Battling superweeds with a lower volume of chemicals

Seed Daily: They pop up in farm fields across 22 states, and they've been called the single largest threat to production agriculture that farmers have ever seen. They are "superweeds" - undesirable plants that can tolerate multiple herbicides, including the popular gylphosate, also known as RoundUp - and they cost time and money because the only real solution is for farmers to plow them out of the field before they suffocate corn, soybeans or cotton.

Now, thanks to the work of researchers at Dow AgroSciences, LLC, who have been collaborating with a University of Missouri researcher, a new weapon may be on the horizon to eliminate superweeds. Zhanyuan Zhang, a research associate professor of plant sciences and director of the MU Plant Transformation Core facility, partnered with research scientists at Dow AgroSciences, LLC, to engineer soybean plants that can tolerate an alternative herbicide that may help slow the spread of superweeds, such as tall waterhemp.

According to an article in the New York Times, farmers considered RoundUp a "miracle chemical" when it was introduced because it killed a wide variety of weeds, is safe to work with, and broke down quickly, reducing environmental impact. However, weeds quickly evolved to survive gylphosate, and that threatened to reverse an agricultural advance known as minimum-till farming.

…Using a massive genetic database and a bioinformatic approach, Dow AgroSciences researchers identified two bacterial enzymes that, when transformed into plants, conferred resistance to an herbicide called "2,4-D," commonly used in controlling dandelions.…"Unlike glyphosate, which targets amino acid synthesis, 2,4-D is a hormone regulator. Because it has a different mode of action, 2,4-D is an ideal herbicide to deal with glyphosate-resistant weeds," said Zhang, who managed the soybean transformation portion of the study and contributed to some data analysis....

Conyza canadensis on the sidewalk in in Bonn-Beuel. Shot by Michael Becker, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license