Integration of Gamma Irradiation and Some Botanical oils To Protect Cowpea And Chickpea Seeds From Infestation With The Bruchid Beetle Callosobruchus Maculatus

The lethal effect of gamma radiation doses of 0.75 or 1.0 kGy on the adults Callosobruchus maculates reared on cowpeas and chickpeas were slow during the first and third days post-treatments. By increasing the dose to 1.5 kGy, the values of the percent mortality of adults in both seeds 24 h posttreatment were 53 and 40%, respectively. On the other hand, the dose 2 kGy caused sooner mortality for adults post-treatment for cowpeas. Different concentrations from eight plant oils; lemon grass, pinus sylvestris, parsley, fennel, geranium, peppermint, petitgrain and sweet basil, were used for protection of cowpea and chickpea seeds from infestation by Callosobruchus maculates. The results showed that sweet basil and geranium caused 89 and 79 % larval mortality, respectively, in case of cowpeas at concentration 0.5 % with exposure period of 48 hour while 71.0 and 63.33% adult mortality was occurred at the same concentration of both oils in chickpeas. The latent effects of tested plant oils on adult stage when beetles of C. maculatus were fed on seeds treated with the lowest two concentrations (0.0312, 0.0625%) of tested oils, the number of eggs laid per female was decreased in female exposed to all tested oils especially in case of cowpea treated with sweet basil and lemongrass. Most of the tested oils caused high reduction in larval penetration in both types of seeds. The adult weight was non significantly reduced at all treatments. The use of different plant oils leads to reduction in the progeny comparing to the control and sweet basil or geranium was found to be highly effective in decreasing the percentage of emergence (30 and 40% , respectively). No harmful effect was observed on germination of plant oils treated cowpea and chickpea seeds with concentration 2%.