Production of high quality coffee has traditionally involved selective hand-harvesting of prime coffee cherry over several months. The labour required to do this has generally restricted coffee production to countries with low labour costs.
Background to Machine-Harvesting in Australia:
Machine-harvesters were developed in Brazil to remove tree-dried cherry in a one pass harvesting operation. Australian coffee pioneers in North Queensland were the first producers in the world to attempt to commercially produce a premium quality, wet-processed coffee from machine-harvested cherries. However, growers had difficulty in synchronising crop ripening, and the harvesters demonstrated little selectivity and poor overall performance. Much of the ripe cherry was left on the trees and the harvested fruit often contained large proportions of immature cherry, resulting in quality problems in the final product. In addition, the low work rates usually achieved and the high capital cost of the harvester made harvesting an expensive process.
To address these problems, research on machine-harvesting of coffee was undertaken as part of the coffee research and development program. The initial aim of the program was to enhance the performance of the harvesters by improving selectivity, improving ripe cherry removal, reducing tree damage during harvest and reducing operating costs. Later the program included another objective: to maximise recovery of prime cherry by manipulating harvest timing using novel techniques. Since then, significant advances have been made in machine-harvesting of coffee. The use of high speed filming and high speed data logging, together with a study tour and an investigation of international developments, led to the launching of a prototype light weight, self-propelled harvester. The design of the shakers in this machine incorporated several major changes.
On the basis of this machine’s demonstrated performance, machine-harvesting is now competitive with hand-harvesting, almost irrespective of labour costs, providing the crop can be managed to achieve acceptable maturity synchronisation.
Further developments in management techniques, such as flowering synchronisation and layer harvesting, will enhance the recovery of prime cherry. We anticipate that machine-harvesting technology will develop rapidly as mechanised harvesting becomes accepted among coffee growers world-wide.