In a nematode survey of eight commonly grown root and tuber crops (cassava, sweet potato, potato, yam, tannia,
taro, carrot and turmeric) from 430 fields in Uganda, 69 species of plant-parasitic nematodes representing 28 genera were extracted from soil and roots. About twice as many nematode species were recovered from soil (64) as
from roots (36), while 32 species were found only in soil and four species only in roots, usually in mb(ed populations.
Meloidogyne spp. (root-knot nematodes) were the most frequenlly recovered across crops, with the major species
(M. arenaria, M. hapla, M. incognita and M. javanica) observed on cassava. Some nematodes were recovered only
from specific crops, Sweet potato yielded the greatest diversity of species (55 species in 25 genera), followed by
cassava (40 species in 19 genera) and yam, which was sampled principally in the northern and eastern regions of
Uganda (39 species in 14 genera). Results of the study provide baseline information lor more detailed local population studies and nematode pathogenicity evaluations on important root and tuber crops,