A NEW TOOL that calculates reduced downwind spray buffer zones for some crop-protection products is now available to growers and spray contractors.
The tool is used by applicators in combination with prevailing conditions and other drift-reduction practices, including lower rates and coarser spray qualities, to minimise drift.
The Australian Pesticides and Veterinary Medicines Authority permit PER93132 came into effect last month and runs through to 30 June 2028.
It incorporates a spreadsheet-based spray-drift management tool (SDMT) which currently lists 36 different herbicides, including 24 group 4 herbicides (i.e. 2,4-D), and the insecticide Altacor.
Held by Grain Producers Australia, the permit has come about through collaboration between the Grains Research and Development Corporation, GPA and the National Working Party on Pesticide Application.
“The purpose of it is to…reward best practice by being able to reduce buffer zones through good practice such as using coarser droplets sizes (and) reducing the boom height,” APVMA director Hugh Dawick said in a video accompanying the permit’s release
The permit and SDMT calculator apply to aerial as well as ground applications.
Boon to efficiency
GRDC chemical regulation manager Gordon Cumming said the permit allows a move away from “worst-case scenarios” currently printed on chemical labels, but without threatening aquatic and vegetation areas.
“Most labels have a buffer zone statement, which can range from zero to 400m, and everything in between,” Mr Cumming said.
“This defines the downwind distance within which pesticide application must not occur between the outer edge of the boom and the sensitive area.”
“What the permit and calculator enables you to do, for example, when spraying a wheat crop with a canola crop downwind is to calculate a reduced buffer zone distance through the use of several drift reduction strategies.
“These strategies might include a reduced product rate, using a coarser spray quality, lowering the boom height or only spraying when there is a reduced maximum wind speed present.
“If you punch those things into the calculator, you might find that can spray up to the fence line, instead of having to come back another day when the wind is coming from a different direction.”
“It’s a reward for best practice if you undertake drift-reduction strategies combined with taking weather conditions into consideration, and it can reduce the unsprayed area you have to leave.”
Mr Cumming said the new permit therefore has significant potential to aid spray efficiency.
“It could mean your buffer zone has gone from 200m to 80m, or that you can spray right up to the fence line.”
“You might plan to do that strip you had to leave as a buffer zone when conditions are favourable, but the weeds might get away on you in the meantime.”
Users must subscribe to APVMA news updates and the pesticides newsletter to ensure they use the latest version of the modified SDMT, and are asked to retain a copy of the output to include in spray records.
Both APVMA and GRDC have both stressed the permit does not allow “off-label” use.
Source: APVMA, GRDC