TAGETES ERECTA (L.) ESSENTIAL OIL FLORAL AND FOLIAR EXTRACTS AS POTENTIAL GRAIN PROTECTANTS AGAINST THREE SPECIES OF STORED PRODUCT PESTS

Laboratory tests were carried out using population of Tribolium castaneum, (Herbst), Sitophilus oryzae (L.), Callasobruchus chinensis to evaluate the effectiveness of the African marigold, Tagetes erecta (L.) (Asteraceae) floral, foliar extracts and the essential oil, (floral, foliar extracts and the essential oil)for their toxic effects. The effects of the treatments on adult mortality were observed in contact and vapor toxicity methods. Floral and foliar extracts of T. erecta at dosage of 100 mg/ 20 g diet and the essential oil at 30 ul/ 20 g diet, produced 100% mortality (was observed) in all the test insects, one day after application in contact toxicity method. The low doses of the samples were also effective in causing the mortality but the effects were delayed. However, all the dilutions of T.erecta were highly potent in producing the toxicity in the vapor form. There was 100% mortality of the test insects (was observed) even at very low dosages of floral and foliar extracts (80 mg/ 200 cc) and also the essential oil of T. erecta (25ul/ 200cc) in fumigation method within one day after treatment. The dosages lesser to this, showed a comparatively less toxicity to S. oryzae, T. castaneum and C. chinensis. These results suggest that the essential oil, floral and foliar extracts of T. erecta act as good protectants of the stored grain and can be considered as an alternative to synthetic insecticides.