Practices in Focus: Precision Spray
Queensland horticulture growers face increasing pressure to achieve effective spray coverage while also managing input costs, environmental conditions, compliance requirements and off-target risk.
A series of practical on-farm workshops delivered in Queensland throughout 2025, supported growers to strengthen knowledge and skills of spray calibration, spray coverage assessment and spray unit set-up. The workshops were delivered in response to grower demand for hands-on guidance, received during peer-to-peer activities in North Queensland, where participants identified a need for practical support to calibrate their own spray equipment, and improve efficacy.
Held on commercial farms using host growers’ spray rigs, the workshops gave participants the opportunity to see spray performance in real time, discuss challenges relevant to their own operations and test practical adjustments using water-sensitive paper. Don Thorp from HortSpray led the sessions, which were coordinated through the Hort360 Great Barrier Reef (GBR) Best Management Practice (BMP) project. The project, which is coordinated by QFVG and funded by the Queensland Government, assists growers to improve spray management for better water quality outcomes in Great Barrier Reef catchments.
PEER-TO-PEER APPROACH FOR GROWER WORKSHOPS
Workshops were held in Ayr, Bowen, Innisfail, Tolga, Evelyn, Gympie, Gayndah and Bundaberg. Workshop content was delivered using peer-to-peer, small group extension practices. It included infield discussion amongst growers as well as practical demonstrations on a broad range of spray-related topics including; product efficacy, agitation, chemical modes of action, nozzle configuration, spray measurement and usage, sprayer design and set-up, target crop and pest considerations, record keeping and operator factors. Additional topics canvassed were emerging innovations such as robotics, drones and simulation tools that may influence future spray practice.
Workshops like these are useful in helping growers make more informed decisions about spray unit performance and improve confidence that applications will be effective and efficient. Ninety-one percent of participants indicated they left the workshops with improved knowledge of spray rig calibration and methods to measure spray coverage results.
WHAT DOES BMP LOOK LIKE FOR PRECISION SPRAYING?
BMP in precision spray practice supports spray efficacy and reduces off-target losses. It includes:
Checking spray coverage using water-sensitive paper and adjusting equipment in response to results
Matching nozzle set-up, fan speed and flow rates to crop type, canopy structure and target zone
Improving canopy penetration by using nozzle configurations suited to upper and lower canopy requirements
Maintaining and cleaning nozzles regularly, and replacing them when performance declines
Monitoring agitation and tractor speed to support consistent coverage and product performance
Using air-assist application methods where appropriate to improve deposition and canopy reach.
WHAT WERE GROWERS SAYING?
The workshops provided a valuable opportunity for growers to reflect on the practical barriers they face when spraying. Common challenges raised by participants included changing food safety regulations and label information, heat, humidity, rain and wind, evolving chemical options, lower canopy penetration in fruiting vegetables, and pressure from thrips, mites and fungal diseases, particularly in cucurbits.
Growers found significant value in seeing the spray coverage tests demonstrated in real time. Feedback highlighted that the water-sensitive paper demonstrations made it easier to understand how quickly spray setup could be adjusted and retested to improve results. Participants described this as one of the most practical and useful parts of the training.
WHAT ROLE DID INNOVATION PLAY?
At the Gympie and Bundaberg workshops, Dr Liqi Han from Queensland Alliance for Agriculture and Food Innovation, University of Queensland, demonstrated how digital tools can be used to improve spray efficiency. Light Detection and Ranging (LiDAR) scans of crops and spray units were used to create digital twins that could simulate changes to nozzle set-up, tractor speed and flow rates. This work aims to improve canopy spray coverage and reduce spray drift through more precise modelling and decision-making. This addition broadened the workshop series beyond current practice, showing growers how digital tools may support more efficient, precise and evidence-based spray management into the future.
BENEFITS OF PARTICIPATING IN WORKSHOPS
Better spray application can contribute to reduced off target movement, improved pest and disease control, more efficient use of inputs and stronger alignment with best management practice expectations.
“When you bring the right people together to discuss practical, relevant issues affecting productivity, growers leave with new tools in their toolkit. Those tools help them navigate the many challenges and decisions they face on-farm, week after week.”
Hands-on training helps growers better understand the relationship between equipment set-up and spray outcomes. It builds confidence in calibrating equipment, interpreting spray coverage results and identifying practical changes to improve efficacy and reduce waste. More broadly, this kind of training supports the horticulture industry’s commitment on improving production efficiency, fruit quality, canopy health and environmental stewardship.
ACKNOWLEDGEMENTS
The Precision Spray workshops were delivered in partnership with host growers across multiple regions. Thank you to the following for hosting a workshop:
Chris Lyne, Mountainview Fresh – Ayr
David Richardson, Richardson Farms – Bowen
Ben and Matt Abbott, Jah Farming – Innisfail
Lawrence Massasso, Rocky Creek Orchards – Tolga
Brad Jonsson, Jonsson Farm – Evelyn
Roy and Clinton Roddau, Roddau Farming – Kia Ora
Matt and Rachael Benham, Top Citrus – Gayndah
Peirson Trust – Bundaberg
These workshops were coordinated through QFVG’s Great Barrier Reef Project and subsidised by SmartAg Queensland.
SmartAg Queensland is a collaboration between the Queensland Farmers’ Federation and the Queensland Government to support Queensland farmers.
