Sinai Governorate . The work was• also extended to determine seasonal population dynamics ofthe most predominant species infecting these crops . Moreover , nematicidal efficiency of eight wild plant species and olive mill waste water in comparison with the •nematicide oxamyl against the root-knot nematode Meloidogyne incognita was also highlighted in the present study . The obtained results could -, be swru:rialized as• follows :

1- Eight genera of plant parasitic nematodes were found in association with peach trees grown in nine localities of North Sinai Governorate . These genera were Criconemoides , He/icotylenchus, Hoplolaimus, Longidoms, Meloidogyne Paratylenchus , Tylenchorhynchus and Xiphinema . The most frequently genera in the total collected samples wereMeloidogyne spp. , Longidorus spp. , Helicotylenchus spp. and Tylenchorhynchus spp.. Their percentages of frequency occunence were 65.29 , 63.52, 52.35 and 42.94% respectively. On the other hand , the• highest values of population density were detected with the genera Helicotylenchus , Meloidogyne , Tylenchorhynchus and Hop/olaimus . Their population density per 250 gm.soil were 95 , 84 , 78 and 46 nematodes , respectively . The identified genera varied in their frequency of occurrence and population . density from OIe locality to another . Most of the identified genera were found with different positions . when they were arranged descendingly according to frequency of occuncnce and population density . Therefore they can be applied together as prominence value Generally , the genera Helicotylenchus, Me/oidogyne and Tylenchorhynchus were found with high prominence values while other genera were found with median or low prominence values .