Abstract

Background:
Maize is one of the major cereal crops and is mainly produced in sub-Saharan Africa, such as in Ethiopia. Maize cultivation in Ethiopia is highly involved with post-harvest losses. Traditional shelling requires high labor input, low efficiency, and poor grain quality and yield. The other method was the mechanical type, which is a cost-effective, simple, and labor-saving alternative for smallholder farmers. Melkassa developed a pedal-driven sheller in which the machine performance was not assessed to demonstrate or improve the sheller.

Aim:
This study aimed to evaluate the technical performance of a pedal-driven Sheller to determine its performance for small-scale farmers.

Methods:
The performance evaluation was conducted using a factorial experimental design, incorporating three levels of feed rate and three levels of drum speed, each with replications. The study was carried out on the Limu maize variety. The experimental treatments consisted of three feed rates (500, 600, and 700 kg·hr⁻¹) and three threshing drum speeds (500, 550, and 600 rpm). The key response parameters measured were shelling capacity, shelling efficiency, and grain breakage percentage, all evaluated at the recommended moisture content.

Results:
The shelling capacity increased continuously as drum speeds and feed rates increased. The maximum output reached 1,208.9 kg.hr−1 at a feed rate of 600 kg.hr−1 and a drum speed of 600 rpm, while the minimum output was 742.17 kg.hr−1 (at a feed rate of 500 kg.hr−1 and a drum speed of 500 rpm). The high shelling efficiency across all treatments ranged from 93.02% to 96.64%, with the peak efficiency achieved at a 700 kg.hr−1 feed rate and 500 rpm drum speed. The Sheller machine showed an acceptable breakage rate between 1.03% and 1.18% (the breakage rate rose slightly at higher speeds). The grain’s moisture content remained stable at between 11.25% and 12.06% under all test conditions.

Conclusion:
The pedal-driven maize sheller demonstrates high effectiveness in terms of capacity, throughput, efficiency, and seed quality preservation, with breakage maintained at acceptable levels. Fabricated from locally available materials, it is affordable, portable, and easy to operate, making it particularly well-suited to the needs of Ethiopian smallholder farmers. Adoption of this technology can substantially reduce post-harvest losses, minimize human drudgery, and foster local employment opportunities, thereby contributing to improved agricultural productivity and rural livelihoods.

Key words: Capacity; Pedal driven; Performance; Shelling.