To receive weekly email notification when the latest issue of the Bulletin is online, click on this link and fill out the form.

New Herbicides and Label Changes for 2001

March 16, 2001

Define 60DF (flufenacet) is labeled for use in field, white, and seed corn. Define controls several annual grass weed species and contains the same active ingredient as one component of Axiom, Domain, Epic, and Axiom AT. Applications may be made early preplant (up to 45 days prior to planting), preplant incorporated, or preemergence (after planting but before crop emergence). Application rates are determined by soil texture, organic-matter content, and application timing, and range from 12 to 21 ounces per acre. Control of broadleaf weed species can be enhanced by tank-mixing Define with a broadleaf herbicide.

Balance PRO 4SC (isoxaflutole) is a liquid formulation of the active ingredient in Balance WDG. Applications may be made early preplant (21 days prior to planting or up to 30 days prior to planting when used in a sequential program), preplant incorporated (do not incorporate deeper than 2 inches), or preemergence (before crop emergence). Applications made after corn emergence can result in severe corn injury. Corn should be planted at least 1.5 inches deep, and the seed must be completely covered with soil and furrow-firmed. Failure to thoroughly close and firm the seed furrow may allow the herbicide to directly contact the seed, which can cause injury. Application rates are based on soil texture, organic-matter content, and application timing, and range from 1.5 to 4.5 fluid ounces per acre. To convert the old WDG rate to the 4SC rate, multiply the WDG rate by 1.5. For example, 1 ounce of Balance 75WDG would be equivalent to 1.5 fluid ounces of Balance PRO. Corn hybrids vary in their tolerance to isoxaflutole.


Outlook 6E (dimethenamid-P) contains the resolved isomer of dimethenamid. The product is labeled for use in corn (field, seed, pop, and sweet), soybean, and grain sorghum (treated seed). Outlook may be applied up to 45 days prior to planting, preplant incorporated, preemergence, or postemergence (up to 12-inch corn, between first and third trifoliolate soybean, but not postemergence on grain sorghum). Outlook will not control emerged weeds, so a tank-mix partner will be needed to control emerged weeds. Lay-by applications in corn (but not sweet corn) between 12 and 36 inches in height are also allowed. Application rates range from 10 to 21 fluid ounces per acre (depending on soil texture and organic-matter content) and are approximately 55% of the Frontier 6E rates. Outlook will be available in limited quantities during 2001.

Guardsman Max 5L (dimethenamid-P + atrazine) contains the same active ingredients as Guardsman but is formulated with the resolved isomer of dimethenamid (Outlook). Application rates range from 2.4 to 4.6 pints per acre, depending on soil texture and organic-matter content. Guardsman Max may be applied from 45 days prior to corn planting until corn reaches 12 inches in height. The product is also labeled for use in grain sorghum if the seed was previously treated with an herbicide safener. Guardsman Max will be test marketed in limited quantities during the 2001 growing season; however, full conversion from Guardsman to Guardsman Max is expected for the 2002 growing season.


Everest 70WDG (flucarbazone) is labeled for postemergence applications in wheat. The grass control spectrum is fairly narrow (green and yellow foxtail, wild oats, ryegrass species), and a tank-mix partner is needed for broadleaf control. Use rates range from 0.41 to 0.61 ounce per acre. Applications should be made when wheat has between 1 and 6 total leaves (1 to 4 leaves on the main stem plus 2 tillers) and must include a nonionic surfactant (0.25% v/v).

Dow AgroSciences

Hornet 68.5WDG (flumetsulam + clopyralid) will replace Hornet 85.6WG. The change in formulation will result in application rates ranging from 2 to 6 ounces per acre. Some confusion may exist with respect to the amount of active ingredient contained in this formulation. Hornet 78.5 represents the active ingredient content of flumetsulam and clopyralid, while 68.5 represents the active ingredient content of flumetsulam and the acid equivalent content of clopyralid.

The maximum postemergence application rate of FirstRate 84WG (cloransulam) has been increased from 0.3 ounce to 0.6 ounce per acre.

Last November, Dow AgroSciences announced it had acquired the acetochlor herbicide product line from Zeneca. Under the agreement, acetochlor brands that are now Dow AgroSciences's include Surpass, FulTime, and TopNotch.


Steadfast 75WDG (nicosulfuron + rimsulfuron) contains the active ingredient of Accent and rimsulfuron in a 2:1 ratio. Steadfast may be applied at 3/4 ounce per acre to corn up to 12 inches in height or exhibiting less than six leaf collars, whichever is most restrictive. Steadfast controls several annual grass and broadleaf weed species. However, because both premix components are ALS-inhibiting herbicides, Steadfast may not provide satisfactory control of ALS-resistant weed biotypes. Applications must include either a crop-oil concentrate or nonionic surfactant as well as an ammonium nitrogen fertilizer. Do not apply Steadfast to corn grown for seed, popcorn, or sweet corn.

