Increased stone fruit profitability by consistently meeting market expectations (SF12003)
Status: Ongoing project
What’s it all about? Established in 2012, this project has been responsible for the establishment and maintenance of a world-class summerfruit field research facility: the Stonefruit Field Laboratory at DEDJTR-Tatura in Victoria.
The field laboratory has the broad objective to evaluate how orchard management (crop load, radiation interception, rootstock and irrigation) affects fruit quality and its variability (including sweetness, firmness and maturity) in selected varieties of peach, nectarine, plum and apricot.
What’s the latest update? The 2015/16 season represented the fourth season of trials at the Stonefruit Field Laboratory, with the researchers reporting on results at the end of 2016.
In one key set of experiments, the effect of crop load management on three-year old August Flame peach trees and Autumn Bright nectarine trees was assessed under two different canopy systems: Tatura trellis and vertical leader. Based on fruiting level, the crop-load treatments were described as either high (minimally thinned), medium (moderately thinned) or low (heavily thinned).
Some top-level results:
- The researchers note thinning elicited significant differences in crop level, fruit yield and average fruit weight – though uniformity of fruit size was similar among crop load treatments and canopy systems
- In all cases, the low crop load treatment decreased yield and increased fruit size – generating a greater proportion of fruit meeting/exceeding minimum fruit size for export to Asia
- With high crop-load treatments – where there was a high amount of fruit per tree – the researchers described a significant decrease in fruit size and fruit sweetness in both peaches and nectarines, irrespective of canopy system used
- In general, sweetness increased with a reduction in fruiting level – and comparing training systems, fruit sweetness was higher on Tatura trellis in both peaches and nectarines compared to the vertical leader system.
Work is ongoing, and the project also continues to establish and maintain trials into crop load and rootstocks for peaches and nectarines; crop load and canopy management in plums and apricots; and an irrigation experiment on nectarines.
Rootstock and training system to optimise early stone fruit bearing and growth (SF13001)
Status: Ongoing project, linked to Increased stone fruit profitability by consistently meeting market expectations (SF12003)
What’s it all about? Using the Stonefruit Field Laboratory, this project is addressing issues related to the very early years of tree establishment and development until full production. It is generating knowledge on how rootstocks, tree training systems and their interaction with crop load affect the physiology of tree and fruit development, especially fruit size, composition and performance.
What’s the latest update? Data collection and analysis is ongoing, particularly in relation to the rootstock component of project investigations.
In regards to the effects of canopy management and crop load, to date the use of different tree training systems (vertical leader and Tatura trellis) has not been shown to significantly affect canopy variability – from top to bottom and east or west side of the canopy – in regards to fruit size and quality (sweetness and firmness). However heavily thinned trees have produced slightly larger fruit at the top, while heavily cropped trees have produced slightly firmer fruit at the bottom of the canopies. Meanwhile, the distribution of soluble solids concentration has been affected by crop load, but not by canopy system.
Fruit maturity has also been affected by cop load, as measured by a DA meter. Regardless of training system used, heavily cropped trees have had the highest IAD (‘index of absorbance difference’, an index of ripening) and lightly cropped trees have had the lowest. Fruit exposed to the afternoon sun have also been slightly more mature than fruit exposed to the morning sun.
As reported in the last edition of Hortlink, the project team have worked closely with Summerfruit Australia to introduce the DA meter as an innovative tool for assessing fruit maturity, and to enable adoption by growers. Video guides (available here) have been produced to demonstrate their use.
China market readiness and entry (SF16000)
Status: Ongoing project
What’s it all about? This project began in 2016, after the signing of the protocol to export Australian nectarines to China. Its aims have included:
- Ensuring the export readiness of the Australian summerfruit industry through the training of growers, packers and exporters and facilitating the registration and audit of export treatment facilities, orchards and packhouses
- Delivering the market-entry strategy for nectarines into China
- Developing and implementing a monitoring and management program for a range of pests and diseases of quarantine concern to China
- Facilitating industry engagement to finalise market access to China for peaches, apricots and plums.
What’s the latest update? Last year, some project activities included:
- Training. Workshops and webinars were conducted to train interested growers, exporters and third party service providers (tasked to monitor pests and diseases covered under the China protocol). Among others, topics included IPM field control procedures, pest and diseases for monitoring, and orchard monitoring.Attendees were provided with a certificate of attendance. This proof of attendance, and qualification to monitor for relevant pests and diseases, is a requirement by the Department of Agriculture and Water Resources as part of the export audit process.Workshops are to be conducted annually for each export season, with details distributed through industry communication and Hort Innovation channels.
- Facilitation of registrations. Registration forms were distributed, face-to-face advice was given, and ultimately there were registrations for 105 orchards, 53 packhouses and 12 treatment facilities. After auditing, which was completed in early October, 75 orchards, 42 packhouses and nine treatment facilities were registered.
- Market launches, with a significant number of enquiries about Australian stonefruit fielded at international trade shows, including the China Fruit and Vegetable Fair held in the final months of 2016. As detailed in the last edition of Hortlink, the launch received media coverage, with Hort Innovation’s media release available here.
In December, the first-ever stonefruit order for China was packed and sent by sea freight, by Montague.
The first lot of Australian stonefruit to head to China
Comparing stonefruit ripening, quality and volatile composition (SF15001)
Status: Ongoing project
What’s it all about? Beginning at the end of 2015, this project is developing tools and knowledge to assist producers in harvesting, storing and ripening fruit for optimum firmness, sweetness and aroma. There is a particular emphasis on fruit for export.
What’s the latest update? Key activities of the project include identifying and quantifying fruit aroma volatile profiles, and monitoring the response of summerfruit cultivars to storage when fruit is harvested at various maturities, then determining subsequent ripening behaviour.
Recent work has resulted in:
- Maturity classes for various peach and nectarine cultivars continuing to be established, with the use of a DA meter. As used in project SF13001 (described above), DA meters allow the rapid and non-destructive measurement of the precise physiological maturity of fruit, at any point in the production chain. This work will help ensure the supply of consistent, high-quality fruit at all times.
- Continued investigation on the effects of storage, with data from the 2015/16 season now analysed. The researchers report that flavour and aroma volatiles changed substantially in August Flame peaches during storage, with a significant reduction in the major flavour and aroma compounds in the fruit. As key quality parameters, the project will delve into strategies to minimise these volatile losses.
As reported in the last edition of Hortlink, the project has also developed a protocol to sample and measure ethylene in the field, using evacuated vials. The new methodology makes data collection more accurate and affordable for both growers and researchers. It’s explained in text and video here.
Australian Stonefruit Grower Magazine 2016 (SF15003)
Status: Ongoing project
What’s it all about? This project is responsible for the production of Australian Stonefruit Grower magazine. Available quarterly, the magazine communicates the latest updates on R&D levy investments and other industry news to Australian growers.
What’s the latest update? New-look digital issues of Australian Stonefruit Grower continue to be available for download at www.summerfruit.com.au/news. This particular iteration of the project is due for completion at the end of April this year.
Other R&D projects of note…
- Selecting and releasing to industry high quality fresh and dried Australian apricots for export and domestic markets(MT12015), which is a multi-industry project funded by both the dried tree fruit levy and co-contribution (formerly ‘voluntary contribution’) from the summerfruit industry. It is developing apricot varieties that are locally adapted, through a partnership with the South Australian Research and Development Institute (SARDI) National Apricot Breeding Program.