Grower News: New Traits Don’t Automatically Deliver The Highest Yields

In a recent edition of his blog The Soy Report, Dr. Shawn Conley reminds growers that new traits don’t automatically deliver the highest yields.

What’s fueling this discussion of new traits is the announcement of the EPA  to register Dicamba formulations for use on Dicamba Tolerant Crops.

With this announcement, weed scientists are hard at work to identify the best management practices for using this technology—and prolonging its shelf life.

Dr. Conley offers four points to consider in choosing soybean varieties for 2017. In his words:

  1. New doesn’t always mean it is automatically better. The WI Soybean program evaluated 200 RR2Y (Roundup Ready 2 Yield®) and 47 RR2X (Roundup Ready 2 Xtend®) varieties in 2016. On average across all varieties and regions RR2Y out-yielded RR2X by a significant +1.8 BPA (Figure 1.)
  1. Remember every variety must stand on its own. Use independent trial data and pick varieties that not only perform well (we call them **starred varieties**) but also have the traits you are interested in (e.g. herbicide tolerance). Please see the 2016 Wisconsin Soybean Variety Performance Trials  for individual variety performance as we have RR2X varieties starred in each region.
  1. RR2X soybeans are a stack of herbicide traits and not yield traits (i.e., these traits protect yield, not enhance yield). Remember this point with all pest management traits!
  1. Hey Mr. Ivory Tower if I don’t use this technology my yield loss will be a lot more than 1.8 bu per acre. I am fully aware of the amaranthus spp. train wreck across much of the corn belt and mid-south. We are starting to see herbicide resistance move across Wisconsin as well. I just want to reiterate #2 above that every variety must stand on its own as well as remind growers to use multiple modes of action and consider incorporating other traits such as Liberty Link soybeans into your soybean weed management plans. All of the data and models I have seen suggest that the Dicamba tolerant crops shelf-life will be much shorter than the original RR if we don’t mange this technology correctly.


Figure 1. Pooled Herbicide Trait Performance Across WI