Occurrence of Deteriorating Seed-Borne Pathogens and Weevils (Callosobruchus Maculatus(f.) Bruchidae Coleoptera) and Their Economic Impacts on Marketing of Stored Cowpea Grains in Maiduguri, Borno State

Abstract

The experiment was conducted to investigate the economic impacts of fungi seed-borne pathogens and cowpea grain weevil (Callosobruchus naculatus (Fab.) BRUCHIDAE COLEOPTERA) on stored cowpea grains which include kananado, Biu-Fari, Bornoji, Kirikiri Banjara jaa, Warware-Bashi, Bonjera and Rangen. The experiment was conducted in a completely randomized design (CRD) in the Crop Protection Laboratory, University of Maiduguri. Blotter's paper seed plating and Agar methods were adopted for the purpose of the investigation. Each cowpea sample were surface sterilized with 10% Sodium hypochlorite for 1-2 minutes and rinsed thrice with sterile distilled water. Ten (10) surface sterilized seeds were aseptically plated per moistened Petri-dishes using a sterilized forceps and incubated at temperature of 21±2 0 C for 7 days. Results showed that there were significant differences (P≤0.05) on germination percentage, 1000 seed weight (g) and disease incidence among the Cowpea variety seeds tested. Higher germination percentage were observed among Kanannado and Bornoji, while Wareware-Bashi had the lowest from 24 to 120 hours after plating (HAP) compared to other Cowpea varieties respectively. Biu-Fari significantly recorded the highest 1000 seed weight and the highest disease incidence from 72 to 120 (HAP). Bornoji recorded the lowest disease incidence from 24 to 120 (HAP) compare to other varieties respectively. Fungal isolates which include Aspergillus niger, Aspergillus flavus, Mucor racemosus and Trichoderma harzianum were isolated from the infected cowpea seeds and identified. The isolates colony pure culture on Potato Dextrose Ager (PDA) were greenish (Aspergillus flavus), black to dark brown (Aspergillus niger), whitish (Mucur recemoses) and light yellowish (Trichoderma harzianum) respectively Disease causing pathogens posed a dangerous health threat and perforation inflicted on the grains by the weevils can lower the market value. Hence, proper seed handling, disease monitoring and safe storage environmental conditions become very necessary in order to prevent seed damage and contamination by the fungal pathogens and C. maculatus.