Vineyard spray technology put to the test in wind tunnel and field trials

A new factsheet and workshop will reveal the latest advice and research results from spray application trials being undertaken at University of Queensland (UQ) and wider field studies.

University of Queensland senior research fellow, Dr Andrew Hewitt is leading the two-part project, which includes screening dozens of current and new spray systems at UQ’s Gatton campus wind tunnel.

‘This allows us to use controlled conditions, when testing the two major components of spray systems we are looking at – the hardware and chemistry – and how they interact to affect the spray droplet size spectra and drift potential’, Dr Hewitt said.

‘The hardware comprises nozzles of various conventional, air induction and hybrid types.

‘The chemistry comprises active ingredient of various pesticides and inert adjuvant chemistries as used in Australian vineyards’.

The second part of the trial involves field studies in South Australia, where the best systems from the wind tunnel tests will be evaluated for deposition and drift.

‘In addition, novel sprayers are compared against conventional axial fan air-blast sprayers’, he said.

‘These include electrostatics for canopy attraction and wrap-around deposition on all canopy surfaces, recycle sprayers for reducing losses to the ground, and key adjustments to air volumes, velocities and turbulence intensity for canopy penetration.

‘We are also looking at the best ways to calibrate equipment and deliver the optimal dose of chemical to the target’.

The research trial’s major focus is to develop spray application products that are formulated for better atomization and spreading/sticking on the canopy.

‘Technologies are also being optimised for delivery of products to the canopy without off-target losses through drift and runoff’, he said.

‘The best of both worlds occurs when the two are developed in union and we are working on bridging that gap’.

Dr Hewitt said environment and economic concerns are driving demand for new spray application outcomes.

‘Surveys have shown that urban encroachment into rural areas is on the rise and awareness of spray drift and exposure is rapidly increasing in many parts of Australia’, he said.

‘This drives a lot of regulatory pressure for change in spraying without losses to the environment.

‘The Australian regulatory bodies, such as the Australian Pesticides and Veterinary Medicines Authority and local and regional governments, continue to respond to issues of spray exposure to humans and aquaculture with more regulatory considerations and it is our hope that these will be based on the best science and allow choice in applications’.

Dr Hewitt said the models currently used by regulators did not offer choice as they were based on old “worst case” application systems from studies in the USA several decades ago.

‘New data will allow smaller sizes for no spray buffer zones. In this way, economics can also play a part because more land can be farmed when using better spraying systems and application practices’, he said.

A number of workshops have been organised throughout NSW, Victoria, Western Australia, Queensland and South Australia next month and November.

The GWRDC-funded workshops will will provide the latest information on:

  • spray application best-practice
  • new developments in spray technologies
  • improvements in spray application.

The day will also include discussions around current regional spray application issues, new regulations that affect spray practices, and a practical demonstration of spray application assessment and how to improve spray penetration and deposition.

More details, including dates and locations available here:

Spray workshop