Most of the talk about upcoming herbicide-tolerant traits centers on dicamba and 2,4-D tolerance. This could be because they are first or a bit controversial. Lost in this debate are technologies that will be released from both Bayer and Syngenta. These are Syngenta’s MGI soybean and Bayer’s Balance Bean. Both are tolerant to HPPD-inhibiting herbicides such as Balance and Callisto. But like 2,4-D and dicamba, they will not necessarily be tolerant of the same specific herbicides.
HPPD inhibitors are the newest class of chemistry in the herbicide world and they were discovered over 30 years ago. This illustrates the need for new chemistry in general for herbicides that I have talked about in previous articles. This chemistry was first introduced in Asia for weed control in rice, but has primarily been used in corn in the United States. In particular, Callisto has had success as a substitute for atrazine in the Midwest. Soon this technology will be available in herbicide-tolerant soybeans.
MGI soybean from Syngenta has been modified specifically to tolerate the herbicides mesotrione (Callisto), glufosinate (Liberty) and isoxaflutole (Balance). Although HPPD herbicides have both PRE and POST activity, the most logical approach to this technology will probably be a PRE application of the HPPD component followed by Liberty or other herbicides. The PRE application will likely include a grass herbicide like Dual. Syngenta currently has a product like this in corn called Zemax.
Balance Bean is Bayer CropSciences new herbicide brand for isoxaflutole. The current version of Balance GT soybeans will be tolerant of either glyphosate and isoxaflutole or the latter plus glufosinate. Although Balance GT soybeans have been deregulated for a year now, Bayer is waiting on global acceptance of this GMO trait before introducing a product.
Balance GT beans are about one year ahead of Balance GT soybeans stacked with glufosinate tolerance.
This technology is a separate event from Syngenta’s HPPD soybean and Balance Beans will not currently tolerate mesotrione. This may make Flag the Technology tricky in terms of HPPD tolerance. We are working on color schemes for these beans. Both companies are talking about 2018 or so for a market introduction, so we have some time to work on it.
I believe that HPPD technology will eventually be stacked with either dicamba, 2,4-D or both, probably later this decade, depending on market acceptance and the registration process. In fact, beans exist today that will tolerate HPPD, dicamba, glyphosate and glufosinate, possibly others. This will allow for some extremely effective resistance management and prevention options if growers will adopt a three- to four-herbicide family program. Of course, I suspect that with each new trait added will come at additional costs.
My biggest fear with all the new GMO traits that are coming to market soon is not herbicide drift, or how to keep fields straight and avoid miss-application, and it is not whether or not we can kill pigweed. My biggest concern is that only one technology will emerge and that it will do a great job. Say, for example, Roundup Ready Xtend, and growers decide that it kills pigweed and that this is all we need. With no tank-mixes or PREs we will not be doing anything to prevent grass resistance and we will be relying on only one herbicide, dicamba, for pigweed and other glyphosate-resistant weeds. This would put us on a course for the development of new resistant weeds, especially grasses, instead of on the path of preventing resistance forever by proper use of these new tools.
I am not going to lay it all on the farmers either, the chemical companies are suing each other right and left right now over the rights to stack and sell these traits. I am doubtful that resistance management is part of those conversations, but I sincerely hope it is.