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A Quantitative Assessment of Larval Infestation Level Required for Intensive Screening of Cowpea for Resistance to the Black Cowpea Moth, Cydia Ptychora (Meyrick) (Lepidoptera: Tortricidae)

  • T. I. Ofuya
  • A. E. Akingbohungbe
Research Article

Abstract

Assessment of the damage potential of Cydia ptychora (Meyrick) was carried out in Ife Brown cowpea at different levels of larval infestation and different pod growth phases. The results showed that C. ptychora caused significant shrivelling in pods of Ife Brown cowpea when infested with either one, two or three first-instar larvae per pod at either the young or mid-fill growth phases, relative to the corresponding controls. A significant reduction in seed yield was also recorded in plants subjected to an infestation level of either one, two or three first-instar larvae per pod at both mid-fill and mature pod growth phases. Thus, an infestation level of one first-instar larva per pod at either the mid-fill or mature pod growth phases would be adequate for intensive screening of cowpea varieties for resistance to C. ptychora, using Ife Brown as a standard for comparison.

Key Words

Larval infestation level screening cowpea resistance Cydia ptychora pod loss Ife Brown hypersensitivity 

Résumé

L’evaluation du point auquel Cydia ptychora (Meyrick) peut s’âbimer était effectueé sur Ife Brown cowpea aux nivéux differents de l’infestation lavaire et de phases différentes de la croissance de la cosse. Les résultats ont montré que C. ptychora a causé un dessèchement remarquable dan les cosses d’Ife Brown cowpea quand invests par un, deux, soit trois premières-étapes larves par cosse a soit la phase, jeure, soit le demi-état phase de développement, par rapport aux contrôles correspondants. Un rapetissement significatif en la production de grains etait aussi observé en plantes assujettiés à niveau d’infestation de sout un, deux, soit trois premières-étapes larves par cosse à la demi-état phase de développement et la phase mûre de la croissance de la cosse. Ainsi, un niveau d’infestation d’une première-étape larve par cosse à soit le demi-état phase soit la phase mûre de la croissance de la cosse serait suffisant pour un mise a l’abri intensif des variétés de cowpea pur régister a C. ptychora, utilisant Ife Brown comme un modèle de comparaison.

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References

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Copyright information

© ICIPE 1986

Authors and Affiliations

  • T. I. Ofuya
    • 1
  • A. E. Akingbohungbe
    • 1
  1. 1.Department of Plant ScienceUniversity of IfeIle-IfeNigeria

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