Development and Testing of Onion Digger and Picker

Abstract

We have been proposing an onion harvesting system using stationary onion topper. In order to accomplish this harvesting system some developments of onion harvester, which are able to handle the onions un-topped are necessary. This report summerized the developing investigations on the onion harvesters and the results of some field tests.
1. Onion digger (Fig. 1)
This self-propelled type machine digged out the onions at working width of 1.25m and made a windrow of onions.
Power to drive this digger was provided by gasoline engine of 5.5PS.
The dimensions of this machine was 2.95m by length, 1.9m by width and 1.45m by height, and it was 620kg in weight.
In field tests, the percent damages of onion bulbs were null and stripped bulbs were 0.2-1.3% at working speed of 0.18-0.45m/s. Onions used in the study planted by direct cultivation.
This machine harvested the onions (at the rate of 16a per hour cat a condition of working speed of 0.45m/s and field efficiency of 83%).
2. Onion picker
This pull-type machine gathered the onions, made in windrow left for field curing, and put them into big container of which capacity was about 900kg.
Gathering and loading operation were done by independent gasoline engine of 4.5PS.
The dimensions of this picker was 4.37m by length, 1.87m by width and 2.35m in height, and it is 1100kg in weight.
Field tests using topped onion showed following results: the damaged onion bulbs of 0.8-1.1% and stripped bulbs of 0.4-1.4% at working speed of 0.23-0.44m/s (quantity of harvest was 9.2-18.5ton/hr.).
In the case of un-topped onions, the percent damages of onion bulbs were 0.8-1.0% and stripped bulbs were null at working speed of 0.16-0.23m/s (quantity of harvest was 8.4-12.9ton/hr.).
This machine harvested topped onions at the rate of 14a/hr, and un-topped onions at the rate of 13.7a/hr.