By Mark Loux, OSU Extension herbicide specialist
Bayer recently made changes in the name, price, and some rates for glufosinate products. The product “Ignite 280SL” has been renamed “Liberty” (it’s deja vu all over again). The formulation has not changed — just the name. The price of Liberty has increased by about 20%, but there are apparently some rebates associated with the purchase of LibertyLink soybeans that make it more economical to use.
While the current label does not reflect this yet, Bayer is also recommending a minimum rate of 29 ounces per acre for POST applications in LibertyLink soybeans. The rates for burndown use or POST use in corn have not changed.
In our research with LibertyLink soybeans, the 22-ounce rate has often been adequate for POST applications where a broad-spectrum residual herbicide has been applied at planting. The higher rate should provide more effective control of giant ragweed and annual grasses, although it is not likely to overcome the weakness of Liberty on barnyardgrass, yellow foxtail, and certain other grasses. These should be controlled with residual grass herbicides applied at planting, or by mixing a POST grass herbicide with Liberty in POST applications. Moderate to high populations of giant ragweed will still be most effectively controlled with two POST applications of Liberty, similar to the best strategy when using glyphosate in Roundup Ready soybeans.