APPLIED RESEARCH
Control of Sedges in Turfgrass: Lots of Sedges, Lots of Options By Scott McElroy, Ph.D., Turfgrass Weed Scientist and Assistant Professor; and Greg Breeden, Weed Science Research and Extension Associate (University of Tennessee)
Y
ellow nutsedge (Cyperus esculentus) and other sedge species are increasing in their prevalence in turfgrass systems. Sedge species such as annual flat sedge (Cyperus compressus) and false-green kyllinga (Kyllinga gracillima) can be found throughout the Southeast and the transition zone (Table 1). Sedges are easily identified by their distinct seedheads, rigid leaves and triangular stems (see photos). Thankfully, with the increase in problem sedges, there has also been an increase in the number of control options available. New herbicides for sedge control Sulfonylurea herbicides are an important component of turfgrass weed management, and with the introduction of several new herbicides in this herbicide family, their importance is growing. Sulfonylurea herbicides are commonly applied in low-use rates (usually measured in ounces per acre) and are relatively safe toxicologically. They are all rapidly absorbed by the foliage of the target weeds, and lasting soil residual effects are usually not a problem in turfgrass.
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TENNESSEE TURFGRASS JUNE/JULY 2005
Manage (halosulfuron) and Monument (trifloxysulfuron) are both sulfonylurea herbicides used for sedge control in turfgrass. Monument can be used only on bermudagrass and zoysiagrass turf. Manage, on the other hand, can be used on numerous cool-season grasses, as well. Image (imazaquin) and MSMA can also be used for control of numerous sedges. In fact, the combination treatment of Image + MSMA is a standard by which we evaluate potential new herbicides for control sedges. So far, a combination treatment of Image + MSMA has always been as effective in controlling sedges as any new herbicide that has come onto the turfgrass-managment market. Summary of past results Year after year, the two best control treatments for yellow nutsedge control — and postemergence control of many other sedges — is Monument at 0.56 oz./acre or Image 11.4 oz./acre plus MSMA 2.67 pt./acre. In our 2004 trials, single applications of both herbicide treatments controlled yellow nutsedge 95%
Email TTA at: tnturfgrassassn@aol.com