No abstract

Abstract:Harvested grains suffer enormous damage from insect pests during storage. Their protection in storage has been the subject of many studies including the search for resistant varieties. Screening of many seed varieties had led to the successful isolation of strains that are resistant to insect pests in some African countries. Amongst grain legumes, three out of the 12,000 cowpea (Vigna unguiculata (L.) Walp.) varieties screened were found to be effectively resistant to two cowpea bruchids (Callosobruchus maculatus F.) and C. subinnotatus (Pic.). Out of 31 Bambara groundnut (Vigna subterranea Thou.) varieties screened, 6 were found to be resistant to these bruchids. Similarly, four varieties of groundnut (Arachis hypogea L.) were found to be resistant to both Indian meal moth (Plodia interpunctella Hubner) and rust red flour beetle (Tribolium castaneum Herbest). Among the cereal grains, 175 maize (Zea mays L.) varieties were investigated and 28 found resistant against both the larger grain borer (Prostephanus truncatus Horn.) and the maize weevil (Sitophilus zeamais Motschulsky). These studies revealed that host-plant resistance is a very good method of combating pest depredation in storage. It is perhaps the easiest, most economical and effective means of controlling insect pests on stored grains as there is no special technology which has to be adopted by farmers. The expenses to the farmer are limited because he only has to buy the seeds and no environmental hazards are involved. Furthermore the method is quite compatible with other methods of control.Keywords: Host-plant resistance, resistant varieties, groundnut, cowpea. ‫ﻭﺍﻟﻌﺎﺌل‬ ‫ﺍﻟﻨﺒﺎﺕ‬ ‫ﺒﻴﻥ‬ ‫ﺍﻟﻌﻼﻗﺔ‬

No abstract

The research was conducted in the year 2016 at the Entomology laboratory of the Department of Crop Protection, Bayero University Kano to assessed the bioactive effect of physic nut, Jatropha curcas L. leaf powder on Callosobruchus subinnotatus (Pic) infesting stored bambara nut, Vigna subterranea (L.) Verdcourt. The study was also aimed at comparing the effectiveness of the leaf powder with conventional chemical insecticide (pirimiphos-methyl). In a 2×2 factorial experiment, the leaf powder and pirimiphos-methyl were admixed with bambara nut seeds. The first factor (leaves) had two (2) levels (0.0 and 0.5 g/20 g seed) while the second factor (pirimipos-methyl) also had two levels, with and without the standard rate of application (0.00 and 0.01 g/20 g). These were laid out in a Completely Randomized Design and repeated three times. Results showed fumigant, repellant and contact effects were best exhibited in seeds treated with the leaf powder admixed at the rate of 0.5g, but was not significantly different from seeds treated with pirimiphos- methyl. In conclusion, appreciable level of protection on bambara nut seeds was achieved using the leaf powder of J. curcas applied at 0.5 g/20 g bambara nut seeds during storage.Keywords: Bioactive, Callosobruchus subinnotatus, bambara nut, Jatropha, fumugant

The research was conducted in the year 2016 at the Entomology laboratory of the Department of Crop Protection, Bayero University Kano to assess the biocidal and damage reduction effect of leaf powder from physic nut, Jatropha curcas L. caused by Callosobruchus subinnotatus (Pic) on stored bambara nut, Vigna subterranea (L.) Verdcourt. Also, the study aimed at comparing the effectiveness of the plant product with conventional chemical insecticide (pirimiphos-methyl). Factorial experiment of 4×2 levels (leaf powder at the rates of 0, 0.5. 1.0 and 1.5 g, with and without addition of the synthetic chemical at 0.01 g/20 g bambara nut seed) were laid out in a Completely Randomized Design and repeated three times. Results showed that, admixture of 0.5g leaf powder proved effective in causing high biocidal effect and reduced seed damage. However, this was statistically same with seeds treated with 1.0g leaf powder. Comparatively, all treatments were statistically different from the untreated control seeds but similar with the check treatment. Highly significant (p<0.001) persistent effect was observed in seeds treated with 1.5g leaf powder mixed with 0.5g seed powder at 60 days after treatment (DAT) without any negative effect on seed viability. This was also statistically similar in all other treatments apart from the untreated control. In conclusion, appreciable level of protection on bambara nut seeds was achieved using leaf and seed powder of J. curcas applied at different mixture rates and singly. Therefore, it is recommended that for effective management of C. subinnotatus infesting bambara nut, farmers could use 1.5 g leaf powder or 1.0 g seed powder per 20 g bambara nut seeds singly each. Alternatively, 0.5:1.0, 1.0:1.0 or 1.5:0.5 leaf/seed combinations could be used for safe bambara nut storage.Keywords: Biocidal, Callosobruchus subinnotatus, bambara nut, Jatropha, damage, insecticide