Effects of garlic (Allium sativum L) extracts in the control of maize stem borer (busseolafusca f) in south east Nigeria

Abstract

This experiment was conducted at the Teaching and Research Farm of the Faculty of Agriculture and Veterinary Medicine, Imo State University, Owerri, between May and August 2019. The experiment investigated the effect of garlic (Allium sativum) extracts in the control of maize stem borer (Busseola fusca) in Owerri. The experiment was arranged in a Randomized Complete Block Design (RCBD) with four treatments and three replications. In this trial, various levels of treatments were used. (0ml, 50ml, 100ml, 150ml) and (0g, 50g, 100g, 150g) for crude liquid and crude powder extracts. Proximate analysis was carried out on Allium sativum which revealed the nutritional contents in percentages such as moisture content (62.86), Ash Content (0.90). Phytochemical analysis was carried out which revealed the presence of anti-nutritional constituents in percentages, such as Tannin (0.97), Phenol (0.15), Alkaloid (4.77), flavonoid (1.96), Saponin (1.44), oxalate (3.38), HCN (0.01) and Phytate (0.19). More so, infrared spectroscopy of Allium sativum revealed the presence of bioactive compounds and the different wavelength at which they were absorbed. Such compounds are amines (1032.36 and 3998.00), alkane and alkyl (2935.00), Alkene (1641.00), Aromatic compounds (1406.39), Alcohol (1126.14), Alkyl halides (532.36 and 593.00). data were collected on number of insects, number of plants infested leaf area, leaf area index, plant height, number of leaves, number of fruits per plot, stem girth and fruit yield and subjected to analysis of variance at 0.05% level of significance. The results of the trial revealed that the plots that received 50mls, 100mls and 150mls of crude liquid extracts suppressed number of insects (1.0, 1.3 and 1.0) also, plots that received 50mls, 100mls of crude liquid extract at 1WAT reduced the number of plants infested (0.3 and 0.3) than the crude powder extract (0.6 and 1.0) and these were significantly different (P≤0.05). The lowest mean (51.38kg/ha) and (2.67) in fruit yield and number of fruit per plot were recorded from untreated plots. The plant height showed no significant difference (P≤ 0.05). In this study, Allium sativum reduced the number of insect pests attack (Busseola fusca) on maize plant. This action might be due to the anti-nutritional or bioactive compounds inherent in Allium sativum.