Plant-Parasitic Nematodes Associated with Garlic in Yemen

Abstract

A survey was undertaken to determine the frequency and abundance ofplant-parasitic nematodes associated with garlic (Allium sativum L.) in major garlicproduction governorates in Yemen. Twenty nematode genera were found inassociation with garlic in Sana'a, Ibb and Hadramout governorates of whichAntarctenchus, Aphelenchoides, Aphelenchus, Basiria, Boleodorus, Ditylenchus,Helicotylenchus, Heterodera, Hoplolaimus, Meloidogyne, Microposthonia,Nothanguina, Pratylenchus, Rotylenchulus, Rotylenchus, Scutellonema,Tetylenchus, Tylenchorhynchus, Tylenchus and Zygotylenchus. All nematodegenera except Aphelenchus, Helicotylenchus, Meloidogyne and Tylenchorhynchushave been reported for the first time on garlic in Yemen. The most prevalent plantnematode genera associated with garlic cultivars in all surveyed districts wereAphelenchus, Ditylenchus, Pratylenchus, Tylenchorhynchus and Tylenchus. Thelargest number of nematode genera was recorded in Sana'a governorate (19genera) compared to Ibb (14 genera) and Hadramout (12 genera). Antarctenchus,Hoplolaimus, Microposthonia, Nothanguina, Scutellonema and Zygotylenchusgenera were only found in Sana'a governorate, while Heterodera was recorded onlyin Ibb governorate. The most serious pests on garlic, stem and bulb nematode(Ditylenchus) exhibited the highest average population density of 4214nematodes/250gm soil with frequency of occurrence 49%. Therefore, effects ofnematode damage on growth, vigor and yield of garlic need further investigation.