Design of a two wheel tractor operated onion harvester

Abstract

Onion is a root crop that had been harvested manually in Ethiopia which was tedious, consumes time, labor-intensive, and costly operation. The main objective of this study was to design, fabricate, and perform the evaluation of a two wheel tractor operated onion harvester to alleviate the above-stated problems. A two-wheel tractor operated onion harvester has not designed specifically in Ethiopia and the designed machines should have cutting disc and collector for effective harvesting operation. The physical properties of onion and soil relevant to the design of the digger were studied and each component of the machine was designed accordingly. The design of the harvester was based on the use of locally available materials to reduce costs. A prototype of the harvester was constructed and tested in the field to evaluate its performance. The performance of the harvester was evaluated based on its efficiency, productivity, and cost-effectiveness. The maximum and minimum digging efficiency of the machine was 97.03% at 1.39km/hr forward speed and 10cm depth of operation and 84.60% at 4.15km/hr forward speed and 5cm depth of operation respectively. The maximum mean damage percentage, missing percentage, drawbar pull, fuel consumption, wheel slip, field efficiency, and field capacity were 4.56%, 11.36%, 2935.4N, 15.51 l/ha, 20.82%, 90.84% and 0.157 ha/h respectively. Based on the results, the machine was found to be acceptable for use by small-scale farmers.

Keywords: Design, fabrication, evaluation, forward speed, depth of operation, onion tuber