Crop Science and Agriculture

Updates on the phytonematodes that parasitize maize (staple food and important livestock feed source), groundnut and soybean (important sources of protein and oil) were done for South African production areas. Such interventions focused on the abundance, diversity and identity of nematode pests. Root and soil samples were obtained from 78 commercial maize fields (irrigation and rain-fed); soybean surveys were done for conventional and genetically modifi ed, glyphosate-resistant crops (17 fi elds in total) and groundnut samples were obtained for diagnostic and research purposes. Phytonematodes were extracted, counted and morphologically identifi ed from soil and plant samples using standard protocols. Molecular species identification was also done, including various DNA sequence protocols and SCAR-PCR (specifi cally for Meloidogyne spp.). Meloidogyne and Pratylenchus were identifi ed as the predominant genera infecting maize and soybean. Meloidogyne incognita, M. javanica, M. arenaria were predominant for maize and M. incognita and M. javanica for soybean. Meloidogyne enterolobii was found also in one maize fi eld and is a fi rst report for local maize despite the crop being listed in international literature as a non- or poor host of this species. Pratylenchus zeae and P. brachyurus dominated in samples from maize and soybean crops, with P. fl akkensis, P. scribneri and P. vulnus being fi rst reports for soybean in South Africa. Regarding groundnut, Robustodorus arachidis was identifi ed for the first time worldwide infecting the crop. Knowledge generated for these crops is important and useful and can be used for planning and deploying management strategies to produce such and other rotation crops, where economically important phytonematodes pose problems to producers and related industries.