Speed updating gives growers a fast serve of current R&D

In June, as part of Hort Connections 2018, APAL ran its annual Speed Updating event where industry researchers shared key information for growers about their findings.

Funded by Hort Innovation as part of the Australian Apple and Pear Innovation and Adoption Program, this year’s Speed Updating was attended by more than 130 people.

PIPS

The centrepiece of Hort Innovation’s apple and pear levy-funded R&D program is PIPS – the Productivity, Irrigation, Pests and Soils program. PIPS delivers the following six research projects:

  • Tree structure/artificial spur extinction
  • Integrated pest and disease management
  • Improved tree and fruit nutrition for the Australian apple industry
  • Profitable pears: maximising productivity and quality of new pear varieties
  • Physiological, metabolic and molecular basis of biennial bearing in apple
  • Independent program coordination.

In addition to these projects, extension of PIPS and other Australian R&D funded by Hort Innovation is managed by Ross Wilson of AgFirst as part of Future Orchards®.

Biennial bearing

PIPS researchers at Speed Updating included German researchers Professor Jens Wünsche, University of Hohenheim, and Dr Henryk Flachowsky, Julius Kühn Institute. Jens leads the Physiological, metabolic and molecular basis of biennial bearing in apple project along with Henryk and Dr Dario Stefanelli of Agriculture Victoria.

Biennial bearing is characterised as the trees ‘on’ and ‘off’ year and refers to the trees tendency for annual cyclical changes to flowering and cropping behaviour. Biennial bearing is a major problem for apple industries worldwide, Australia included, causing millions in lost production every year.

Jens explained that for a bud to become a floral bud it must go through three specific phases of development at a molecular level the previous year:

  • Phase 1: Induction – molecular and biochemical changes
  • Phase 2: Initiation – morphological changes
  • Phase 3: Differentiation – where the flower is formed

Once these phases occur in the bud, the flowering bud is ready the following spring.

The project is seeking to understand more about what triggers floral bud induction (Phase 1), where otherwise if not triggered will be become a vegetative bud. As Jens explained, floral induction is triggered by a combination of environmental factors, phenological factors and cultural intervention.

The molecular and physiological control of floral induction is controlled by carbohydrates, cytokinins, gibberellins, auxins and a range of integrator genes, repressor genes and identity genes.

Certain genes, such as the TFL1 gene, can be more highly expressed in ‘on’ years which may have a repressor effect on the crop load level the following year. On the contrary, the integrator genes will positively affect floral induction.

The project aims to better understand the physiological and molecular mechanisms that lead to biennial bearing. It will lead to the identification of molecular markers that can be used to help breed new varieties that don’t have biennial tendencies, and the identification of specific compounds that modulate flowering behaviour.

Artificial spur extinction

Dr Sally Bound, Tasmanian Institute of Agriculture, presented her work on the bud thinning technique artificial spur extinction (ASE). ASE represents a paradigm shift in crop load management that can provide a cost-effective means of setting more precise crop loads.

Sally reported that ASE delivered better consistency in cropping, improved fruit dry matter, and improved firmness and soluble solids compared with conventional chemical thinning-based management.

Nutrition and irrigation

Dr Nigel Swarts, Tasmanian Institute of Agriculture, presented on the Strategic Irrigation and Nitrogen Assessment Tool for Apples (SINATA), which is a decision support tool to help growers optimise nutrition and irrigation management.

The tool will incorporate data on different soil physical and hydraulic profiles based on samples collected from Australian apple regions.

Integrated pest management

Agriculture Victoria’s David Williams is leading the industry’s integrated pest management (IPM) project for biological control of codling moth (Cydia pomonella). He reported that a total of 271,000 parasitoid wasps (Mastrus ridens) have been released in all major growing regions where codling moth occurs including Victoria, New South Wales, Queensland, South Australia and Tasmania (not Western Australia because codling moth is absent). David also presented a new project updating the apple and pear IPM manual and developing further IPM training and information resources for the industry.

Blush pears

Dr Ian Goodwin, Agriculture Victoria, demonstrated that colour development in the new blush pear cultivars is very dynamic. Artificial shading reduces red colour but once artificial shading is removed the colour rapidly recovers.

Insect pollination

Dr Romina Radar, University of Armidale, presented on research seeking to determine what are the dominant insect pollinator species of apple, how the different species fare in efficiency for
pollination and how this affects other aspects of fruit production, mainly quality. Romina’s pollination field surveys in the Yarra Valley (Victoria), Stanthorpe (Queensland), Adelaide Hills (SA), and Bilpin and Orange (NSW) show that while over 90 per cent of insects observed visiting apple flowers were European Honeybee (Apis mellifera), other visiting insects included flies, wild bees, lepidopterans (butterflies and moths), wasps, beetles, hermipterans (bugs) and ants.

In other research in Stanthorpe, Romina showed that orchards that were fully netted during pollination greatly reduced visitation rates compared with orchards that had open/partially retracted nets. The research is also investigating what number of pollen grains and what number of visitations are actually required to set fruit, as well as what effects cultivar-to-cultivar crossing has on efficiency and fruit quality. Results have shown that different polleniser cultivars can influence fruit quality.

South Africa to the US

International guests Professor Karen Theron from the University of Stellenbosh and HortGro South Africa, and Assistant Professor Lee Kalcsits of Washington State University in the United States of America also presented at Speed Updating providing a very welcome international dynamic which was highly valued.

Karen presented an overview of South African pome fruit research in the context of the broader strategy specific to the South African apple industry. She emphasised that, in South Africa, a constant stream of well-trained people and a focus on technology and knowledge creation are key to increasing the competitiveness of the industry.

Lee presented his research on calcium nutrition and the association of low calcium levels with the apple disorder bitter pit. He explained the fundamentals of calcium and why there is such an inability to get the non-plant mobile calcium into specific tissues versus other more mobile nutrients such as nitrogen, potassium and magnesium. Lee explained that varieties can have different susceptibility to bitter pit due to their vascular and cellular structure. Also, varietal differences in how long xylem functions during the season influences the ability to carry calcium into the fruit.

Other points

Agriculture Victoria’s John Lopresti provided harvest maturity and storage guidelines to optimise quality and minimise storage disorders for the new blush pear cultivars – ANP-0118 (formerly known as Lanya), ANP-0534 and ANP-0131 (formerly known as Deliza).

Andrew Horsfield, ADAMA, informed participants that Brevis® has been submitted for registration as a thinning agent for apples with the Australian Pesticides and Veterinary Medicines Authority (APVMA). If registered, it will be available for use in Australian commercial apple orchards.

Dr Hannah James, AgroFresh, also informed us that the harvest management tool Harvista® has also been submitted to APVMA for registration in Australia.

Hort Innovation’s Olivia Grey provided a domestic marketing update where a study showed apples have increased their place from number six to number three in a consumer list of favourite snacks. Data on pears showed more pears are being consumed as a mid-morning, lunch and mid-afternoon snack (see page 12 for more updates on marketing).

Dr Anthony Kachenko, also of Hort Innovation, introduced a new agritechnology project led by Swarm Farm in collaboration with ADAMA, Bosch and the University of New South Wales.

Acknowledgements

Thank you to all the speakers for delivering such engaging presentations containing valuable information for the apple and pear industry.

About the Author:

Technical Manager, Apple and Pear Australia Ltd
acrawford@apal.org.au
03 9329 3511