Pesticide spray help on hand

Author: Natalie Lee | Date: 13 May 2014

Help is available to ensure growers get the most effective use from costly pesticides and accurately target weeds, diseases and pests in agricultural crops.

If a ‘temperature inversion’ occurs, pesticide application may be sub-optimal and spray can drift from the application site to sensitive crops.

A temperature inversion is when the air at ground level becomes cooler than higher air. These conditions make it unsafe for spraying due to the potential for spray drift.

Information to help pesticide spray applicators use effective methods that avoid spray drift are contained in a revised booklet published by the Grains Research and Development Corporation (GRDC).

Author Graeme Tepper, of MicroMeteorological Research and Educational Services, said Weather Essentials for Pesticide Application aimed to help those applying pesticides to understand, observe and interpret weather conditions, especially those driven by local micro-climates.

“Typically there is a short window of opportunity to safely and efficiently control weeds, diseases and pests in agricultural crops,” he said.

“The opportunity may be shortened by unsuitable weather conditions.

“It is therefore essential that spray applicators are able to identify and react to weather conditions at a local scale.”

Mr Tepper said pesticide particles far smaller than could be seen by the human eye could drift and cause damage many kilometres away from the site of application.

“The weather factors that are important to the application of pesticides can be significantly and critically different to conditions indicated by forecasts, maps and off-site weather observations,” he said.

“This is especially true for conditions overnight and into mid-morning when surface inversions are likely to exist and local winds develop.”

Mr Tepper said a new three-year GRDC supported research project in WA aimed to develop resources to better detect and alert farmers to temperature inversions so they could make more informed and timely spray decisions.

The Weather Essentials for Pesticide Application booklet is available at (NB. file size is large).

Free hard copies are available by contacting Ground Cover Direct on free phone 1800 11 00 44 or

Contact Details

Graeme Tepper, MicroMeteorological Research and Educational Services
0429 309 508

GRDC Project Code TEP00001

Region West