David Mortensen, Ph.D. interviewed by: Chris Walters
David Mortensen, Ph.D., is a professor of weed ecology at Penn State. Back in early 2012 he led a team of co-authors who produced a paper called “Navigating a Critical Juncture in Sustainable Weed Management.” The equivalent of an agricultural bombshell, it delivered unhappy news about the consequences of engineering crops to withstand more than one pesticide. Noting the remarkable ability of weeds to evolve resistance strategies, Mortensen and his co-authors predicted ecological disaster if crops engineered to permit the return of 2,4-D and dicamba are put into circulation. The article’s predictions of exponentially rising auxinic herbicide use were shocking until it emerged that the USDA’s estimates were even higher. Over two years later, as biotechnology’s latest assault draws closer to final regulatory approval or refusal, it seemed like a good idea to check in with Mortensen. Author of dozens of research papers, he is a veteran of decades working in fields alongside farmers in Iowa, Maryland, and many states in between.
ACRES U.S.A. What is the crux of the issue here?
DAVID MORTENSEN. This new technology that’s going to “save” herbicide- resistant crops — that is, the new stacked-trait herbicide-resistant crops — in my view is going in exactly the wrong direction. It’s going in the wrong direction for a number of reasons, not least of which is that if we adopt them we are going to double or triple herbicide use on our major commodity crops, corn and soybean, with significant increases in use on cotton. We tried to be conservative and careful in our Critical Juncture paper with that estimate of doubling and tripling herbicide use. We spent months debating that amongst the co-authors. Thus it’s intriguing for me to read in the USDA’s own assessment that we will increase use of auxinic herbicides four to seven-fold if we approve these new crops, as the USDA seems to be leaning toward doing. I find it bordering on maddening to think that’s an acceptable trajectory to put ourselves on. It goes against everything I’ve worked on for the past 30 years. Continue Reading →