We have received a few questions about Liberty and whether to use the high rate of Liberty alone or apply a lower rate and tank mix with clethodim for improved wild oat control. Eric Johnson, weed biologist with AAFC in Scott, Sask., says, “I don’t think that there is rate of Liberty that would provide as consistent control as the Liberty-clethodim tank mix, unless you have group-1 resistant wild oat. My recommendation would be to use this mix, unless you have predominately group-1 resistance, in which you would want to go with the high rate.”
What about applying a high-rate of Liberty to water-stressed crop? “I am not that concerned about the plants being stressed with a high rate. If there is some injury, the injury will be transient and the crop will recover,” Johnson says.
As for timing, he says control the weeds as quickly as possible. “Another flush of wild oat is possible, but based on the fields I have seen, the canola emergence is excellent this year. With the good moisture conditions, the canola crop should provide total ground cover quickly and a second application may not be required.”
The key with tank mixing is to know the weeds you’re targeting. Does the field have a lot of grassy weeds? Are the wild oats group-1 resistant? If thistles are common, consider an application of clopyralid (Lontrel).