Harmony GT 75DF (thifensulfuron) contains the same active ingredient as Pinnacle 25DF, which has been discontinued. Harmony GT may be applied to soybean and cereals. In wheat and barley, the application rate of Harmony GT ranges from 0.3 to 0.6 ounce per acre, and applications should be made after the crop is in the 2-leaf stage but before the flag leaf is visible. Applications to cereals should include a nonionic surfactant (0.25 to 0.5% v/v), unless a liquid fertilizer solution is used as the total carrier. For soybeans, Harmony GT may be applied at 1/12 ounce per acre after the first trifoliolate has expanded fully. Always include a nonionic surfactant or crop-oil concentrate (under dry conditions or during cool weather) and an ammonium nitrogen fertilizer. Soybean injury is more likely when a crop-oil concentrate is used.

A reduced rate (0.25 ounce per acre) of Synchrony STS 42DF (chlorimuron + thifensulfuron) may be applied to any soybean type, including non-STS varieties. When applying 0.25 ounce of Synchrony STS to non-STS soybean varieties, add nonionic surfactant (0.25% v/v) instead of crop-oil concentrate.


Several label changes have been made to the Aim 40WDG (carfentrazone) product label to reduce the likelihood of significant corn injury. These changes include (1) do not make applications within 6 to 8 hours of precipitation, (2) spray tips should be a minimum of 18 inches above the crop and sprayers operated to avoid the application of excessive herbicide directly over the rows or into the corn whorls, and (3) use drop nozzles only in seed-corn production fields. Aim may also be applied postemergence to grain sorghum (through 6-leaf stage) at 1/3 ounce per acre, and soybean (up to third trifoliolate) or wheat (up to jointing) at 1/3 to 2/3 ounce per acre. Do not include crop-oil concentrate with postemergence applications. The label recommends a post-directed application in soybean, as severe soybean injury can result if Aim comes in contact with soybean foliage.

Command Xtra (3 lb a.i. clomazone and 4 lb a.i. sulfentrazone) will be available as a co-pack in 2001. Command Xtra is a soil-applied herbicide for control of certain grass (Command) and broadleaf (Authority) weed species. Application rates will vary according to soil texture and range from 0.25 lb to 0.375 lb a.i. sulfentrazone and 0.5 to 0.75 lb a.i. clomazone per acre.

Gauntlet is a co-pack containing the active ingredients of FirstRate (0.84 lb a.i.) and Authority (0.75 lb a.i.). Gauntlet may be applied early preplant (up to 30 days prior to planting), preplant incorporated, or preemergence (prior to soybean emergence) for control of broadleaf weed species. Application rates are determined by soil organic-matter content and range from 0.25 to 0.31 lb a.i. sulfentrazone and 0.6 to 0.75 lb a.i. cloransulam.


Amplify 84WDG (cloransulam) contains the same active ingredient as FirstRate. Application rates range from 0.6 to 0.75 ounce per acre soil-applied or 0.3 ounce per acre postemergence.

Roundup Ultra Max (glyphosate) will replace Roundup Ultra. Ultra Max contains 5 lb a.i./3.71 lb acid equivalent/gallon, whereas Roundup Ultra contains 4 lb a.i./3 lb. acid equivalent/gallon. Ultra Max contains the same formulated additive system as Ultra.

Syngenta (formed by the merger of the agricultural divisions of Novartis and Zeneca)

Gramoxone Max (paraquat) will replace Gramoxone Extra. Max contains 3 lb a.i./gallon compared to 2.5 lb a.i./gallon in Extra.

Touchdown (glyphosate) contains the same active ingredient as Touchdown 5 but is formulated as the diammonium salt instead of the trimesium salt. Touchdown contains 3 lb acid equivalent/gallon, whereas Touchdown 5 contains 3.4 lb acid equivalent/gallon. Touchdown can be applied postemergence to glyphosate-resistant soybean varieties and corn hybrids. Common postemergence application rates will be in the 1.5- to 2-pint range.

Callisto (mesotrione) registration is expected during the third quarter of 2001.


Valor 51WDG (flumioxazin) registration is expected sometime during the spring of 2001. Valor will be labeled as a soil-applied soybean broadleaf herbicide with a similar mode of action as sulfentrazone (Authority).--Aaron Hager and Christy Sprague

Author: Aaron Hager Christy Sprague

The Pest Management and Crop Development Bulletin
Executive Editor: Kevin Steffey, Extension Entomologist

Subscription information: Phone (217) 244-5166 or email
Comments or questions regarding this web site: