C.O.R.N. Newsletter 2010-39

Callisto Xtra (Syngenta) is a premix of Callisto and atrazine for postemergence use on field corn, seed corn, sweet corn, and yellow popcorn.  Can be applied from emergence until corn is 12 inches tall.

Peak (Syngenta) is now labeled for postemergence use in field corn.  Peak contains prosulfuron, the component of Exceed that provided residual control of burcucumber, so a primary use of Peak in Ohio may be to mix with other postemergence herbicides to improve residual control of this weed.  Peak can be applied to corn up to 30 inches tall, but should be applied as a directed spray using drop nozzles when corn is past the 6-collar stage or more than 20 inches tall.  Crop rotation is restricted to corn where rates above 0.25 oz/A are used or when used north of I-70 and mixed with Spirit.  See label for other recrop guidelines.

TripleFlex (Monsanto) is the same herbicide as SureStart (Dow AgroSciences), just renamed and marketed by Monsanto.  Labels of the two products are also similar.

Authority XL (FMC) is a premix of chlorimuron and sulfentrazone for fall, preplant, or preemergence use in soybeans.  A previously available product, Canopy XL, contained these same ingredients, and was widely used in Ohio.  The ratio of sulfentrazone to chlorimuron is higher in Authority XL compared with Canopy XL, which can result in improved residual control of black nightshade and ALS-resistant waterhemp and marestail.  Can be applied to soils with pH up to 7.6, but recrop intervals are extended to at least 18 months for all crops except small grains where soil pH is 7.2 or higher.

Warrant (Monsanto) contains acetochlor, and is labeled for postemergence application to soybeans and corn, to provide residual control of later-emerging weeds, including annual grasses, pigweeds, waterhemp, black nightshade, and lambsquarters.  Warrant does not control emerged weeds, so it should be mixed with glyphosate in postemergence applications to Roundup Ready crops.  Optimum timing of application in soybeans (mixed with glyphosate) is when weeds are 2 to 4 inches tall and soybeans are at V2 to V3.

Kixor products BASF introduced three new products in 2010 based on a new active ingredient, saflufenacil, a broad-spectrum broadleaf weed herbicide.  Kixor is the overall name for saflufenacil-based herbicide technology.  The three new products included:  Integrity, a premix of dimethenamid (Outlook) and saflufenacil for field corn and popcorn; Sharpen, which contains just saflufenacil and is labeled for corn, soybeans, and wheat; and and Optill, a premix of saflufenacil and imazethapyr (Pursuit) for soybeans.  Changes for 2011 include:  a name change – “Integrity” has been renamed “Verdict”; and Verdict is now labeled for use in soybeans at 5 oz/A (which provides the same amount of saflufenacil as 1 oz/A of Sharpen).  Labels have been changed to recommend only MSO with saflufenacil in burndown situations (regardless of what else is in the mix), whereas the previous labels allowed COC or MSO.

Cleansweep D and Cleansweep M (Nufarm) are premixes of bromoxynil (Buctril), fluroxypyr (Starane), and 2,4-D or MCPA, respectively, for control of broadleaf weeds in wheat, oats, and barley.  Cleansweep D can be applied from the fully-tillered stage of crop growth until (but not including) the jointing stage.  Cleansweep M can be applied from the 2-leaf stage up to and including flag leaf emergence.  Labels do not specify whether these products can be applied in the fall, or applied using 28% as the spray carrier.  Allow 4 months between application and soybean planting.

Huskie (Bayer) controls many winter and summer annual broadleaf weeds in wheat, oats, and other small grains.  Huskie is a premix of bromoxynil and pyrasulfotole, which is an HPPD inhibitor (same site of action as Callisto).  Appy in fall or spring after crop reaches the 1-leaf stage, up to flag leaf emergence.  Apply with AMS (0.5 to 1 lb/A) or UAN (1 to 2 qts/A) for most effective control.  Can be applied using UAN as the spray carrier. The fertilizer solution should not exceed 50% nitrogen, and the nitrogen rate should not exceed 30 lbs/A.  Soybeans can be planted 4 months after herbicide application.

PowerFlex (Dow AgroSciences) is labeled for control of annual grass and broadleaf weeds in wheat.  The active ingredient is pyroxsulam, an ALS inhibitor (group 2).  PowerFlex can be applied in the fall or spring when wheat is in the 3-leaf to jointing stage.  Most effective control results from treatment of grasses at the 2-leaf to 2-tiller stage of growth, and when broadleaf weeds are no more than 2 inches tall or in diameter.  Apply with nonionic surfactant or crop oil concentrate.  PowerFlex can be applied in spray solutions containing nitrogen fertilizer solution (UAN), but the spray solution should not be composed of more than 50% UAN and should not exceed 30 pounds of actual nitrogen per acre. When PowerFlex is applied in spray solutions containing UAN, use a non-ionic surfactant at a maximum of 0.25% v/v, instead of crop oil concentrate or methylated seed oil.  Temporary crop injury may result when liquid nitrogen is used as the spray carrier.  Grass control can be reduced if PowerFlex is mixed with dicamba or amine formulations of 2,4-D or MCPA.  Allow 5 months between application and soybean planting.

Pulsar (Syngenta) is a premix of fluroxypyr (Starane) and dicamba for control of broadleaf weeds in wheat and barley.  Pulsar applied alone has a fairly narrow spectrum of control, and should generally be mixed with MCPA ester or another broadleaf herbicide.  Apply before the jointing stage of wheat (label does not specify whether fall application is allowed).  Pulsar can be applied with nonionic surfactant to improve control under less than optimum environmental conditions, and can be applied in a spray solution containing up to 50% nitrogen fertilizer solution.  Allow 9 months between application and soybean planting.