Ken Schneider, from Sanger, California, offers a correction to our story about dicamba-resistant crops back in November:
"I found your editorial on dicamba resistant soybeans troubling. Your reference to volatility and drift were used interchangeably. This is not correct. In reality volatility is inherent in the product itself and the formulation. It is the propensity of a product to lift off once deposited. Drift is more of a problem with weather conditions, off target movement and application precision. If you have a product that is nonvolatile, but are sloppy in applying it, you will still get damage to neighbors sensitive crops, often for long distances."
Ken, we did misuse the terms in our story, and we apologize. We are all about to get schooled on volatility thanks to the rapid adoption of dicamba-resistant soybeans to combat some serious weed problems. We will be talking about this often, but I want to lift up one point to farmers who remember using dicamba on corn, and wonder what all the fuss is about.
Back before GMO corn, dicamba was a popular broadleaf weed control herbicide, and even then we noticed its unpredictable behavior in the field. But even though we had the same problems with drift and volatility, we rarely saw the kind of crop damage that happened in the southern Corn Belt last year.
The big difference, I belatedly realized, was when we applied the product. I remember the ideal application window was when corn was 5" high. At that time, most beans had not even emerged, since beans were usually planted after corn. Consequently, even though I had some damage to my crops and neighboring crops I never had to make good on my offer to make restitution.
Strangely, I had a field where the dicamba drift seemed to improve yields. However, today we're talking about applying dicamba much later in the season, when soybean yields can be seriously compromised by drift and volatility.
My point is that some of us need to rethink our attitude about dicamba application because of our memories can be singularly unhelpful. We need to pay attention to this issue, because this is not your father's dicamba problem.