Objective colour assessment options for the dried grape industry (DG15001) and Evaluating a visible imaging and near-infrared spectroscopy technique for dried grape colour assessment (DG15002)
Status: Completed projects
What were they all about? Beginning earlier in 2016 and now complete, both of these projects developed and tested a number of different methods for objectively measuring the colour of dried grapes. Their common goal was to provide solutions for situations in which a dispute arises between grower and processor over the subjectively assessed colour, and subsequent grading, of fruit (as does often happen with the less-clear-cut intermediate grades).
Of the methods assessed in project DG15001, one emerged as the most viable: the use of a simple office flatbed scanner to capture images of a bin sample, and a software program to then analyse the images and determine a grade for the batch.
The assessment method proved to be quick, cheap, easy for operators and consistently reliable. The standard light source analysing fruit in a single layer within the scanner means analysis isn’t affected by outside conditions, and multiple scoops from the same bins gave the same answers every time.
A scanned sample of fruit in project DG15001 (above) and the project’s prototype software analysing the basic breakdown of scanned fruit (below)
In project DG15002, the use of a custom-built ‘lightbox’ emerged as the most viable method of objective colour assessment. The researchers designed an imaging box with 3-D custom-printed trays. Dried grapes are loaded into the trays, the box is connected to a digital imaging camera, and then the project’s software does the image processing to give a suggested grading.
The method also proved to be reliable, quick and relatively inexpensive.
Dried grapes in the custom-printed trays used in project DG15002 (left) and the project’s lightbox and computer software set-up (right)
Both projects’ tools underwent testing at Sunbeam’s facility in Red Cliffs, Victoria, back in September. The results supported their usability and consistency, with minor tweaks identified to ensure the approaches deliver what the industry needs.
Full details of these pieces of research (including additional avenues of assessment) can be found in the projects’ final reports, available to order at www.horticulture.com.au/about/resources-publications-final-reports. Final reports are free to Australian horticulture levy payers, registered Hort Innovation members and industry representative bodies.
Evaluation of dried and table grapes varieties (MT15026)
Status: New project
What’s it all about? Recently commenced, this project will deliver new grape varieties for both the dried grape and table grape industries. For dried grapes it will deliver new, consistently high yielding, rain-tolerant varieties targeted to produce a premium light-coloured, globally differentiated product to enhance value.
What’s the latest update? For dried grapes, the project has so far prepared for the evaluation of dried product produced from seedless material established by the CSIRO in previous varietal work at Irymple, Victoria.
At the time of reporting to Hort Innovation, the fruit had been dried, harvest weights had been recorded, and dried samples had been cleaned ready for evaluation. There are 201 genotypes to be evaluated (135 single-vine seedlings and 66 multiplied selections).
The researchers note that while climatic conditions during drying were excellent, there was a significant rainfall event prior to harvest. This produced some rain damage (fruit splitting and drop) in some early-ripening selections, which provided an opportunity to assess their rain tolerance.
New rootstocks to improve production and water use efficiency, sustainability and reduce risks of dried grape production (DG12006)
Status: Ongoing project
What’s it all about? Rootstocks are an important tool to reduce production risks associated with climate variability, salinity and soil-borne pests. Running since 2013, this project aims to deliver new high-yielding, water-use-efficient and drought-tolerant rootstocks. It is also investigating integrated strategies involving high-density plantings and rootstock choice to optimise productivity and water-use efficiency in the dried grape industry.
What’s the latest update? No new milestone report was due in the period since the last edition of Hortlink (Winter 2016). At the time of last reporting, vine performance was assessed at harvest in all bearing rootstock trials for the 2016 season.
All trials were being managed on hanging cane training systems. They included Carina, Sultana and Sunmuscat trials grafted on 11 new rootstock genotypes and three commercial rootstocks, managed with two irrigation treatments (a standard control of 5.6ML/ha and a deficit treatment of 2.5ML/ha). There were also high-density rootstock trials established on a commercial property with Carina and Sunmuscat, which were harvested for the second time, and the long-term Sunmuscat trial grafted on 104 rootstock genotypes.
Results of the new evaluation trials indicated significant potential to identify new rootstocks that maintain high productivity under limited water supply.
Dried grape industry development project stage 2 (DG13001)
Status: Ongoing project
What’s it all about? This project supports an industry development officer (IDO) to, among other things:
- Facilitate the adoption of best-practice production systems and technologies in the industry, in turn supporting growers in lifting crop yields, lowering costs and improving fruit quality
- Ensure the latest R&D results and other relevant management information is extended to growers and other stakeholders, to enhance the industry’s skills base
- Support industry projects related to the evaluation and development of new dried grape varieties, to ultimately enable production of a high-value, differentiated product under a range of conditions.
What’s the latest update? No new milestone report was due in the period since the last edition of Hortlink (Winter 2016). At the time of last reporting the IDO, John Hawtin, had:
- Continued to consult and liaise with growers, undertaking property visits, responding to enquiries and more
- Helped facilitate a number of training-relating activities for the industry, including Field Walks and training on the Dried Grape Approved Supplier Program (the industry’s quality assurance program)
- Prepared industry articles and information sheets, including a draft New Varieties fact sheet
- Continued to build and maintain networks with other IDOs to facilitate the sharing of information
- Been involved in research and on-farm trial activities, including collecting and propagating cutting material to establish mother vines for rootstock work; liasing with growers regarding Sunmuscat vigour decline and death of vines; participating in committee meetings for various research projects; establishing and maintaining a demonstration site for cordon bunch removal using Ethrel at the SuniTAFE farm, Victoria; and more.
A project plan, covering activities to the end of 2016, had also been developed and was underway.
IDO John Hawtin (to the right) at the 2016 Mildura Field Days (above), and John’s propagation of rescued cuttings (below)
Australian dried fruit communications program (MT15031)
Status: New project
What’s it all about? Following on from previous communications work, this project will continue to maintain and improve communication to Australian dried fruit growers and other industry stakeholders. By keeping the industry up-to-date on R&D, news, events and other critical information, its ultimate goal is to facilitate the uptake of R&D by the industry and support decision-making in dried fruit businesses.
What’s the latest update? A number of regular communication channels will continue to be produced and maintained by this project, including but not limited to:
- Quarterly magazine The Vine
- The Dried Fruits Australia website, www.driedfruitsaustralia.org.au (recently redeveloped)
- Fortnightly e-newsletters
- Social media
- The drafting and production of a Dried Fruit Investment Guide.
The latest edition of The Vine magazine
Other R&D projects of note…
» Producing high value dried grapes stage 2 (DG13006), which is now due for completion. A summary of the project’s final report will be included in the next edition of Hortlink.