Kansas State University

  1. K-State Home
  2. »Agronomy Home
  3. »K-State Agronomy eUpdates eUpdates
  4. »eUpdate 561 April 8th, 2016»Status of Roundup Ready 2 Xtend soybeans and herbicide options

K-State Agronomy eUpdates eUpdates

Department of Agronomy

Kansas State University

1712 Claflin Rd.

2004 Throckmorton PSC

Manhatan, KS 66506



Extension Agronomy

Status of Roundup Ready 2 Xtend soybeans and herbicide options

Roundup Ready 2 Xtend (RR2X) soybeans, with resistance to both dicamba and glyphosate herbicides, have been in development for a number of years. RR2X soybeans were deregulated by USDA over a year ago, but the soybeans were not introduced into the market last year because they still had not been approved for export to China or received herbicide approvals. 

Early this year, China granted import approval of dicamba-tolerant oilseeds, which cleared the way for Monsanto to sell RR2X soybean seeds for planting in the 2016 crop season. However, the U.S. EPA has NOT yet approved the use of any dicamba products on RR2X soybeans and it is very unlikely that they will be registered in time for use during the 2016 cropping season. 

Consequently, dicamba can only be used in accordance with currently existing dicamba product labels, which do NOT allow for any in-crop applications to soybeans and require minimum waiting intervals before planting soybeans depending on use rate, precipitation, geography, and specific dicamba product. Applying any dicamba product other than those specifically approved for use on Roundup Ready 2 Xtend soybeans could lead to substantial fines and possible embargo of the treated crop. 

EPA is currently considering the registration of dicamba for use on RR2X soybeans. The approval process includes a public comment period during which anyone can submit their comments in support or opposition of the pesticide registration. This is your opportunity to provide input on the proposed registration of dicamba use on RR2X soybeans. Below is the announcement of the public comment period from EPA and the anticipated timelines. 

“EPA is making available for a 30-day public comment period a proposed regulatory decision to register dicamba for use in controlling weeds on genetically-engineered (GE) dicamba-tolerant cotton and soybeans. This registration would be a new use for the previously approved herbicide dicamba. These GE cotton and soybean plants are the first developed to be resistant to dicamba and are intended to allow farmers to use dicamba to control weeds that have developed resistance to glyphosate and other herbicides.

“Public comments on the EPA’s proposed regulatory decision must be submitted no later than April 30, 2016. Comments may be submitted to the EPA docket EPA-HQ-OPP-2016-0187 at www.regulations.gov. After the comment period closes, EPA will review all of the comments and reach a final decision, which the Agency expects to issue in late summer or early fall.”

Monsanto and BASF have developed new formulations of dicamba with reduced drift potential, which, if approved, will be the primary products registered and marketed specifically for use on RR2X soybeans. The proposed name for the new dicamba product from Monsanto is XtendiMax, and the new dicamba product from BASF is Engenia. Monsanto also plans to have a new glyphosate-plus-dicamba premix named Roundup Xtend.   

It is imperative that all products be used according to label guidelines to avoid legal issues and maintain a positive image for the agricultural industry.


Dallas Peterson, Weed Management Specialist

Phil Stahlman, Weed Scientist, KSU Ag Research Center-Hays

Curtis Thompson, Extension Agronomy State Leader and Weed Management Specialist