Development of a hand tractor powered de-topper cum digger for onion crop

Abstract

To enhance mechanization in onion harvesting for small land holdings and to increase the annual working hours of hand tractors, a topper cum digger (TCD) unit was developed. This unit simultaneously tops onion leaves and digs up the topped onion bulbs, and is designed to be mounted on 7.5 to 9.70 kW hand tractors. The de-topping unit was mounted at the front, while the digger cum vibratory conveying unit was attached to the rear of the hand tractor, replacing the tiller unit. The de-topping unit included a wire-type cutting unit, telescopic shaft, and linear actuator, and was powered by the hand tractor’s flywheel using belts and pulleys through a bevel gearbox. The digger cum vibratory conveying unit featured multiple V-shaped digging blades, a vibratory conveyor, two sets of oval-type agitators, a pair of rotary discs, and a set of gauge wheels with a hitching arrangement. It could be operated satisfactorily at a maximum forward speed of 1.16 km/h. The height of cut above the crown and depth of bulbs were found to be 31.35 ± 7.0 mm and 69.15 ± 3.1 mm, respectively. The de-topping efficiency, digging efficiency, and damage percentage of onion bulbs were found to be 80.19 ± 2.76%, 90.4039 ± 3.03%, and 8.91 ± 2.00%, respectively. The actual field capacity and fuel consumption were 0.042 ha/h and 0.99 ± 0.27 l/h, respectively. The performance of the developed TCD unit was found to be satisfactory and could be used effectively by small landholding farmers.

Keywords

• Onion crop
• de-topper cum digger
• digger cum conveyor
• digging efficiency
• de-topping efficiency
• Design