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Screening for resistance to Maruca testulalis Geyer in cowpea (Vigna unguiculata L.) Walp

Published online by Cambridge University Press:  27 March 2009

J. N. Woolley
Affiliation:
Department of Applied Biology, University of Cambridge, Pembroke Street, Cambridge, England
A. M. Evans
Affiliation:
Department of Applied Biology, University of Cambridge, Pembroke Street, Cambridge, England

Summary

Screening methods were devised to select cowpea genotypes with resistance to yield loss oaused by larvae of Maruca testulalis (Lepidoptera, Pyralidae). More emphasis was placed on flower damage than on pod damage. One hundred and forty genotypes of wild and cultivated cowpeas and four of related Vigna speoies were screened in the first year; 25 of these were selected for rescreening in the second year. Resistance to flower damage was assessed by the ratio of number of pods under unsprayed conditions to number of pods under sprayed conditions and resistance to overall post-flowering damage by ratio of seed yield under unsprayed conditions to seed yield under sprayed conditions. The absolute numbers of pods and seed yields from unsprayed plots were also taken into account. Several genotypes of moderate resistance and one of high resistance were located among cultivars of different origins.

It is suggested that the empirical approach to the search for insect resistance, particularly the comparison of unprotected with protected yields, has great potential, especially for seriously damaged crops.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1979

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References

Akinfenwa, S. (1975). Bioeoological study of Maruca testulalis Geyer (Lepidoptera: Pyralidae) in the Zaria area of northern Nigeria. M.Sc. thesis, Department of Crop Protection, Ahmadu Bello University, Zaria, Nigeria.Google Scholar
Annual Report IITA (1975). International Institute of Tropical Agriculture, Ibadan, Nigeria, 1976.Google Scholar
Hamblin, J., Rowell, J. G. & Redden, R. (1976). Selection for mixed cropping. Euphytica 25, 97106.CrossRefGoogle Scholar
Hopkins, A. D. (1917). The host selection principle illustrated by mountain pine beetle Dendroctonus monticolae Hopk. (during discussions). Journal of Economic Entomology 10, 9293.Google Scholar
Ojehomon, O. O. (1969). Flowering, fruit production and abscission in cowpea Vigna unguiculata (L.) Walp. Journal of the West African Science Association 13, 227234.Google Scholar
Painter, R. H. (1951). Insect Resistance in Crop Plants. New York: Macmillan.CrossRefGoogle Scholar
Raheja, A. K. (1976). Assessment of losses caused by insect pests to cowpeas in northern Nigeria. Peat Articles and News Summaries 22, 229233.Google Scholar
Rawal, K. M. (1975). Natural hybridization among wild, weedy and cultivated Vigna unguiculata (L.) Walp. Euphytica 24, 699707.CrossRefGoogle Scholar
Siegel, S. (1956). Nonparametric Statistics. New York: McGraw-Hill.Google Scholar
Summerfield, R. J., Huxley, P. A. & Steele, W. M. (1974). Cowpea. Field Crop Abstracts 27, 301312.Google Scholar
Taylor, T. A. (1968). The bionomics of Maruca testulalis Gey. (Lepidoptera: Pyralidae), a major pest of cowpeas in Nigeria. Journal of the West African Science Association 12, 111129.Google Scholar