New Soybean Herbicides for 2017

New Soybean Herbicides for 2017 March 6, 2017

Soybean field treated with Sonic
Figure 1. Sonic applied pre-emergence at 4.5 oz/acre followed by Enlist Duo applied post-emergence at 56 fl oz/acre in Enlist soybean in a field near McCool Junction.
Soybean field treated with Zidua
Figure 2. Zidua PRO applied pre-emergence followed by Roundup Powermax at 32 fl oz/acre in Roundup Ready soybean at the South Central Ag Lab near Clay Center.

Several new herbicides have been registered for weed control in soybean. These new herbicides do not have an active ingredient with a new mode of action, but they are tank-mixtures of existing herbicides. A season-long weed management plan should include herbicides with Multiple Modes Of Action. (For more information see the newly revised industry Herbicide Classification chart.)

Following are new soybean herbicides that should be available for the 2017 growing season.

Authority®Elite [sulfentrazone (7.55%) + S-metolachlor (68.25%)]. It is a soil-applied herbicide for control of broadleaf, grass, and sedge weeds in soybean. The crop rotation restriction for corn and sorghum is 10 months. It should not be applied at a rate of more than 38.7 fl oz/acre per year. EPA Reg. No. 279-3442. BroadAxe XC has similar herbicide active ingredients as Authority Elite. EPA Reg. No. 279-3442-100. Modes of Acton: 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/acre depending on soil texture and organic matter content. EPA Reg. No. 279-9560. Modes of Acton: 14 + 2.

Soybean field treated with Rowel
Figure 3. Rowel FX applied pre-emergence at 3 oz/acre followed by XtendiMax applied post-emergence at 22 fl oz/acre in Roundup Ready 2 Xtend soybean at the South Central Ag Lab near Clay Center.

Enlist™ Duo [2,4-D choline (24.4%) + glyphosate (22.1%)]. Enlist Duo can be applied only in Enlist corn and in Enlist soybean for control of annual and perennial weeds. Do NOT apply this product in Roundup Ready or Liberty Link soybean. This herbicide is based on Colex-D technology. Products with 2,4-D that do not contain Colex-D technology are  not authorized for use in conjunction with Enlist corn and soybeans. It is a systemic herbicide intended for control of annual and perennial weeds. Apply 3.5 to 4.75 pints of Enlist Duo per acre. Make one to two applications with a minimum of 12 days between applications. In Enlist Soybean, apply 3.5 to 4.75 pints of Enlist Duo per acre. Apply when weeds are small and any time after soybean emergence but no later than R2 (full flowering stage). Do not apply more than 4.75 pints of Enlist Duo per acre per application. Do not apply more than 14.25 pints/acre of Enlist Duo per season. EPA Reg. No. 62719-649. Modes of Action: 4 + 9.

Fierce® XLT [flumioxazin (24.57%) + pyroxasulfone (31.17%) + chlorimuron (6.67%)]. Fierce XLT in Nebraska can only be used in the fields south of Route 30 and east of US Highway 281. This herbicide provides residual control of broadleaf and grass weeds in soybean. It also provides additional burndown activity when used as part of a burndown program. Moisture is necessary to activate this herbicide in soil for residual weed control. Do not apply more than 5.25 oz/acre per growing season. Do not apply additional chlorimuron-containing herbicides to fields treated with Fierce XLT. EPA Reg. No. 59639-194. Modes of Acton: 14 + 15 + 2.

Marvel™ [fluthiacet-methyl (1.2%) + fomesafen (30.08%)]. This 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/acre from pre-plant through full flowering stage (prior to R3). It is a contact herbicide; therefore, good coverage is essential for optimum weed control. Do not apply more than 7.25 fl oz/acre per application and 9.75 fl oz/acre per year. EPA Reg. No. 279-3455. Modes of Acton: 14 + 14.

Presidual™ [S-metolachlor (58.2%) + metribuzin (13.8%)]. Presidul is for control of certain grasses and broadleaf weeds in soybean. The application rate of this herbicide is 2.0 to 2.9 pt/acre depending on soil texture and organic matter content. EPA Reg. No. 1001162-1381. Modes of Acton: 15 + 6.

Warrant® Ultra [acetochlor (30.2%) + fomesafen (7.1%)]. In Nebraska Warrant Ultra can be applied only in counties east of or intersected by US Highway 281. It can be applied as a preplant surface, pre-emergence, or post-emergence treatment in soybean. A maximum of 48 fl oz/acre of this herbicide can be applied in alternate years in soybean fields in these Nebraska counties. It can provide residual as well as burndown activity. This herbicide can be applied only once per growing season. EPA Reg. No. 524-620. Modes of Acton: 15 + 14.

XtendiMax™ [dicamba (42.8%)]. XtendiMax is a new dicamba product to be used on dicamba-tolerant (Roundup Ready 2 Xtend) soybean. The formulation contains Vapor Grip, which reduces the volatility of this product. This product has 2.9 lb/gallon of DGA salt of dicamba in liquid, so 22 fl oz provides 0.5 lb of dicamba, which is equivalent to 16 oz of Clarity and other 4 lb/gallon dicamba products. The minimum application rate for any use is 22 fl oz/ac. The maximum rate per application prior to soybean emergence is 44 fl oz/acre, which is also the total maximum allowed for all applications prior to soybean emergence. The maximum rate per application after soybean emergence is 22 fl oz/acre. The total of all POST applications cannot exceed 44 fl oz/acre. The cumulative application rate per year cannot exceed 88 fl oz/ac. Use of ammonium sulfate, UAN, etc. is not allowed due to their potential to increase the volatility of dicamba. Certain adjuvants can be mixed with XtendiMax and are listed at xtendimaxapplicationrequirements.com. Post-emergence application of XtendiMax can be made from emergence up to and including the R1 stage of soybean growth. Weeds should be less than 4 inches tall at time of post-emergence application. EPA Reg. No. 524-617. Mode of Acton: 4.

Zidua® PRO [imazethapyr (13.45%) + pyroxasulfone (23.06%) + saflufenacil (4.81%)]. Zidua PRO is a premix of Pursuit, Zidua, and Sharpen. It provides contact burndown and residual pre-emergence control of annual grass and broadleaf weeds in soybean. It can be applied from 4.5 to 6.0 fl oz/acre depending on tillage system. It has three modes of action and will be a good herbicide to consider in a resistant weed management program. EPA Reg. No. 7969-365. Modes of Action: 2 + 15 + 14.