DESIGN AND DEVELOPMENT OF TRACTOR MOUNTED POTATO PLANTER

Potato is the most important vegetable crop in developing countries. Potato cultivation is a labour intensive work. Human labor is still the main source of power used in agricultural works in Ethiopia. Thus, in manual method of planting there is high wastage of human energy, time and effort. This study was initiated to design, manufacture, test and performance evaluation of a prototype tractor mounted potato planter. The prototype planter consisted of main frame, hopper, casing, furrow opener , metering device , sprocket wheels, 3- point linkage, ground wheels, covering devices, solid shaft, and ball bearings with plummer blocks. The experimental design used was split-split plot at three forward speeds (2.5, 3.6 and 4.8 km/h), hopper fill level of (25%, 50% and 75%) and three tuber sizes (25-35, 35-45 and 45-55 mm) with three replications. Planting space was also maintained at 75.00 cm between rows and 30.00 cm between plants and the average depth of planting 12.50 cm. A tractor was used to carry out field test and the field was tilled to a depth of 25-30 cm and harrowed. The performance of planter was evaluated in terms of mean tuber spacing, coefficient of variation, multiple index, miss index and the quality of feed index. In field test, the performance of planter was also evaluated in terms of effective field capacity and field efficiency. The mean field capacity and field efficiency, were 0.20 ha/hr and 72.22%, respectively. Percent of visible mechanically damaged tubers using the planter were 0.93%, 1.23% and 1.48% for small, medium and large tuber, respectively. Tuber size, tractor forward speed and hopper fill level have significantly (p