Researchers today are transforming weed control with new precision tools and application techniques that can keep herbicides precisely where they belong. As a result, farmers are able to optimize the performance of herbicides and minimize the small amounts that drift off target as they are being applied.
One of the latest breakthroughs involves low-drift nozzles that can significantly reduce the proportion of very fine (small) spray droplets that are susceptible to drift.
“These low-drift nozzles are really having a revolutionary impact,” says Tom Wolf, a research scientist with Agriculture and Agri-Food Canada and a member of the Weed Science Society of America (WSSA). “Research shows we can reduce the spray that drifts away from its target to less than 0.5 per cent of the applied amount. That’s a decrease of more than 80 per cent compared to conventional sprays.”
The secret is a clever design that reduces the internal operating pressure of the sprayer nozzle and mixes air into the herbicide spray as it is applied.
“We’ve seen nearly 100 per cent adoption among custom applicators in Canada, and up to 50 per cent of the more innovative growers on large farms are using them as well,” Wolf says. “They have clearly found the devices work well in their operations.”
Still, there are obstacles to even broader adoption. Not all weeds and all herbicides respond the same way when changes are made to reduce the number of very fine spray droplets.
“It can be tough to provide practical recommendations to applicators on diversified farms,” Wolf says. “But scientists are meeting that challenge by communicating their research findings to herbicide manufacturers and applicators alike. We’re finding low-drift sprays can be used successfully in the majority of situations an applicator is likely to encounter.”
The secret is a clever design that reduces the internal operating pressure of the sprayer nozzle
Robert Klein, a WSSA member and crop specialist at Nebraska’s West Central Research and Extension Center, recommends combining multiple drift-control strategies in order to achieve optimal results. Listed to the right are eight recommended techniques
“Each of these approaches has its strong points,” Klein says. “In order to make sure we’re using the optimal combination of techniques for each scenario, it is important for scientists, applicators, farmers and manufacturers to communicate closely and share best practices.”