Performance Analysis of a Locally Fabricated Maize Sheller for Cooperative Farming Groups in Kwara State

Maize is a staple food crop and significant income source for smallholder cooperative farming communities across the North Central agro-ecological zone of Nigeria, and manual shelling methods remain a limiting bottleneck in the post-harvest value chain. This study evaluates the performance of a locally fabricated motorised maize sheller designed and built by artisan fabricators in Ilorin, Kwara State, and deployed at a cooperative farm in Asa local government area. The sheller uses a threshing cylinder fitted with round metal pegs rotating within a concave screen, driven by a 1-horsepower single-phase electric motor. Performance tests were conducted using three maize varieties commonly cultivated in Kwara, including SAMMAZ 15 and SAMMAZ 29, at moisture contents of 12, 15, and 18 percent wet basis. Shelling efficiency, grain damage rate, shelling capacity, and energy consumption per kilogram shelled were measured following ASABE standards. Mean shelling efficiency was 96 percent at 12 percent grain moisture content, declining to 88 percent at 18 percent moisture. Grain damage rates were lowest at 12 percent moisture, averaging 2.1 percent, and increased to 5.8 percent at 18 percent moisture due to increased kernel deformation. Throughput capacity averaged 380 kilograms per hour. The study recommends pre-shelling drying to below 14 percent moisture for optimal performance and reduced damage losses. Keywords: maize sheller, shelling efficiency, grain damage, cooperative farming, Kwara State.