Improving the accuracy of the Riverina citrus crop forecast (CT10028)

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Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.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?

Riverina Citrus used a scientific formula to calculate the yearly crop forecast. Over the previous years, this formula had been proven to be mostly accurate in predicting the proposed yield for any given year. The committee at the time, however, wanted to increase this accuracy to within 5 per cent.

The major factor in the calculation of the Riverina Citrus crop forecast was the number of trees, or hectares, of each variety within the growing area. To calculate this number Riverina Citrus was using statistics held in the researchers Arcview GIS system, developed in 2003, through the National Plantings Statistics database project.

Under the project, Riverina Citrus adopted Geographical Information System (GIS) technology, incorporating digital imagery derived from satellite photography, for mapping and the management of detailed citrus planting information. The system was in line with that used in the Murray Valley, and by what was to be adopted nationally through the then Australian Citrus Growers. Riverina Citrus also had an additional partner in the development stages in the Riverina Wine Grapes Marketing Board.

The Riverina Citrus Plantings Database was held in high esteem across all facets of the citrus industry in the Riverina at the time. Not only was the information provided through the database essential in the formulation of the Riverina Citrus crop forecast, but it was used as an important marketing tool across the industry.

Riverina citrus growers found the generation of whole farm plans a valuable service provided by the committee, and were keen to use this service at every possible opportunity, and found it a useful planning tool. The Committee also hoped to offer this tool to the other citrus production areas within NSW.

In 2010, after numerous reported changes in plantings, Riverina Citrus approached Hort Innovation (which was then Horticulture Australia Limited) to financially assist in the undertaking of an update in the satellite imagery, and ground surveying, to assist in reaching the organisations goal of yield prediction accuracy within 5 per cent of the crop forecast.

Although 35 per cent of surveys were yet to be finalised, the reserarcher was able to deduct strong indications as to the trends of the plantings on Riverina citrus properties, and this information continued to be collected into 2012.