ISSUE 3  May 21, 1998

HERBICIDE - INSECTICIDE COMBINATIONS

    Emulsifiable concentrate formulations of insecticides can act like oil adjuvants when applied in combination with a herbicide. Past research has demonstrated that Asana or Lorsban in combination with Betanex or Betamix can cause more sugar beet injury than Betanex or Betamix alone. Asana and Lorsban should not be applied in combination with normal rates of Betanex, Betamix or Betamix Progress in situations where sugarbeet injury is a concern. The micro rate of Betanex or Betamix + UpBeet + Stinger + methylated seed oil at 0.5 pt/A + 1/8 oz/A + 1.3 fl oz/A + 1.5% v/v already has an oil adjuvant as a part of the system. Therefore, the addition of Asana or Lorsban to the micro rate would not be expected to cause an increase in sugarbeet injury.

    While Lorsban and Asana act like oil adjuvants, the insecticides are not as effective as commercial oil adjuvants and the insecticides should not be substituted for oil adjuvants in herbicide treatments where oil adjuvants are needed for optimum weed control.

Alan Dexter
ND/MN Extension Sugarbeet Specialist

1.    Stinger has been cleared on canola.
2.    Cheyenne has been approved for aerial application through May 26.
3.    Puma has been cleared on durum wheat.
4.    Puma has been cleared on barley
5.    Tiller has been cleared (Section 3) on barley.
6.    Starane has been cleared on wheat and barley.
7.    Select has been cleared on alfalfa and dry beans (Section 3)
8.    Cobra has been cleared for suppression of white mold in soybeans (Section 3).

Accent Gold 75DF + 83.8 DF (DuPont)
    Mode of action: 3 ALS + 1 PGR
    a.i.: (nicosulfuron (Accent) + rimsulfuron (Matrix) +
    (clopyralid (Stinger) + flumetsulam
    (Python/Broadstrike) = Hornet)
    Crops: Corn
    Comments: One rate of 2.9 oz DF/A gives broad-spectrum grass and broadleaf weed control and suppression of Canada thistle. Restricted to 88 or more day maturity corn varieties. Pioneer released a list of corn varieties susceptible to injury from DuPont corn herbicides. DO NOT use Accent Gold or Basis Gold on 3941 or severe injury will occur. Accent Gold  contains 0.25 oz/A Accent 75DF/A and 0.25 oz/A Matrix 25DF, 4 fl oz/A Stinger, and 0.7 oz/A Python 80DF (2.4 oz/A Hornet). Low rates of active ingredients decrease carryover potential. Does not control ALS resistant kochia because Accent, Matrix and Python are ALS herbicides and Stinger provides poor control. May not control late emerging nightshade.
Cost approximately $20.00/A at 2.9 oz DF/A.

Achieve 40DF (Zeneca)
    Mode of action: ACCase Inhibitor
    a.i.: tralkoxydim (40WDG will be replaced with 80WDG)
    Crops: HRS and durum wheat, and barley.
    Comments: U.S. registration expected during or after use season in 1998. Crop stage restrictions is 2-lf to boot.. 7 to 9.5 oz 80DF/A for wild oat and foxtail control = $12 to $16/A. Wild oat are more susceptible than foxtail. Severe antagonism with SU's and phenoxy amines but may have tankmix options with Buctril, Stinger, and/or MCPA ester. Addition of AMS may increases weed control. Same mode of action as fenoxaprop. Turbo-Charge adjuvant included in separate container. In Canada, premixes of Achieve + Buctril M (Bronate) = Achieve Extra Gold and Achieve + Curtail M = Prevail are available.

Aim 40DF (FMC)
    Mode of action: PPO Inhibitor
    a.i.: carfentrazone
    Crops: Corn (Registration expected in 1998)
    Comments: Contact type herbicide for broadleaf weed control. Narrow weed spectrum (velvetleaf) so will be available only in premix with other broadleaf herbicides such as atrazine to increase broadleaf weed control. Controls ALS resistant kochia.

Avenge (American Cyanamid)
    Mode of action: Diverse - not known
    Crops: HRS wheat varieties have been added to label ONLY at 2.5 to 3 pt/A = 2375, AC Domain, AC Barrie, Anza, Bacup, Brooks, Cavalier, Colusa, Ernest, Forge, Hamer, Hi-Line, Kulm, Lars, McNeal, ND2375, Norlander, Oxen, Rich, Russ, Serra, and Sharpshooter and Yolo.

Axiom DF (Bayer)
    Mode of action: Same as Lasso, Dual, Frontier, etc.
    a.i.: fluthiamide + metribuzin (54.4%+13.6% DF or 4:1 ratio)
    Crops: Corn
    Comments: Registered in April of 1998. PPI or PRE with 4 to 6 weeks activity. Primarily foxtail control plus a few small seeded-broadleaf weeds (same weed spectrum as Lasso, Dual, Frontier, Harness, Surpass). Rainfall is REQUIRED for PRE weed control. Does not appear as active on North Dakota soils as competitive herbicides due to limited rainfall. Must incorporate for consistent weed control.

