Survey of plant parasitic nematode associated with spinach, Swiss chard and table beet in north Egypt.
A nematode survey was conducted in Alexandria, El-Behera, El-Gharbia, El-Monufia and Kafr El-Sheikh governorates in northern Egypt during the 2017 - 2019 cropping seasons to study the occurrence, population density and host association of plant parasitic nematodes associated with spinach, Swiss chard and table beet. A total of 854 soil and root samples were collected from the rhizosphere of the surveyed vegetable crops. The surveyed governorates and their respective numbers of soil samples were as follows: Alexandria 230, El-Behera 206, El-Gharbia 138, El-Monufia 211 and Kafr El-Sheikh 69 samples. Plant parasitic nematodes in the collected soil and root samples were extracted, identified, and counted under the compound light microscope. The collected soil and root samples contained mixed populations of 15 genera and 18 species of phytoparasitic nematodes that are reported for the first time on spinach, Swiss chard and table beet in Egypt. The root-knot nematode(Meloidogyne spp.) with 37 - 67 frequency of occurrence (FO) were the most frequently encountered group of nematodes, followed by spiral (Helicotylenchus sp.), cyst (Heterodera sp.), lesion (Pratylenchus sp.) and stunt (Tylenchorhynchus sp.) with 15 - 61 FO. The genera Criconema, Criconemella and Tylenchus were quite common. However, the other genera (Ditylenchus, Hoplolaimus, Psilenchus, Rotylenchulus, Rotylenchus, Trichodorus, and Xiphinema) were less common. The nematode species Meloidogyne arenaria, M. incognita, M. javanica, Heterodera schachtii and H. trifolii were identified on spinach, Swiss chard and table beet roots. The occurrence of the cyst nematodes H. schachtii and H. trifolii on spinach, Swiss chard and table beet are new records in Egypt. Also, survey results revealed new host plant records for most of the identified nematode genera and species in Egypt.