Design and development of hydraulic controlled tractor front mounted twin conveyor onion (Allium cepa) digger

In India and many developing countries harvesting of onion (Allium cepa L.) crop is done manually which is cumbersome and time-consuming. The tractor-operated front-mounted twin conveyor onion digger was designed and developed during 2019 in Divisional Workshop (Farm Machinery and Power Engineering) at Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand. It had five blades made of mild steel (320 mm × 150 mm × 12 mm size) bolted to the base plate instead of one single share to strengthen the share. Onion and soil were separated over conveying unit. Power from the rear PTO (Power take-off) of a tractor to the front-mounted digging unit was conveyed through a power transmission unit which consisted of a gear reduction unit, V-belt and pulley arrangement, and 40 mm diameter of the propeller shaft. The lifting, lowering, and depth were controlled with the help of two single-acting hydraulic cylinders. The biometric and physical properties of onion bulbs (Agri found light red) were found average with equatorial and polar diameter, plant height, neck thickness, and weight of onion dry leaves as 36.19 and 37.19 mm, 284.05 mm, 6.80 mm and 30.19 g respectively. The average soil cone index, moisture content, and bulk density (before transplanting and harvesting) of soil were observed to be 1 kg/cm2, 17.22,12.58%, and 1.50, 1.38 g/cm3 respectively. The performance evaluation in the field found a maximum percentage of exposed and minimum damaged bulbs as 82.55% and 13.51% respectively, at a forwarding speed of 1.5 kmph and conveyor speed of 2 kmph. The field efficiency of the machine was 87.46%.