Plant-parasitic nematodes from vineyards in Jordan

Abstract

In Jordan, grapevines (Vitis spp.) are cultivated mainly in the hilly, northwestern regions under natural rainfall. Plantings in old and new irrigation schemes in the Jordan Valley (East Bank), Al-Hallabat and elsewhere are of less importance. Soil samples collected in 1983 from the rhizosphere of grapevines in Jordan contained several species of phytoparasitic nematodes (Table I). HeIicotylenchus pseudorobustus (Steiner) Golden was found in high numbers (> 1.070 nematodes/IOO ml soil) in some of the irrigated vineyards but apparently without causing decline. Other H eIicotylenchus spp. were less numerous and occurred solely in the drier, non-irrigated vineyards: Xiphinema pachtaicum (Tulaganov) Kirjanova was often found with these species. The occurrence of other species (Table I) was more erratic. In addition to the nematodes found during this investigation, Criconemella rustica (Micol.) Luc et Raski, Scutylenchus rugosus (Siddiqi) Siddiqi, Tylenchorhynchus clarus Allen, X. index Thorne et Allen and X. vuittenezi Luc, Lima, Wei scher et Flegg were previously reported from vineyards in Jordan (Bridge, 1978; Hashim, 1979). X. index is of particular importance in view of its role as vector of grapevine fanleaf virus; this virus infects grapevines in Jordan (Savino et al., 1975) but its association with the nematode vector in this country has not yet been established.