Alerts › Weed Alerts ›

What is new and different with weed control in North Carolina?

July 9, 2010
by Travis Gannon and Fred Yelverton

Travis Gannon and Dr. Fred Yelverton

Products containing MSMA (monosodium methane arsonate) will be phased out in the near future. MSMA applications to residential and athletic facilities will no longer be legal after December 31 2010 while other use sites such as golf courses, sod production, and roadside turf may use longer with imposed restrictions. As it stands currently, all MSMA applications in turfgrass will be illegal after December 31 2013. Our current interpretation is EPA has an "open ear" to the benefits of MSMA-containing products and may change their standing on this matter; however, this is the most current update on this policy.

Also, we are excited about several new herbicides. Bayer introduced Celsius which contains iodosulfuruon, dicamba and thiencarbazone spring-2010. This is a great addition to warm-season turfgrass managers toolbox and one of the greatest attributes is all warm-season turfgrass species (excluding carpetgrass if you manage as a desirable) in North Carolina are tolerant! Celsius offers great broadleaf weed control of many common turfgrass weeds. For cool-season turfgrass managers, DuPont is scheduled to launch Imprelis fall-2010. Imprelis contains aminocyclopyrachlor (auxin-mimic herbicide) and offers great control of many common perennial and annual broadleaf weeds in North Carolina.

Finally, it’s not too early to start thinking about annual bluegrass control. Arysta Life Sciences is set to launch amicarbazone fall-2010. Amicarbazone is a selective herbicide that can be used alone or in combination with paclobutrazol to suppress/control annual bluegrass in bentgrass putting greens as well as other areas. We have evaluated amicarbazone extensively and believe it will be a great fit for turfgrass managers in North Carolina.

For annual bluegrass control in overseeded areas, we continue to receive calls each year from turfgrass managers who obtain unacceptable annual bluegrass control with prodiamine (Barricade, Quali Pro prodiamine, etc.) applied 8 weeks prior to overseeding. We observe some variability in our research trials as well from year to year and even from location to location within years; however, prodiamine (0.5 lb ai/a) applied 8 weeks prior to overseeding remains to be an acceptable treatment averaged over trials. For turfgrass managers who desire to enhance annual bluegrass control, we have evaluated sulfonylurea herbicides applied within 2 weeks of overseeding in addition to prodiamine applied 8 weeks before overseeding. Rimsulfuron (TranXit GTA), trifloxysulfuron (Monument), and foramsulfuron (Revolver) are labeled for annual bluegrass control prior to overseeding bermudagrass with perennial ryegrass and when used in combination with prodiamine have provided great annual bluegrass control. Consult individual labels as overseeding restrictions vary. Another treatment that has performed well in our trials is prodiamine 8 weeks before overseeding followed by ethofumesate (Prograss, Poa constrictor, etc.) applied in November. As always, consult and follow label directions when using pesticides.