A new liquid formulation of ammonium sulfate fertilizer (AMS) that can improve weed control with over-the-top application of Roundup Ultra and generic glyphosate products on Roundup Ready soybeans, corn and cotton has been announced by AlliedSignal, Inc.
Called Sulf-N-Forcer, it can be tankmixed with any postemergent herbicide that specifies AMS on its label. This also includes Liberty for Liberty-Link corn and Synchrony on Synchrony-tolerant soybeans.
“We’ve known for a long time that we can improve burndown weed control by adding a small dose of ammonium sulfate to glyphosate,” says Dean Collamer, an agronomist with AlliedSignal. “With the rise in planted acres of Roundup Ready soybeans and cotton, we’re discovering that ammonium sulfate can also improve postemergence weed control.”
He says calcium, magnesium and other minerals found in hard water often tie up glyphosate and interfere with plant intake. “When we add AMS to the tank, hard water minerals bind to the AMS instead of the glyphosate, allowing the herbicide to remain in solution and be absorbed by the plant.”
Collamer says AMS can also improve weed control when target weeds are suffering from heat or drought stress. Besides AMS, Sulf-N-Forcer contains a polytex deposition aid to improve coverage on the leaf surface and a defoaming agent to improve herbicide mixability. The product is available in 2 1/2-gallon jugs for convenient storage and handling.