Choosing Soybean Varieties for 2019 Based on Herbicide-Tolerant Traits
An article titled “Picking Beans–a Look at the Many 2019 Herbicide-Tolerant Soybean Options” by Emily Unglesbee was posted by DTN/Progressive Farmer on Oct. 2, 2018. The content of this article provides a summary of the herbicide-tolerant traits that are contained in seeds of soybean varieties that can be selected for 2019 plantings. A brief summary of the article’s content follows.
Roundup Ready 1 varieties. These varieties possess the original glyphosate-tolerant trait that went off patent in 2015. Although this trait has been phased out of company seed stocks, some universities have developed/are developing public varieties with this older trait.
Roundup Ready 2 (RR2) varieties. This trait that was developed in 2009 is still under patent, but is being transitioned to the RR2 Xtend platform to allow for POST application of both glyphosate and dicamba herbicides. Seed companies will still be selling RR2 varieties in 2019.
RR2 Xtend varieties. Variety seeds with this trait are tolerant to both glyphosate and dicamba. The dicamba herbicides that can be POST-applied to these varieties will be re-evaluated for approval in the coming weeks.
LibertyLink varieties. These varieties have tolerance to glufosinate (Liberty) herbicide. This trait is available in Credenz varieties as well as varieties from independent seed companies who are licensed to develop varieties with this trait.
LibertyLink GT27 varieties. These varieties have tolerance to glyphosate, glufosinate, and a new HPPD/Group 27 herbicide being developed by Bayer. The new herbicide, ALITE 27, is not yet registered for soybeans and will only be registered for PRE application once EPA approves it. That means that the glyphosate- and glufosinate-tolerant traits will be the only ones applicable for POST weed control. The 13 available BASF Credenz varieties with this trait will range in maturity from 0 to MG 4.5.
Enlist E3 varieties. These varieties are tolerant to 2,4-D, glufosinate, and glyphosate herbicides. Their availability for widespread planting is awaiting final international import approvals. Varieties in MG’s 0 through 5.8 will be available once all approval hurdles are cleared.
The above herbicide-tolerant traits in soybeans are valuable tools for weed management. However, use of any of these varieties with their unique herbicide tolerances should be coupled with fundamental weed management principles that include 1) scouting fields to properly identify and document weed species that are present, 2) applying all POST herbicides at the optimum weed height designated on the herbicide label, 3) using proper application technology, i.e.–nozzle type, boom height, and spray pressure, and 4) using multiple herbicide modes of action when possible to control problematic weeds and delay or prevent weed selection for resistance to current herbicides.
Composed by Larry G. Heatherly, Oct. 2018, larryheatherly@bellsouth.net