Nematode Pests of Leguminous and Oilseed Crops
Sunflower ranks first among the legume and oilseed crops produced in South Africa, followed by soybean. The production of Bambara groundnut, cowpea, dry bean, groundnut and lupin is practised on a much smaller scale. The omnipresence of economically important plant parasitic nematodes poses a threat to the sustainable production and expansion of leguminous and oilseed crops, with Meloidogyne and Pratylenchus spp. as generally the most damaging nematode pests. Ditylenchus africanus (indigenous to Southern Africa) is the predominant nematode pest of groundnut. The discovery of Aphelenchoides arachidis individuals in groundnut pods also poses a threat to producers. In this chapter, symptoms of damage inflicted by particular plant parasitic nematodes on leguminous and oilseed crops are described, as are the management strategies available to local producers. These typically include the use of chemical control, crop rotation and to a lesser extent host plant resistance. Of particular interest are discussions on root knot nematode resistance breeding in soybean and the development of molecular markers to expedite the breeding process. The same applies for D. africanus and groundnut. Although nematode research focused mainly on groundnut and soybean, information for Bambara groundnut, cowpea, dry bean, lupin and sunflower is also presented.