Enhancing the Efficacy of Allium (Garlic) Extract and Maize-Legume Intercropping Agroecological Practices in Mitigating the Fall Armyworm Damage on Maize

Abstract

Several biotic and abiotic variables limit the maize yield in Africa. The fall armyworm (FAW), a new invasive pest in Africa, and particularly in Cameroon, has exacerbated the problem. This study was done to demonstrate the fall armyworm control on maize in an intercrop system with legumes, and the locally made organic Allium (garlic) emulsion. In this study, a field experiment was laid out in a randomized complete block design with nine treatments (control, insecticide, Allium (garlic), maize dwarf-bean, maize-dwarf bean insecticide, maize-dwarf bean Allium (garlic), maize-cowpea, maize-cowpea insecticide and maize-cowpea Allium (garlic) and three replicates. Maize vegetative data (plant height, stem girth, and number of leaves) were collected, as well as pest occurrence and severity (fall armyworm) and maize yield. The best outcomes for the fall armyworm control in this study came from maize intercropped with legumes (dwarf bean and cowpea), in combination with either synthetic insecticides or the locally made organic garlic emulsion. Control had the most damaged plants for FAW (14) and the number of damaged plants differed significantly (P< 0.05) across treatments. The highest number of FAW (4 FAW) were found in the control, which differed significantly (P<0.05) across treatments. The maize grain yield ranged from 2.1 tha-1 to 5.7 tha-1 and differed significantly across treatments (P<0.05), with the highest yields (5.7 tha-1) in the maize-cowpea insecticide and maize-cowpea garlic treatments, and the lowest yields (2.1 tha-1) in the control. Conclusively, the maize intercrop with legumes and the locally made organic Allium (garlic) emulsion served as sustainable alternative to the synthetic pesticide that effectively controlled FAW without jeopardizing environmental sustainability and increased maize yield. Keywords: Allium (garlic) botanical, pest incidence, pest severity, fall armyworm (FAW), yield, maize, intercropping.