Author
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Timper, Patricia - Patty |
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DICKSON, DON - University Of Florida |
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STEENKAMP, SONIA - Grain Crops Institute Of South Africa |
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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 4/25/2017 Publication Date: N/A Citation: N/A Interpretive Summary: Groundnut is the common name for several leguminous plant species producing seed that mature underground, including Bambara groundnut, Hausa groundnut, and peanut. Hausa groundnut is cultivated as a food crop primarily in West Africa and there are no reports of nematodes affecting this plant. Bambara groundnut is an important legume in sub-Saharan Africa where it is grown primarily for human consumption. Domesticated peanut and Bambara groundnut will be the focus of this chapter. Potential peanut yield losses due to plant nematodes occur in every major peanut production region of the world. With losses estimated at 12%, it is clear that improved strategies are badly needed to reduce these losses. Root knot nematodes are the most important plant nematodes damaging peanut in most regions of the world but, in some regions, such as in West Africa, other species may be more serious. A number of nematodes, such as the testa nematode, the nematode causing Kalahasti malady, and the peanut pod nematode cause serious damage to peanut in isolated regions of Africa and Asia, but not in other regions of the world. The sting nematode is a pathogen of peanut in only certain regions of the USA. Nematode management has previously been based to a great extent on chemical control, particularly in industrialized countries. However, because of environmental and human safety concerns many nematicides have been withdrawn from the market. The potential for nematicides to contaminate water, as well as the cost of applying chemicals, has increased the urgency to seek safer and more economical chemicals and to develop other means of management. Resistant cultivars can be the best and most economical means of managing nematodes. Several commercial cultivars of peanut with resistance to root knot nematodes are available in the USA, which has reduced grower dependence on nematicides. Peanut cultivars with resistance to Kalahasti malady are also available in India, and cultivars with resistance to the peanut pod nematode are under development. Landraces of Bambara groundnut with resistance to root knot nematodes have also been identified. Expanded utilisation of cultural practices such as crop rotations, cover crops, trap crops, fallowing and flooding, organic amendments and other tactics that aid in reducing nematode damage is necessary for the maintenance of economical peanut production. More research is needed on understanding and predicting naturally suppressive soils, so as to aid producers in capitalising on this important and greatly underutilised tactic of nematode management. Efforts to prevent the spread of nematodes through sanitation and quarantine in extreme situations may contribute to future containment of nematode problems. Technical Abstract: Groundnut is the common name for several leguminous plant species producing seed that mature underground, including Bambara groundnut (Vigna subterranean), Hausa groundnut (Macrotyloma geocarpum), and peanut (Arachis spp.). Hausa groundnut is cultivated as a food crop primarily in West Africa and there are no reports of nematodes affecting this plant. Bambara groundnut is an important legume in sub-Saharan Africa where it is grown primarily for human consumption. Domesticated peanut (Arachis hypogaea) and Bambara groundnut will be the focus of this chapter. Potential peanut yield losses due to plant nematodes occur in every major peanut production region of the world. With losses estimated at 12%, it is clear that improved strategies are badly needed to reduce these losses. Meloidogyne spp. are the most important plant nematodes damaging peanut in most regions of the world but, in some regions, such as in West Africa, other species may be more serious. A number of nematodes, such as Aphelenchoides arachidis, Aphasmatylenchus straturatus, Scutellonema. cavenessi, Tylenchorhynchus brevilineatus and Ditylenchus africanus cause serious damage to peanut in isolated regions of Africa and Asia, but not in other regions of the world. B. longicaudatus is a pathogen of peanut in only certain regions of the USA. Nematode management has previously been based to a great extent on chemical control, particularly in industrialized countries. However, because of environmental and human safety concerns many nematicides have been withdrawn from the market. The potential for nematicides to contaminate water, as well as the cost of applying chemicals, has increased the urgency to seek safer and more economical chemicals and to develop other means of management. Resistant cultivars can be the best and most economical means of managing nematodes. Several commercial cultivars of peanut with resistance to Meloidogyne spp. are available in the USA, which has reduced grower dependence on nematicides. Peanut cultivars with resistance to T. brevilineatus are also available in India, and cultivars with resistance to D. africanus are under development. Landraces of Bambara groundnut with resistance to Meloidogyne spp. have also been identified. Expanded utilisation of cultural practices such as crop rotations, cover crops, trap crops, fallowing and flooding, organic amendments and other tactics that aid in reducing nematode damage is necessary for the maintenance of economical peanut production. More research is needed on understanding and predicting naturally suppressive soils, so as to aid producers in capitalising on this important and greatly underutilised tactic of nematode management. Efforts to prevent the spread of nematodes through sanitation and quarantine in extreme situations may contribute to future containment of nematode problems. |
