SURVEY OF PLANT PARASITIC NEMATODES GENERA ASSOCIATED WITH SUGAR BEET PLANTATIONS IN DAKAHLIA GOVERNORATE

A survey of plant parasitic nematodes genera associated with the rhizosphere of seven sugarbeet cvs. kawemira, monte-bionco, deprez-poly n, sultan, nejama, athos-poly and farida grown at five counties of dakhlia governorate (egypt) was carried out during the sugar beet growing season 2007/2008/2009. nine nematode genera were recorded in the surveyed sugar beet fields. based on their frequency of occurrence , these genera can be arranged in ascending order as follows : meloidogyne (j2) (22.6%) , trichodorus (19.8%), hirschmanniella (13.4%), helicotylenchus (10.4%), tylenchus (6.5%), pratylenchus (4.7%), dorylaimus (3.4%), rotylenchulus (1.7%), and tylenchorhynchus (1.3%). among the seven true nematode genera recorded, meloidogyne and trichodorus seemed to be the major pest of sugar beet plantations in this work. meanwhile , clay soil with 413 out of 700 soil samples examined encountered the highest number of nematode genera (7) followed by loamy (5) and clay loam (4) .