GCTV14 DRT- Andrew Hewitt Narrator: Tony Crowley
The University of Queensland�s Centre for Pesticide Application & Safety has a special
place in the world of spray drift research. Located at Gatton this modest looking lab
is one of only three research facilities focused on DRTs or Drift Reducing Technologies. Andrew Hewitt: Centre for Pesticide Application
& Safety Uni of Qld We are looking at spray drift for the whole
process here, the droplet size of the nozzle through to actually measuring drift in the
wind tunnel and then in the field. Some of the places we work with overseas are looking
at different parts of that story but for example they do not look at the drift in a wind tunnel. Narrator:
For the past few years the Queensland University team with GRDC funding support has been measuring
and collating data on nozzles, spray formulations, droplet size and behavior, and the variables
affecting spray movement. That data has now been linked to modeling to accurately predict
what previously had to be measured. Its also being shared with the other international
researchers and together they are producing a spray application App for mobile devices. Andrew Hewitt:
We�re working with the US Department of Agriculture and the University of Nebraska
to pool thousands of measurements we have made with thousands of measurements they have
made and now we have got the App programming underway, and we�d expect to have them released
by the end of this year. Narrator:
Chemical companies are also making use of the research findings, factoring them into
their own product research and producing new formulations with DRTs built in. Andrew Hewitt:
Yeah the new formulations that have been developed by several companies both the pesticide and
the adjuvants that go with them are really helping to get better performance in the field.
You know growers can get a better spray, better delivery, better sticking on the leaf and
better uptake and the formulation is critical in that. It affects the atomisation of the
spray, it affects the evaporation and ultimately it will affect how much water they have to
use in their tank. Narrator:
Hot dry air will reduce the size of a spray droplet through evaporation making the droplet
more likely to drift. The Delta T model expresses the relationship between temperature and humidity
and is a tool used by spray applicators to help determine when best to spray. Andrew Hewitt:
What we are finding out now is through the research and associated modeling work that
we are doing that we can put Delta T to work for us in improving our application. And one
of the key ways we do that is thinking about how much water we put in our spray mix. If
we put a high water rate out than we are going to make our own high humidity in the spray
cloud and theoretically and experimentally we find that that reduces the amount of drift
significantly. Narrator:
Andrew Hewitt from the University of Queensland and for more information about this project
email Andrew at this address.