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Why spray the whole paddock when only the weedy patches need treating?

Sam Trengove from Allan Mayfield Consulting is investigating the use of weed sensing technology to control ryegrass in broadacre crops such as lentil and canola.

“Ryegrass costs the agricultural sector millions of dollars annually in herbicide application and lost production,” he said.

“And with the risk of herbicide resistance, there is added incentive for farmers to control the amount of product being applied.”

Sensors that detect differences in plant growth will be used initially to identify ryegrass density and then Global Positioning System (GPS) technology will map areas of high and low density. Once mapped, variable rate spray technology can be used to apply heavier doses of herbicide on dense patches and lower doses across the remainder of the paddock.

“This technology will enable farmers to tailor control measures to site-specific requirements.”

“Historically farmers confronted with variable ryegrass density across a paddock had two options; use a high cost treatment across the entire paddock to achieve optimal control or use the lower cost treatment and accept the yield losses associated with dense ryegrass patches.

“The use of weed sensing and variable rate spraying provides farmers with the best aspects of both options and allows them to gain the greatest return from their herbicide investment”.
While ryegrass will be the focus of this study, Sam believes there is potential to apply this technology to controlling other weeds, particularly those that are found in dense patches.