Effect of Arbuscular Mycorrhizal Fungi Inoculation on the Growth of Sweet Potato (Ipomoea batatas) in Niger State

Sweet potato (Ipomoea batatas) is a food security crop grown extensively in the North Central geopolitical zone of Nigeria, including Niger State, where it serves as a staple for rural communities. Arbuscular mycorrhizal fungi (AMF) are soil microorganisms known to form beneficial symbiotic associations with plant roots, enhancing nutrient uptake, particularly phosphorus, and improving plant growth under low-input conditions. This study evaluates the effect of AMF inoculation using three commercial inoculant formulations (Rhizophagus irregularis, Glomus mosseae, and a mixed-species formulation) on the growth and storage root yield of sweet potato in Minna, Niger State. A field experiment was laid out in a randomized complete block design with four treatments including an uninoculated control and three replications. Growth parameters and storage root yield data were collected at vine closure, mid-season, and harvest. Results indicate that inoculation with the mixed-species AMF formulation significantly increased storage root yield by 38 percent and improved phosphorus uptake compared to the uninoculated control. The study recommends the use of mixed-species AMF inoculants as a low-cost, environmentally sustainable input for improving sweet potato production in Niger State. Keywords: sweet potato, Ipomoea batatas, mycorrhizal fungi, inoculation, Niger State