There are a number of new herbicides and herbicide combinations available for weed management in 1997. Several herbicides have not received registration at this time and these products, despite pending registrations, will not be discussed in this article.
Several older products for weed control in corn have new names. CyPro and CyPro AT are generic cyanazine and cyanazine plus atrazine, respectively. Bromox and Moxy are generic brands of bromoxynil while Bromox AT and Moxy AT are bromoxynil plus atrazine prepackage mixtures.
The phase-out of cyanazine continues and rate limitations have been established. In 1997, a maximum allowable rate of cyanazine is 5 lb. active ingredient per acre. The maximum allowable rate is reduced in 1998 and 1999 to 3 lb. and 1 lb. active ingredient per acre, respectively. Cyanazine may be sold through September 30, 2002, and used through December 31, 2002.
- Authority Broadleaf and Canopy XL are prepackage mixtures of sulfentrazone and chlorimuron ethyl (5:1) and is registered for soil applications in soybeans. Applications can be early preplant, preplant incorporated and preemergence. Do not apply to soils with a pH that is greater than 6.8. There is a 10-month rotation interval for corn on soils appropriate for these herbicide mixtures.
- Cover (sulfentrazone) will be sold with Synchrony STS by DuPont for weed control in soybeans. Cover will be soil-applied for control of eastern black nightshade and common waterhemp.
- Dual II Magnum is a new formulation that contains the active stereoisomer of metolachlor. This allows the use rate to be reduced to 62.5 percent of the older formulation. Eventually, there will be Bicep II Magnum and Bicep II Lite Magnum available. However, in 1997, Dual II Magnum will be limited in availability.
- FulTime is a prepackage mixture of microencapsulated acetochlor (TopNotch) and atrazine (3:2) plus dichlormid. The product will be positioned for early preplant or preemergence, broad spectrum weed control in reduced tillage and no tillage corn production systems.
- Headline is a co-packaged product of Poast Plus (sethoxydim) and Laddok (bentazon plus atrazine). Headline will provide broad spectrum postemergence weed control in SR (sethoxydim-resistant) corn hybrids. The co-pack should be very useful in woolly cupgrass management programs.
- Hornet is a prepackage mixture of flumetsulam and clopyralid and was sold as Broadstrike Plus in 1996. Hornet is registered for preemergence and postemergence applications in corn and should provide broad spectrum broadleaf weed control. Applications can be made to corn up to 24 inches and weeds up to 8 inches.
- Liberty (glufosinate) is registered for broad spectrum, postemergence weed control in Liberty Link corn and soybeans. Liberty has no residual activity but will control most annual weeds effectively.
- Matador has the same active ingredient and formulation as Assure II (quizalofop) but is registered by FMC. Matador will provide postemergence grass weed control in soybeans.
- Skirmish has the same active ingredient and formulation as Classic (chlorimuron ethyl) but is registered by FMC. Skirmish will provide postemergence broadleaf weed control in soybeans.
This article originally appeared on pages 22-23 of the IC-478 (3) -- April 7, 1997 issue.