Endoparasitic nematodes in maize roots in the Western transvaal as related to soil texture and rainfall

Eight endoparasitic nematode species were recovered from 170 maize root samples in western Transvaal, Republic of South Africa. Pratylenchus zeae had the highest average population density (17,454/5 g roots), followed by P. neglectus (5,827/5 g roots), P. penetrans (5,617/5 g roots), P. brachyurus (3,060/5 g roots), Meloidogyne incognita plus M. javanica (301 juveniles/5 g roots), P. crenatus (130/5 g roots), and Rotylenchutus parvus (64/5 g roots). The 17 reasonably homogeneous farming areas (RHFA) surveyed could be ranked on the basis of the incidence of the prevalent nematode species. A positive relationship was found between the incidence of P. brachyurus and R. parvus and long-term average annual rainfall. The incidence of P. penetrans and the Meloidogyne spp. was positively related to a combination of sand percentage and long-term average annual rainfall.