Dec. 17, 2010

Following is an update of herbicide changes for the 2011 crop production season. It’s divided into four categories: corn herbicides, soybean herbicides, herbicides labeled for use in multiple crops, and herbicides in other crops/sites.

Corn Herbicides

Callisto Xtra™ [atrazine (3.2 lb ai/gal) + mesotrione (0.5 lb ai/gal)].
Callisto Xtra is a new premix of atrazine and Callisto from Syngenta. It is labeled for postemergence application in field corn, seed corn, silage, sweetcorn, popcorn (yellow), and sugarcane. It can be applied to corn up to 12 inches tall. Mode of action (MoA): Atrazine is a photosystem II inhibitor and mesotrione is an HPPD inhibitor. EPA Reg. No. 100-1359. Restricted Use Pesticide.

Prequel® [rimsulfuron (15%) + isoxaflutole (30%)].
Prequel is a new premix herbicide from DuPont for preemergence use in field corn. Prequel will provide residual broadleaf and grass control in a planned two-pass herbicide program. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. MoA: Rimsulfuron is an ALS inhibitor and isoxaflutole is an HPPD inhibitor. EPA Reg. No. 352-779. Restricted Use Pesticide.

TripleFLEX™ [acetochlor (3.75 lb ai/gal) + clopyralid (0.38 lb ai/gal) + flumetsulam (0.12 lb ai/gal)].
TripleFLEX is a premix from Monsanto for preemergence use in field corn and silage. This product can be applied from 30 days preplant to early postemergence (11-inch corn or 2-inch weeds). TripleFLEX controls both broadleaf and grass weeds and is designed for use in a planned two-pass herbicide program. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. MoA: Acetochlor is a seedling growth inhibitor, clopyralid is a growth regulator, and flumetsulam is an ALS inhibitor. EPA Reg. No. 62719-570-524.

Soybean Herbicides

Authority® XL [sulfentrazone (62.22%) + chlorimuron (7.78%)].
Authority XL is a new premix from FMC. It can be applied burndown (fall or spring), preplant, or preemergence for residual broadleaf control in soybean. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. MoA: Sulfentrazone is a PPO inhibitor and chlorimuron is an ALS inhibitor. EPA Reg. No. 279-3413.

Herbicides Labeled for Use in Multiple Crops

Fierce™ [flumioxazin (33.5%) + pyroxasulfone (42.5%)].
Fierce is a new premix from Valent for preemergence control of broadleaf and grass weeds. It will be labeled for use in soybeans, and no-till and minimum till corn. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. MoA: Flumioxazin is a PPO inhibitor and pyroxasulfone is a seedling growth inhibitor. EPA Reg. No. Registration pending.

Pyroxasulfone is a new herbicide active ingredient that will first be marketed in Fierce™ herbicide. It is a preemergence, seedling growth inhibitor. Users should expect performance and control of a similar weed spectrum as obtained with other seedling growth inhibitors such as metolachlor, acetochlor, and dimethenamid-P (small seeded broadleaves and most annual grasses). There likely will be a number of new products and premixes with pyroxasulfone in future years.

Solida™ [rimsulfuron (25%)].
Solida is a new rimsulfuron product from Cheminova. It is labeled for preemergence and postemergence use in field corn, potatoes, and a number of other crops and sites. MoA: Rimsulfuron is an ALS inhibitor. EPA Reg. No. 67760-105.

Verdict™ [saflufenacil (0.57 lb ai/gal) + dimethenamid-P (5.0 lb ai/gal)].
BASF marketed saflufeancil and dimethenamid-P as Integrity in the 2009 and 2010 cropping seasons. It will now be marketed as Verdict. The Verdict label will require the use of an MSO plus AMS or UAN for optimum performance in burndown applications. In addition to field corn, popcorn, and sorghum, use in soybeans has been added to the Verdict label. When used preemergence in soybeans, the 5 oz/ac rate will provide the same saflufenacil rate as 1 oz/ac of Sharpen; application must occur prior to soybean emergence. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. MoA: Saflufenacil is a PPO inhibitor and dimethenamid-P is a seedling growth inhibitor. EPA Reg. No. 7969-279.

Warrant™ [acetochlor (3.0 lb ai/gal)].
Warrant is an encapsulated acetochlor formulation from Monsanto for postemergence use in soybean and cotton. It also has a supplemental label for postemergence application in corn up to 30 inches. Drop nozzles are recommended if corn is greater than 24 inches. Warrant is a seedling growth inhibitor and is not effective on emerged weeds. The postemergence use of Warrant is intended to provide residual control of late germinating grasses and small seeded broadleaves, such as waterhemp. This will help manage some glyphosate-resistant biotypes and reduce selection pressure for other glyphosate-resistant biotypes. MoA: Acetochlor is a seedling growth inhibitor. EPA Reg. No. 524-591.

Herbicides in Other Crops/Sites

Aminocyclopyrachlor is a new growth regulator herbicide active ingredient developed by DuPont. It controls many annual and perennial broadleaf species and some woody species. It will first be marketed as Imprelis for use in cool season turfgrasses and some warm season turfgrass species. In the future, it will likely be marketed in other products for use in other crops and sites.

Imprelis™ [aminocyclopyrachlor (2.0 lb ae/gal)].
Imprelis is a new product and active ingredient from DuPont. It is labeled for postemergence broadleaf control in cool season turfgrass and some warm season turfgrass. It controls many important annual and perennial broadleaf weeds, including ground ivy. MoA: Aminocyclopyrachlor is a growth regulator. EPA Reg. No. 352-793.

Opensight™ [aminopyralid (52.5% ae) + metsulfuron (9.45%)].
Opensight is labeled for control of susceptible weeds and woody plants in non-crop areas including industrial sites, rights-of-way, non-irrigation ditch banks, natural areas, and grazed areas in and around these sites. Opensight and Chaparral have the same active ingredients and formulation and share the same EPA registration number. MoA: Aminopyralid is a growth regulator and metsulfuron is an ALS inhibitor. EPA Reg. No. 62719-597.

Lowell Sandell
Weed Science Extension Educator, Lincoln
Mark Bernards
Extension Weeds Specialist, Lincoln