April 10, 2015
Several new herbicides were recently registered for weed control in soybean. These new herbicides do not have an active ingredient with a new mode of action, but are tank mixtures of existing herbicides. A season-long weed management plan should include herbicides with multiple modes of action.
The following new herbicides should be available for the 2015 growing season.
Afforia™ [flumioxazin (40.8%) + thifensulfuron methyl (5%) + tribenuron-methyl (5%)]. This is for burndown and preplant residual control of broadleaf weeds and partial control of annual grasses in soybean. It has two modes of action and rapidly inhibits the growth of susceptible weeds. It can be applied at 2.5 oz/ac a day before planting soybean or at 2.5 to 3.75 oz/ac if applied at least seven days before planting soybean. Crop injury may occur from applications made to poorly drained soils under cool, wet conditions. EPA Reg. No. 352-889. Mode of action groups: 14, 2.
Authority®Elite [sulfentrazone (7.55%) + S-metolachlor (68.25%)]. It is a soil-applied herbicide for control of broadleaf, grass, and sedge weeds in soybeans. The crop rotation restriction for corn and sorghum is 10 months. Do not apply more than 38.7 fl oz/ac per year. EPA Reg. No. 279-3442. Mode of action groups: 14, 15.
Authority®Maxx [sulfentrazone (62.12%) + clorimuron-ethyl (3.88%)]. It can be applied pre-plant or pre-emergence in soybean for broadleaf and partial grass weed control. The application rate is 6 to 9 oz/ac depending on soil texture and organic matter content. EPA Reg. No. 279-9560. Mode of action groups: 14, 2.
Fierce™ [flumioxazin (33.5%) + pyroxasulfone (42.5%)]. Fierce is a new premix for pre-emergence control of broadleaf and grass weeds. The use of residual herbicides can help manage or prevent the development of glyphosate-resistant weed biotypes and reduce early season weed competition. Flumioxazin is a PPO inhibitor and pyroxasulfone is a seedling growth inhibitor. EPA Reg. No. 63588-93-59639. Mode of action groups: 14, 15.
Fierce XLT™ [flumioxazin (24.57%) + chlorimuron (6.67%) + pyroxasulfone (31.17%)]. It provides residual weed control in soybean. It also provides additional burndown activity when used as part of a burndown program. Do not make more than one application per growing season. Do not apply more than 5.25 oz/ac during a single growing season. EPA Reg. No.59639-194. Mode of action groups: 14, 2, 15.
Flexstar®GT 3.5 [fomesafen (5.88%) + glyphosate (22.4%)]. Flexstar GT is a new premix herbicide from Syngenta for pre- and post-emergence control of certain grasses, broadleaf, and sedge weeds in soybean. A maximum of 3.5 pts/ac may be applied in alternate years. MOA: Fomesafen is a PPO inhibitor (Group 14) and glyphosate is an EPSPS inhibitor (Group 9). EPA Reg. No. 100-1385. Mode of action groups: 14, 9.
Marvel™ [fluthiacet-methyl (1.2%) + fomesafen (30.08%)]. It is a new premix herbicide from FMC for post-emergence weed control in soybean. It can be applied at 5 to 7.25 fl oz/ac from pre-plant through full flowering stage (prior to R3). It is a contact herbicide therefore, a good coverage is essential for optimum weed control. Do not apply more than 7.25 fl oz/ac per application and 9.75 fl oz/ac per year. EPA Reg. No. 279-3455. Mode of action group: 14.
OpTill® PRO [saflufenacil (17.8%) + imazethapyr (32%) + dimethenamid-P (63.9%)]. It is one of the Kixor-based herbicides from BASF. This co-pack consists of Sharpen, Pursuit, and Outlook herbicides and features three modes of action. It provides both contact burndown and residual pre-emergence weed control in soybean. EPA Reg. No. 7969-332. Mode of action groups: 14, 2, 15.
Pummel™ [metolachlor (5 lb ai/gal) + imazethapyr (0.25 lb ae/gal)]. Pummel is a new product from Adama to be used for pre-plant or pre-emergence control of annual grasses and many broadleaf weeds in soybeans. The use rate is from 1.6 to 2 pt/ac depending upon soil type and organic matter. EPA Reg. No. 66222-251. Mode of action groups: 15, 2.
Rumble® [fomesafen (1.88 lb ai/gal)]. For post-emergence control of broadleaf weeds in soybeans. Adama. EPA Reg. No. 66222-246. 2012. Mode of action group: 14.
Tailwind™ [metolachlor (5.25 lb ai/gal) + metribuzin (1.25 lb ai/gal)]. For pre-emergence control of annual grasses and broadleaf weeds in soybeans and potatoes. Adama. EPA Reg. No. 66222-245. Mode of action groups: 15, 5.
Torment™ [fomesafen (2 lb ae/gal) + imazethaypr (0.5 lb ae/gal)]. Torment is a new product from Adama that can be applied pre-plant, pre-emergence, or early post-emergence for control of broadleaf and grass weeds in soybeans. The use rate is 1 pt/ac when soil-applied and 0.75 to 1 pt/ac with a minimum 15 GPA carrier volume when applied post-emergence. EPA Reg. No. 66222-249. Mode of action groups: 14, 2.
Trivence™ [chlorimuron ethyl (3.9%) + flumioxazin (12.8%) + metribuzin (44.6%)]. Trivence is a burndown as well as residual herbicide that may be applied pre-plant or pre-emergence to soybean. It has three modes of action and rapidly inhibits the growth of susceptible weed species. It can be applied at 6 to 9 oz/ac depending on soil texture and soil pH. EPA Reg. No. 352-887. Mode of action groups: 2, 14, 5.
More information about the efficacy of these herbicides is available in the 2015 Guide for Weed Management in Nebraska (EC130) available online to purchase at http://www.ianrpubs.unl.edu/sendIt/ec130.pdf. Always refer to the herbicide product label for complete details and directions for use.Amit Jhala, Extension Weed Management Specialist
Stevan Knezevic, Integrated Weed Management Specialist