Comparative effects of garlic (allium sativum) bulb and bulb coat powder on maize weevils (sitophilus zeamais)

In Nigeria, maize serves as a staple food and a good source of carbohydrates, protein, vitamin B and minerals, hence, the need to protect it against Sitophilus zeamais. This study was conducted to determine the phytochemical properties and insecticidal potentials of Allium sativum bulb and bulb coat powders against Sitophilus zeamais. Allium sativum bulb and bulb coat were collected, dried, and pulverized into fine powder. A 0, 2.0, 3.0, 4.0, and 5.0g of the plant powder were used. Each treatment had 16 newly emerged maize weevils. The weevils were mixed with 250g un-infested maize grains in 500ml bottles and kept at room temperature. Mortality was observed for 7 days at 24 hours intervals post treatment. The experiment was laid out in a Completely Randomized Design and treatments were replicated three times. Data obtained were analyzed using a one-way ANOVA and means were separated using Duncan multiple Range test. The results revealed that both parts showed significant percentage mortality (P ≤ 0.05). The results showed that as the dosage of the bulb powder increased from 2 - 5g, percentage mortality increased from 16-32.8%. For bulb coat powder, percentage mortality increased from 16.5-32.1%. The control showed mortality of 3.0 and 2.8% for the bulb and bulb coat powders, which were significantly different (P < 0.05) from the mortality in treated maize. The most effective dosage for both powders is 5g. Based on the results obtained, Garlic bulb and garlic bulb coat could be used in the management of Sitophilus zeamais infestation.