This is not to say that weed control in herbicide tolerant canola is now, or ever was, a “one and done” proposition – it’s still a balancing act of herbicide tank mixes and spray timing built to target specific weed profiles and tough-to- control weeds.
The latest tool in the weed control toolbox is Optimum GLY – an advanced herbicide-tolerant trait technology that gives farmers the ability to widen the herbicide application window, and increase glyphosate rates, to control a wider spectrum of weeds compared to other glyphosate- tolerant systems.
When you plant Optimum GLY canola hybrids, you can apply up to 2 L/ac. of glyphosate per season, from cotyledon to first flower. That’s higher than TruFlex™ Canola, which allows a maximum rate of 1.33 L/ac., also up to first flower.
How can the Optimum GLY rate be that much higher and not cause crop injury? The short answer is that the Optimum GLY trait essentially deactivates glyphosate in its hybrids, whereas the TruFlex trait amplifies glyphosate tolerance, which helps its hybrids “digest” the herbicide more efficiently. It means that Optimum GLY canola hybrids can sustain higher glyphosate rates without crop injury. You can read more about the exact science here.
The ability to spray increased rates of glyphosate means that, with Optimum GLY, you can control a wider range of weeds, get better activity against them and against tougher-to-control weeds, such as perennial sow thistle, Canada thistle, wild buckwheat, dandelion, foxtail barley and more.
The critical weed-free period in canola is from cotelydons to the 4-leaf stage. This is when maximum yield protection is achieved simply by removing weeds.
With Optimum GLY, you can either apply the full amount (2 L/ac.) of glyphosate in one application from emergence to the 6-leaf stage to fields clean up to and just past the critical weed-free period. Or you can go with two sequential applications of 1 L/ac. from emergence up to first flower, with the second application coming at least 14 days after the first. So, you could apply a full litre per acre of glyphosate in the critical weed-free period then go back later to clean up any late weed flushes, right up to first flower. You can choose the best approach depending on your weed situation and growing conditions.
The flexibility in application timing and herbicide rates make Optimum GLY a powerful tool to keep canola fields clean, from emergence to canopy closure, and maximize the yield potential of your crop. Call your Corteva Territory Manager to find out more.