THE BELOW IS AN UPDATE TO AN ARTICLE POSTED ON MSSOY IN JULY 2018. CHANGES AND/OR ADDITIONS ARE BOLDED.
Thankfully, companies that support soybean production in the US have not quit developing new varieties and products that provide producers with new tools to combat weed and pest problems. In the area of weed control, this is especially important with the current and increasing presence of herbicide-resistant (HR) weeds.
On July 5, 2018, MS Technologies and Bayer announced commercialization of LibertyLink GT27 soybeans. Varieties with this weed control technology have a stacked trait that combines tolerance to Liberty (Group 10) and glyphosate (Group 9) herbicides, plus tolerance to isoxaflutole, the active ingredient in Balance Flexx herbicide (HPPD inhibitor–Group 27) that is labeled for corn. The new HPPDi herbicide under development for soybeans (named Alite27–should be available in 2020) for use in this system will be the first of its kind available for use on soybeans.
LibertyLink GT27 soybeans will be the first to offer the trait that enables over-the-top application of both Liberty and glyphosate herbicides to soybeans, plus use of the above Group 27 herbicide. According to Mark Loux (C.O.R.N Newsletter 2019-03), there is no label for use of isoxaflutole on the GT27 soybean at this time.
The current label for Balance Flexx (click here to access label) indicates it may be applied either preplant, preemergence (PRE), or early-postemergence in corn. It is listed as effective for controlling glyphosate-, PPO-, ALS-, and auxin-HR weed populations. Even more important, the label states that it will control problem broadleaf weeds such as Palmer amaranth and marestail, and problem grasses such as barnyardgrass, crabgrass, fall panicum, and broadleaf signalgrass. It may be tank-mixed or applied in sequential applications with other herbicides.
Indications are that the isoxaflutole herbicide for soybeans, once approved, will only be labeled for burndown and PRE applications to soybeans.
The availability of LibertyLink GT27 soybeans that contain tolerance to herbicides with these three modes of action will be a welcome addition to the weed control toolbox for soybeans in the Midsouth, and should offer a new option for management of HR weeds.
As Dr. Larry Steckel stated in his July 17 UTCrops blog post, “with the Engenia, Fexapan, and XtendiMax labels clearly in question for 2019, it is good that there is another possible Palmer amaranth management tool in soybean.” (Since Dr. Steckel posted the UTCrops article, these dicamba herbicides have been re-registered through Dec. 2020.)
Composed by Larry G. Heatherly, Updated Feb. 2019, firstname.lastname@example.org