Global Advanced Research Journal of Agricultural Science (GARJAS) ISSN: 2315-5094
November 2014 Vol. 3(11): pp. 351-355
Copyright © 2014 Global Advanced Research Journals

 

Full Length Research Paper

The Effect of Time of Harvest on the Damage Caused to Cowpea by the Storage Bettle,Callosobruchus Maculatus (FAB.) (Coleoptera: Bruchidae)

M. Owusu-Akyaw¹, P. K. Baidoo². and M. B. Mochiah¹

 

¹ Entomology Section, Crops Research Institute, Kumasi, Ghana, West Africa

² Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana, West Africa.

*Corresponding Author's Email: kblanksin@yahoo.com

Accepted 17 October, 2014

 

Abstract

The effect of time of harvest on the level of damage caused by Callosobruchus maculatus on cowpea was studied. Cowpea ( Vigna unguiculata) (variety Asontem) was planted on 9 raised beds  each measuring 2.4m x 2.4 m, 3 each for  early, mid and late harvests i.e. 60,70 and 80 days respectively. Each plot had 20 plant stands. The plants were sprayed with PAWA (Lambda cyahalothrin) at 5 weeks after germination and with Cymethoate at flower bud and pod formation stages. Harvesting was done by hand-picking pods from the inner rows of plants. The harvested pods were sun-dried and the seeds were removed and stored in sealed transparent bottles. The number of adult weevils emerging were collected and counted weekly for 8 weeks.  Weight loss, percent damaged seeds and the number of holes were noted for each harvest time. Mean number of emerged adults ranged from 1.7 at 60 days of harvest to136.7for 80 days of harvest. Significantly larger number of holes and higher % damage were recorded for the 80 days harvest than the 60 and 70 days harvest (p= 0.0001). Prompt harvest of matured cowpea pods would reduce the destruction of stored cowpea by C. maculatus.

Keywords: Cowpea, Storage Bettle, Callosobruchus Maculatus, Coleoptera: Bruchidae.

 

Download Full Text - PDF