By Pamela Sherratt
I recently sat down with Dr. Dave Gardner from OSU to get the scoop on the newer herbicides for weed control. (Note: at time I write this, some are still pending registration.)
Newer herbicides for broadleaf weed control
Arylex is the branded name for the new active ingredient haluaxifen-methyl from Corteva. Arylex is a synthetic auxin herbicide, but in a different chemical class, called Arylpicolinates, and this should help with some herbicide resistance issues that have been observed in turf. It mimics plant growth hormones, and disrupts the weed’s growth process. Arylex is particularly active on plantains but also has good activity on a variety of broadleaf weeds. GameOn combines Arylex with 2,4-D choline (a unique formulation of 2,4-D) and fluroxypyr, and is labeled for control of more than 100 broadleaf weed species, including dandelion, broadleaf plantain, chickweed, clover and henbit. It has lower volatility and reduced odor. The product is also reported to be rainfast in one hour. Note that GameOn is not labeled for residential use.
Flumioxazin has been available for many years, marketed as SureGuard or Broadstar, for weed control in nurseries, container ornamentals or landscapes. Do not, EVER, apply SureGuard or Broadstar to turfgrass (unless it’s dormant bermudagrass). Having said that, researchers at NuFarm have figured out a way to make flumioxazin safe for use in turfgrass, and it is in a newer formulated herbicide called Sure Power. Along with flumioxazin, Sure Power also contains 2,4-D, triclopyr and fluroxypyr. Sure Power is labeled for the control of 250 weed species. It is very effective, but particularly on a couple of weeds (ground ivy and wild violet) that have been very difficult for turfgrass managers to control. Research studies conducted at The Ohio Turfgrass Foundation Research and Education Center show that control of ground ivy after application of this product can exceed 80% within three days and be near 100% at seven days after application. Some issues with injury to turfgrass have been reported. These tend to last about two to three weeks, and are more likely to occur if used during early spring or early fall. Sure Power is a good option for broadleaf weed control either in summer or in late fall, when the grass is green but not actively growing.
Newer products for control of sedges
Pyrimisulfan is the active ingredient in the new Vexis herbicide from PBI Gordon. It is available as a granular formulation for postemergence control of sedges and certain broadleaf weeds. It is a granular formulation, which may be useful if you need to reduce the chances for off-target drift. Vexis is for use on residential and commercial sites, golf course fairways, tees and roughs and sports fields. Since it is a different class of chemistry, it provides a good option for managing weeds that have resistance to ALS-inhibiting herbicides.
Imazosulfuron is the active ingredient in Celero, which is labeled for control of yellow and purple nutsedge, as well as annual sedges and kyllingas. It is marketed more for kyllinga control in southern turf, but does show good tolerance when used on northern turf. Since it is a different class of chemistry, it provides a good option for managing weed resistance.
Dismiss NXT contains carfentrazone in addition to sulfentrazone, the active in Dismiss herbicide. This product is effective for control of sedges and summer annual broadleaf weeds.
Newer products for control of grasses
Methiozolin is a new active ingredient in the herbicide PoaCure that, at long last, the EPA has granted registration. It is very effective for control of annual and roughstalk bluegrass either preemergence or postemergence. It is very safe on cool-season turf. Currently it is labeled for golf turf, but labels for sports and sod farm use may occur in the future. The product has been very effective for annual bluegrass control in OSU trials.
Crew herbicide is a new combination product from Corteva that combines dithiopyr (originally marketed as Dimension) and isoxaben (originally marketed as Gallery). It is safe on cool- and warm-season turfgrasses, and can also be used over the top of more than 400 species of ornamentals that are common to Midwest landscapes. It works as a preemergence herbicide for the control of annual broadleaf weeds, as well as crabgrass, goosegrass and annual bluegrass.
Q-Ball herbicide and Drive herbicide both contain quinclorac. Q-Ball is a new product from NuFarm. Quinclorac can be quite effective on leaf stage crabgrass, which is prevalent until mid June. Exercise caution with this timing though, as sometimes the crabgrass grows back. Alternatively, quinclorac is also effective on late stage (>6 tiller) crabgrass as well. In addition to controlling crabgrass, quinclorac can be quite effective on broadleaf weeds such as dandelion and white clover.
Pamela Sherratt is sports turf extension specialist at The Ohio State University.
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