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