This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

The Australian Citrus Industry had been seeking a satisfactory mechanical harvester since at least the 1980s. It was therefore no surprise that when a machine came along that was clearly a big step in the right direction, there was considerable interest in its performance.

Nelson Harvesters Pty Ltd (Nelson) had already designed and built a prototype mechanical harvester, which was originally trialled and used commercially in the olive industry. Nelson’s decision to develop the machine for orange harvesting was encouraged by leaders in the citrus industry. In 2008 (prior to this project’s commencement), the Nelson Harvester (the machine) was trialled commercially on several varieties of juicing oranges in the Riverina district of NSW. In October of that year it was demonstrated at the 2008 Australian Citrus Industry Conference and viewed by 150 growers, representatives of juicing companies and other interested parties.

In order to keep up with and meet the needs of Australia’s rapidly expanding Citrus Industry – specifically for the orange juice industry - modifications were required on the 2008 model of Nelson Mechanical Citrus harvester before being able to consider manufacture or even consider tackling a full season harvest. The modifications aimed to achieve 24 hour harvesting by undertaking the following:

1. Split the conveyor system to allow for quick clearing of blockages
2. Build an overhead conveyor to pass fruit across the adjacent tree row so that the ferry bin trailer need not be located in the same tree row as the harvester as was the present arrangement
3. Replace existing overhead conveyor with one of greater capacity
4. Install a weather proof camera system to monitor discharge system
5. Install longer fishplates to minimise fruit loss
6. Fit a size grading mechanism so as to separate any immature fruit
7. Fit a de-stemmer to overhead conveyor so as processing plant does not need to deal with stems
8. Strengthen elements of the frame where necessary
9. Modify blower system to better remove dead twigs and branch material
10. Replace floor conveyor system with more suitable components with no sharp edges
11. Build new trailer conveyor
12. Install and plumb new hydraulics

The 2009 trials successfully demonstrated that 90 per cent of fruit was collected using the modified Nelson citrus harvester. In this project, a total of 1155 tonne of fruit was harvested with this modified harvester with a daily average of 29.7 tonne, with an average day consisting of 8.6 hr of harvesting time (which equated to a total of 12 hours actually in the orchard). Assuming a second tractor and chaser bin were added in the 2010 season to the harvesting operation, with no further modifications, Nelson harvesters predicted the harvest total to increase by an additional 30 per cent of crop per working day.

These modifications were aiming toward better financial returns for growers, juicing factory and machine operator/owner.