Some Engineering Properties of Onion Crop Relevant To Design of Onion Digger

Abstract

Field experiments were conducted to determine the biometric and mechanical properties of onion crop relevant to component designs of machine for its harvesting. The percentage distribution of the onion bulb below the ground surfaces indicated that 94% onion bulbs were within 6 cm depth. The plant length of onion crop ranged from 11.0 to 32.0 cm, with a mean of 17.76 cm, at row-to-row spacing of 14 cm. The average value of equatorial diameter for small onion was 34.5 mm and polar diameter was 33.8 mm, where as these values for medium and large size onion were 49.82, 41.41 and 64.68, 53.20, respectively. The average weight of onion bulbs with leaves were 21, 52 and 112g for small, medium and large sizes and the bulk density was 180, 260 and 290 kg.m-3, in the same order. This helped in estimating the amount of material handled by the elevator of onion digger. The information could be used to design different components of an onion digger.