Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-28T04:46:07.576Z Has data issue: false hasContentIssue false

Cowpea plant architecture in relation to infestation and damage by the legume pod borer, Maruca testulalis Geyer (Lepidoptera: Pyralidae) — 2. Effect of pod angle

Published online by Cambridge University Press:  19 September 2011

S. Oghiakhe
Affiliation:
International Institute of Tropical Agriculture (IITA), Oyo Road, PMB 5320, Ibadan, Nigeria
L. E. N. Jackai
Affiliation:
International Institute of Tropical Agriculture (IITA), Oyo Road, PMB 5320, Ibadan, Nigeria
W. A. Makanjuola
Affiliation:
Department of Biological Sciences, University of Lagos, Akoka-Yaba, Lagos, Nigeria
Get access

Abstract

The effect of pod angle on the resistance of cowpea, Vigna unguiculata (L.) Walp. to the legume pod borer, Maruca testulalis Geyer, was investigated under field conditions at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, using two cowpea cultivars: IT82D-716 (susceptible to borer damage) and TVu 946 (resistant to borer damage). Three different pod angles were used In the study — a normal angle, a decreased angle and an increased angle. Negative and highly significant (P < 0.01) relationships were found between pod angle and per cent pod damage, as well as the seed damage Index In the two cowpea cultivars. Pods with wide angles (≥ 89°) were damaged on only one and rarely on both pods. Apart from biochemical and other bio-physical factors, selection and breeding for wide pod angle is suggested as a strategy for reducing M. testulalis damage to cowpea pods.

Résumé

L'effet de l'angle des gousses sur la résistance du niébé, Vigna unguiculata à la foreuse des gousses, Maruca testulalis a été étudié en champ à l'Institut international d'agriculture tropicale (IITA), Ibadan (Nigéria) sur deux cultivars de niébé: IT82D-716 (sensible) et TVu 946 (résistant). Trois angles différents des gousses ont été étudies: angle fermé, angle normal et angle ouvert.

Des relations négatives hautement significatives (P < 0.01) furent observées entre l'angle des gousses, le pourcentage de dégâts sur les gousses et l'indice de dégâts sur les graines chez les deux cultivars. Dans l'ensemble, pour les gousses à angle ouvert (>89°), M. testulalis a occasionné des dégâts sur une seule gousse par plant.

La sélection et l'amélioration du niébé pour l'obtention de gousses à angle ouvert ont été suggérées comme moyen de réduire les dégâts de M. testulalis sur les gousses de niébé.

Type
Research Articles
Copyright
Copyright © ICIPE 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Dabrowski, Z. T., Bungu, D. O. M. and Ochieng, R. S. (1983) Studies on the legume pod borer, Maruca testulalis (Geyer). 3. Methods used in cowpea screening for resistance. Insect Sci. Applic. 4, 141145.Google Scholar
Duncan, D. B. (1955) Multiple range and multiple F tests. Biometrics 11, 142.CrossRefGoogle Scholar
IITA (1988) IITA Annual Report and Research Highlights 1987/88 Ibadan, Nigeria.Google Scholar
Jackai, L. E. N. (1981) Relationship between cowpea crop phenology and field infestation by the legume pod borer, Maruca testulalis. Ann. Ent. Soc. Am. 74, 402408.CrossRefGoogle Scholar
Jackai, L. E. N. (1982) A field screening technique for resistance of cowpea (Vigna unguiculata) to the pod borer Maruca testulalis (Geyer) (Lepidoptera: Pyralidae). Bull. Entomol. Res. 72, 145156.CrossRefGoogle Scholar
Jackai, L. E. N. (1983) Efficacy of insecticide application at different times of day against the legume pod borer Maruca testulalis (Geyer) (Lepidoptera; Pyralidae), on cowpea in Nigeria. Prot. Ecol. 5, 245251.Google Scholar
Jackai, L. E. N. and Oghiakhe, S. (1989) Pod wall trichomes and resistance of two wild cowpea, Vigna vexillata, accessions to Maruca testulalis (Geyer) (Lepidoptera: Pyralidae) and Clavigralla tomentosicollis Stal (Hemiptera: Coreidae). Bull. Entomol. Res. 79, 595605.CrossRefGoogle Scholar
Jenkins, J. N. and Parrott, W. L. (1971) Effectiveness of Frego bract as a boll weevil resistance character in cotton. Crop Sci. 11, 739743.CrossRefGoogle Scholar
Oghiakhe, S. (1990) Resistance screening, biology and behaviour of Maruca testulalis Geyer (Lepidoptera: Pyralidae) on cowpea, Vigna unguiculata (L.) Walp. Ph.D. Thesis, University of Lagos, Lagos, Nigeria.Google Scholar
Oghiakhe, S., Jackai, L. E. N. and Makanjuola, W. A. (1991) Cowpea plant architecture in relation to infestation and damage by the legume pod borer, Maruca testulalis Geyer (Lepidoptera: Pyralidae), I. Effect of canopy structure and pod position. Insect Sci. Applic. 12, 193199.Google Scholar
Singh, S. R. (1978) Resistance to pests of cowpea in Nigeria. In Pests of Grain Legumes: Ecology and Control (Edited by Singh, S. R., van Emden, H. F. and Taylor, T. A.), pp. 267279. Academic Press, Inc. New York.Google Scholar
Singh, S. R. and Allen, D. J. (1980) Pests, diseases, resistance and protection in cowpeas. In Advances in Legume Science (Edited by Summerfield, R. J. and Bunting, A. H.), pp. 419443. Kew, London.Google Scholar
Stanton, W. R., Doughty, J., Orraca-Tetteh, R. and Steele, W. M. (1966) Grain Legumes in Africa. Rome, Italy, FAO.Google Scholar
Taylor, T. A. (1978) Maruca testulalis: an important pest of tropical grain legumes. In Pests of Grain Legumes: Ecology and Control (Edited by Singh, S. R., van Emden, H. F. and Taylor, T. A.), pp. 193200. Academic Press Inc., New York.Google Scholar
Usua, E. J. (1975) Studies in relation to Maruca testulalis. In Proc. IITA Collaborators' Meeting on Grain Legume Improvement, Ibadan, Nigeria, pp. 5254.Google Scholar