Evaluation of superior processing oranges for fresh juice with selected chinese rootstocks (CT07006)

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Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.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 processing industry was based on the Valencia orange and many of the plantings in the Riverina were well over 40 years of age, having been established in the 1950’s and 1960’s. The decision to replant with a new Valencia type and rootstock was best achieved with locally derived yield and fruit quality information.

A project was developed between Riverina Citrus, Hort Innovation (which was then Horticulture Australia Limited) and the NSW Department of Primary Industries to establish a semi-commercial block of superior performing Valencia selections from the Riverina region. The project title was: ‘Evaluation of superior processing oranges for fresh juice production with selected Chinese rootstocks.’ Berri Ltd in Leeton maintains long term production and juice quality records that enabled the selection of 6 Valencia types for the trial. The Valencia’s were then propagated onto 3 trifoliata type rootstocks sourced from China and showing promise in evaluation trials at the Dareton Primary Industries Institute. The standard Valencia and trifoliata rootstock available to Australian citrus growers was also included in the trial for comparison.

A site in the Leeton area was chosen for the trial and the existing old citrus orchard cleared and developed for replanting. Tree propagation occurred at Dareton Primary Industries Institute over a two year period and planting occurred in October 2010. Two border rows on either side of the trial were planted with 2 new oranges from China to assess their potential for the Australian processing industry.

The site had also been developed to allow for future mechanical harvesting and acted as a demonstration site for local industry field days and farm walks. The establishment phase of the project was now complete and tree survival had been excellent. The next activity began tree growth rate measurements in late 2011. An application for on-going funding from Riverina Citrus and the then Horticulture Australia Limited was developed in 2012 to allow the long term collection of yield, fruit quality and tree growth information. It was envisaged that after 4 years of cropping and data collection a recommendation on the best Valencia and rootstock combination for replanting could be given to Riverina growers.