Fundamental and applied nematology vol:15 issue:6 pages:531-537
Nineteen plant-parasitic nematode species were recovered from 175 wheat fields in the seven major wheat-production areas of the Republic of South Africa. The predominant ectoparasites were Merlinius brevidens and Paratrichodorus minor. Both species occurred in almost 25 % of all soil samples. Scutellonema brachyurum, S. dreyeri, Paratylenchus minutus, Hoplolaimus pararobustus, Rotylenchus unisexus, R. mabelei and Xiphinema sp. were also found. The predominant endoparasites were Pratylenchus neglectus and P. thornei, which occurred in 28 and 18.9 %, respectively, of all root samples. Pratylenchus zeae, P. brachyurus, P. penetrans, P. crenatus, Rotylenchulus parvus, Ditylenchus destructor and Tylenchorhynchus sp. were also found. A Heterodera species, closely resembling Heterodera avenae, was recovered from six wheat fields. The seven wheat-producing areas surveyed could be ranked on the basis of the incidence of the plant-parasitic nematodes. The incidence of P. neglectus was negatively related to altitude. Positive relationships were found between the incidence of R. parvus and P. zeae and average annual rainfall and temperature. The incidence of R. parvus was also positively related to altitude and of P. zeae to percent sand.