Australia
October 18, 2016

Once upon a time we used to argue about whether smoking was bad for your health. We don’t argue about that anymore.

In the world of weeds, we used to argue whether low herbicide rates cause herbicide resistance. We don’t argue about this anymore. Both low rates and high rates of herbicide can cause herbicide resistance, but it seems that low rates are the fast track to herbicide resistance.

Dr Mike Ashworth from AHRI, evolved resistance to 2,4-D in wild radish. Mike started with only a few hundred plants of a known herbicide susceptible wild radish population, and in just four generations of recurrent selection with low doses, quickly evolved 8.6 fold resistance to 2,4-D.

And something unexpected happened as well, along with 2,4-D resistance, this wild radish also became cross resistant to the group B (ALS) herbicides Eclipse (metosulam) and Glean (chlorsulfuron), even though these weeds had never been previously exposed to these herbicides.

This research potentially has major implications for farmers in the USA where new herbicide tolerant crop traits rely on the phenoxy herbicides. So keep the rates up!

Read more

Website: http://www.ahri.uwa.edu.au/

Published: October 18, 2016