The Corteva and Pioneer canola research teams in Australia have been working for more than a decade, and finally, in February, we saw a global announcement by Corteva Agriscience that we would see the commercial launch of Optimum GLY trait technology for canola in Australia.
Optimum GLY is an advanced herbicide-tolerant trait technology. It will provide Aussie growers with enhanced weed control and a wider herbicide application window compared to first-generation glyphosate technologies.

What’s new?
The Optimum GLY trait will allow you to apply registered Glyphosates over the top of these canola varieties from emergence to 10% flower.
The benefits include improved crop safety, enhanced weed control and a later window of application to help maximise yield potential.

Compared to the Truflex & Roundup Ready varieties, the Optimum GLY technology uses a different pathway in the plant to give the canola tolerance. This means that you will be able to spray up to 3 applications of glyphosate (in accordance to the label of the registered glyphosate). I.e. Crucial could be used up to 1.8L/ha with a minimum of 14 days between applications.

How does it all work?
If you want to nerd out – the Optimum GLY trait expresses glyphosate acetyltransferase (GAT), which is an enzyme that metabolises glyphosate upon its entry into the canola plant. Basically, it converts glyphosate to a herbicidally-inactive form. This conversion prevents the “herbicidally-active” molecule from binding to EPSPS and stops the critical shikimic acid pathway required for canola growth (Figure 1).
Figure 1. Optimum GLY deactivates glyphosate to survive.

Other glyphosate technologies, like Roundup Ready® canola and TruFlex™ technology, work by utilising a gene that creates an altered EPSPS enzyme in the plant, one that is not inhibited by glyphosate.
So when glyphosate is sprayed, it disables the native EPSPS synthase, but cannot disable the transgenic gene in Roundup Ready® canola and TruFlex™ technology, allowing the shikimate pathway to proceed. (TruFlex™ technology is different from Roundup Ready® canola as it adds an enhancer sequence in the promoter region to heighten transgenic enzyme expression in male (pollen) reproductive tissue).
Figure 2. Roundup Ready® canola and TruFlex™ technology Modes of Action

Optimum GLY technology will be commercially available in Australia in 2024. And you will be required to enter into a Technology Use Agreement (TUA) with Corteva Agriscience.
But if this new technology is something you’re interested in, Pioneer will have a demo site around Tarlee. We will get the chance to check it out throughout the year, so keep an eye out for our invites and also for results in NVTs.

For more info:
https://www.pioneerseeds.com.au/news-and-events/optimum-gly-canola-release

https://www.corteva.com.au/products-and-solutions/seeds/optimum-gly.html