Across the forum, technical speakers explored how orchard management decisions, plant physiology and emerging tools can help growers improve productivity outcomes. Key insights came from Dr Harley Smith (CSIRO), Dr Amnon Haberman (Queensland DPI) and Dr Stephen Trueman (Griffith University), each examining different drivers of yield variability.
> Understanding the biology behind yield consistency
Dr Harley Smith highlighted that improving yield consistency requires a understanding of tree genetics and physiology and orchard systems rather than focusing on single inputs or treatments.
A key message was the importance of carbohydrate supply during flowering and early fruit development. Managing how carbohydrates are partitioned between vegetative growth and reproductive structures plays a major role in fruit set and retention.
Smith explained that seasonal fruit drop is often linked to reductions in carbohydrate availability and hormonal changes within the fruit.
Environmental factors such as temperature and humidity during flowering were highlighted as critical influences on pollination and fertilisation success.
> Plant growth regulators as emerging tools
Dr Amnon Haberman’s presentation explored how plant growth regulators (PGRs) may help growers manage productivity challenges when used as part of broader orchard management strategies.
A central concept was that the effectiveness of any intervention depends on identifying the limiting factor affecting production — reflecting Liebig’s Law of the Minimum.
Key discussion points included:
- The use of paclobutrazol (PBZ) and uniconazole (UCZ) sprays at flowering to improve fruit set and early retention
- Soil applications of PBZ to reduce excessive vegetative vigour
- Potential roles for ethylene inhibitors such as 1-MCP to enhance post-harvest fruit quality
Haberman emphasised that PGRs should be viewed as tools within a wider management system that includes irrigation, nutrition, canopy management, pest and disease control, and pollination management.
> Pollination: unlocking untapped yield potential
Dr Stephen Trueman’s presentation turned attention to pollination biology — an often overlooked factor affecting avocado productivity.
Despite the presence of bees and other insects, many avocado flowers are never pollinated, highlighting the complexity of achieving consistent fruit set.
Key insights included:
- Limited daily overlap between male and female flower phases within cultivars
- The importance of cross-pollination between Type A and Type B varieties
- The role of orchard design and pollinator management in improving outcomes
Trueman emphasised practical actions growers can take, including strategic planting design, introducing bees at the right time, and managing pests and diseases before pollinators are introduced.
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Turning research into practice
Across the day, a common theme emerged: yield consistency is influenced by multiple interacting factors rather than a single solution.
The forum reinforced that incremental improvements — whether through better understanding of tree physiology, targeted use of new tools, or optimising pollination strategies — can collectively drive meaningful gains in productivity and fruit quality.
By combining technical presentations with in-field discussions and peer networking opportunities, the regional forum provided Central Queensland growers with practical take-home strategies and a clearer understanding of how current research can support on-farm decision-making.
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📄 Accessing presentations and resources
Presentations, technical resources and supporting materials from the Central Queensland Regional Forum will be distributed to attendees and will also be published in the BPR Library next week for growers who wish to revisit the content or catch up on key learnings.
📞 Further information
For more information about the event or future Central Queensland activities, please contact CQ Regional Lead Renata Grunennvaldt on 0475 855 445 or via email at renata.grunennvaldt@dpi.qld.gov.au
Acknowledgement
These regional forums are delivered as part of the Avocado Industry Development and Extension Project (AV23010) which has been funded by Hort Innovation, using the avocado research and development levy, co-investment from the Queensland Department of Primary Industries, Western Australian Government Department of Primary Industries and Regional Development, New South Wales Department of Primary Industries, and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.
