University of Illinois

No. 1/March 21, 1997

New Soybean Herbicides for 1997

As with field corn, several new herbicides or herbicide names will appear on the market for 1997. The following is a brief outline of these products. For detailed information, consult the respective herbicide label.

Authority Broadleaf or Canopy XL 56.3DF (5:1 sulfentrazone: chlorimuron) will be soil-applied in soybeans at 5.1 to 7.9 oz/A for broadleaf weed control. Do not use on soils with pH greater than 6.8. The early emphasis will be in areas of ALS-resistant waterhemp.

Cover 75DF (sulfentrazone) is DuPont's brand of Authority, to be sold with Synchrony STS. The Authority component is to be soil- applied for control of eastern black nightshade and waterhemp.

Action 4.75 DF (fluthiacet-methyl), a postemergence herbicide similar to Resource, may be registered for soybeans in 1997 and corn in 1998 at use rates of 1.5 to 2.25 oz/A. It is very active on velvetleaf but also may provide some control of pigweed and lambsquarters.

Expert 75DF (oxasulfuron) is a postemergence ALS-inhibiting herbicide for broadleaf control. Registration in time for use in 1997 is not expected. The field use rate will be 1.5 oz/A alone or when tank-mixed with Action.

FirstRate 84DG (cloransulam- methyl), when registered, will be either soil- or foliar-applied for broadleaf weed control. Rates will range from 0.6 to 0.75 oz/A for soil applications and 0.3 oz/A for foliar applications. FirstRate provides good control of common and giant ragweed.

Raptor (imazamox) will be applied postemergence at 4 to 5 fl oz/A of 1E or 1 oz/A of 7ODF. Raptor has less persistence, plus greater control of grasses and lambsquarters, than Pursuit. Sales in 1997 probably will be in areas where Pursuit restricts recropping to certain vegetables.

Steel 2.59EC is a premix of Pursuit Plus (imazethapyr + pendimethalin) and 0.5X rate of Scepter (imazapyr) for soil applications at 3 pt/A. The Scepter component improves cocklebur control. In 1996, Steel was available as a copack.

New names for 1997:

Matador (quizalofop) and Skirmish (chlorimuron) will be FMC's private brands of Assure II and Classic, respectively, for postemergence use in soybeans.

Flexstar HL 1.88S (fomesafen) is used at the same rate as Reflex 2S. Last year, Flexstar IE had methylated seed oil (MSO) formulated with the active ingredient, but Flexstar HL (high load) has the MSO removed. The MSO should be added back to Flexstar HL.

Marshal McGlamery and Aaron Hager, Department of Crop Sciences, (217)333-4424