Balance (Rhone Poulenc)
    Mode of Action: Carotenoid inhibitor
    a.i.: isoxaflutole
    Crops: Corn
    Comments: Registration expected during use season in 1998. Apply only PPI or PRE for wide spectrum grass and broadleaf weed control, including wild proso millet, woolly cupgrass, sandbur, and kochia. Do not apply to corn POST due to severe corn injury. New and unique mode of action - carotenoid inhibitor. May provide better weed control in low rainfall conditions than other PPI or PRE herbicides. Weak on yellow foxtail, sunflower, giant ragweed and wild buckwheat. Requires rain for maximum weed control. Will control small emerged weeds after a rain event due to movement to and absorption through the roots. Provides 6 to 8 weeks residual weed control. Crop rotation restriction currently at 6 months for all rotational crops. However, 1998 carryover field trials in ND gives concern to some rotational crops.

Bromoxynil (Rhone Poulenc, Micro Flo through Terra and Ostlund)
    Mode of action: Photosynthesis II inhibitor
    Several brand names introduced in addition to Buctril and Bronate.
Bromoxynil - Photosynthetic inhibitor - other site
    Buctril - Rhone Poulenc
    Broclean - MicroFlo through UAP/Ostlund
    Moxy - MicroFlo through Riverside/Terra
Bromoxynil + MCPA
    Bronate - Rhone Poulenc
    Bromac - MicroFlo through UAP/Ostlund
Bison - MicroFlo through Riverside/Terra
Bromoxynil + Atrazine
    Buctril + Atrazine - Rhone Poulenc
    Brozine - MicroFlo through Ostlund
    Moxy AT - MicroFlo through Riverside/Terra
Buctril Gel will be discontinued.
A dry ester formulation (20WP) and a dry granule formulation (80WG) are being tested for U.S. registration.

Celebrity (BASF)
    Mode of action: ALS inhibitor + Plant growth regulator
    a.i.: Nicosulfuron (Accent) + dicamba (Banvel 70WDG)
    Crops: Corn
    Comments: Registered in April of 1998. Use rate is 6.67 of DF/A and is equivalent to Acccent at 2/3 oz DF/A + Banvel at 8 fl oz. Includes a dry formulation of dicamba. Label does not recommend but does not prohibit use of oil adjuvant which is different than restriction on Banvel label. Unfortunately, Celebrity label restricts use of adjuvants that cause spray solution pH to change (i.e. Quad 7).

Clarity (BASF)
    Mode of action: Plant growth regulator
    a.i.: dicamba - diglycolamine salt
    Crops: Use expanded to small grains in addition to corn and other registered uses.
    Comments: Heavier salt formulation reduces risk of drift compared to Banvel (dicamba - dma salt), or Banvel SGF     (dicamba - Na salt). Caution: The risk of particle drift is the same as other dicamba formulations.
    Dicamba Herbicide
    Banvel = dicamba - dimethylamine
    Banvel SGF = dicamba - Na+
    Clarity = dicamba - diglycolamine
    Fallowmaster = dicamba - acid + Roundup
    Marksman = dicamba - K+ + atrazine
    Resolve = dicamba - Na+ + Pursuit
    OpTill = dicamba - acid + Frontier

Curtail
    Mode of action: PGR
    a.i.: clopyralid + 2,4-D
    Crops: Corn
    Comments: Registered in May of 1998 only in certain states to help manage sugarbeet rotational issues. Labels allow POST application to corn less than 8 inches tall or 4 visible collars or through directed application to corn between 8 inches tall/5 collars to 24 inches tall. Strong caution that Curtail contain 2,4-D which may cause corn stem brittleness/stalk breakage during windy conditions.

Discover (Novartis) - In U.S.
Horizon (Novartis) - In Canada
    Mode of action: ACCase inhibitor
    a.i.: clodinafop
    Crops: HRS and durum wheat.
    Comments: Registered in Canada. U.S. registration expected in 1999 or 2000. Controls grass weeds. Less antagonism with broadleaf herbicides than fenoxaprop herbicides (Dakota, Cheyenne, Puma, Tiller) or Achieve.

Distinct (BASF)
    Mode of action: Plant growth regulator + Auxin inhibitor
    a.i.: dicamba (Banvel) + diflufenzopyr (2.5:1 ratio).
    Crops: Corn
    Comments: Diflufenzopyr is of semicarbozone chemistry and has an auxin transport inhibitor (ATI) mode of action that synergizes auxin type herbicides (2,4-D, Banvel, Starane, Stinger, Tordon). Use rate of 4 to 8 oz product/A controls most annual broadleaf weeds and gives herbistatic grass suppression. Good to excellent corn safety depending on stage of application. Late applications are more prone to injury. Diflufenzopyr in combination with dicamba or picloram (Tordon) has given excellent control of Canada thistle, sowthistle, and leafy spurge control in NDSU field trials. Registration in corn expected late in 1998.

Richard Zollinger
NDSU Extension Weed Specialist