Dicamba – What’s The Problem?

Screen Shot 2017-06-24 at 7.58.59 AMIn the last Farm Catch Up I talked a bit about the herbicide dicamba and noted that Arkansas regulators had already banned Monsanto’s brand Xtendimax of herbicide blend that contained the product and were considering a ban on the other one that was approved for use with Monsanto’s Xtend line of seeds, Engenia. “Procedural irregularities” prevented the Arkansas State Plant Board from passing an emergency ban on June 20, but I should have waited a couple of days because on June 23 ASPB passed a 120 day emergency order banning in-crop use of dicamba.

Someone pointed out to me that a lot of my readers aren’t in the agriculture business and may not know what the whole problem is, and that it would be a good idea to give a better explanation of what’s going on and why this is so important to so many people. So here goes

Super Weeds

That’s where it all starts, of course: super weeds, the ones that have been developing resistance to glyphosate, the active ingredient in herbicides like RoundUp. Everyone knew that as soon as glyphosate and the GM crops developed to work with it were released, weeds would begin to evolve resistance to the herbicide. That’s just the way nature works. Guidelines for usage that would help to prevent this, or at least slow it down, were developed even before the products were released for general sale. But everyone knew it was just a matter of time before “super weeds” started to pop up and spread. The fact that the guidelines and safeguards were largely ignored didn’t help much, either.

So now we’re faced with glyphosate resistant weeds that are spreading all across the country. So a new magic bullet needed to be found, and they picked dicamba.

Dicamba has been around for a long time. It was first discovered back in 1942 and has been used to control brush, legumes and cacti. It was also used along fence lines and roads to control brush. Some formulations have been used for weed control on lawns, golf courses, etc. for decades as well. It was never used on crops because it was highly toxic to commercial crops.

Dicamba has some serious issues, not the least of which is it’s tendency to drift over large areas beyond the treatment area.

Monsanto decided that dicamba was an excellent solution to the problem of weeds that were resistant to glyphosate, and developed it’s Xtend soybean plant, which could tolerate both glyphosate and dicamba. It developed a new formulation containing both glyphosate and dicamba.

Monsanto developed what was supposed to be a complete system, it’s new GM soybean coupled with the new formulation of glyphosate and dicamba. The new formulation was supposed to cure the problems dicamba had with easy volatility and wide spread drifting. The company claimed that if used according to its guidelines and with the proper equipment, the issues with the herbicide would be eliminated.

Well, there was one big problem right off the bat. Monsanto started to sell the GM seed before the government had approved the use of it’s new herbicide blend. This led some farmers to dump dicamba on their fields even though the government had not yet approved any form of dicamba for use on crops. Without the special low volatility formulation and without using the proper equipment, dicamba spread widely, damaging or destroying tens of thousands of acres of non-Xtend soybeans, it is claimed. Oh, and somebody got shot and killed over it, too. A heated argument between farmers over alleged damage to crops ended up with someone getting killed.

Well, the new formulation of herbicide is now approved, and things don’t seem to be doing much better for either Monsanto or the other company that makes the new herbicide. There are reports popping up all over the place that the new herbicide, even when used exactly according to the recommendations, is drifting all over the place. In one case it’s alleged that it drifted more than a mile and a half. In Arkansas alone there have been around 250 reports of damage caused by herbicide drift.

As noted at the beginning of this, Arkansas has already instituted a ban on Monsanto’s formula, and the government is now issuing an outright ban on all dicamba use on cropland because of all the damage reports.

The whole thing is a real mess at the moment. Lots of finger pointing, lots of accusations, even conspiracy theories. I heard one farmer claim that the drift problem is deliberate. He claims that the company knew this was going to happen, wanted it to happen, because it would force farmers to buy the GM seed from the company because even if you didn’t use the new herbicide, drift from neighboring farms that did would wipe out your crop unless you used their beans.

I haven’t seen reports from other states about this situation. If I do I’ll pass them along. Right now it’s a huge mess and the only people who are going to be profiting from any of this seems to be the lawyers.


Let’s talk about herbicides. It’s almost the time of year when we’ll start seeing the spraying equipment hitting the fields around here, so let’s talk about herbicides, one in particular called dicamba. And if you read the agriculture press, you’ll be seeing articles like this one that warn of the pitfalls of using this old-but-new-again herbicide:  Caution Lights Ahead For Dicamba Use | Ag Professional. (And before you ask, yes, there are already dicamba resistant weeds out there and one experiment showed it took one type of weed only three generations to develop resistance to the herbicide. <read that article here>)

Now I should point out that dicamba has been around for a long time. It was developed back in the late 1950s and has been on the market ever since. It’s used to control broadleaf weeds and brush. What’s new about it is that Monsanto has developed a line of dicamba resistant crops such as soybeans which can tolerate the herbicide. With these crops being resistant to both glyphosate, the active ingredient in RoundUP, and dicamba, the hope is that this double dose of herbicide will help to control weeds that are resistant to glyphosate alone.

But there are, as always, problems.

The first of these is dicamba itself. It volatilizes easily, going into vapor, which then moves over large areas. It also is subject to drift while spraying. The droplets from the sprayers can drift over large areas as well. This combination of easy volatility and tendency to drift makes it troublesome to work with because it can spread over large areas, killing or damaging plants well outside of the area being treated. In order for dicamba to be used in the way Monsanto wanted, special blends and compounds had to be created to help prevent the easy volatility and drift of the product so it wouldn’t contaminate adjacent fields.

Monsanto decided to sell its Xtend seeds before the herbicide blend it was designed to work with was approved by the government. The result was that farmers who should have known better planted the seed, and then used dicamba blends that were not approved for use, and tens of thousands of acres (some estimates are in the hundreds of thousands of acres) of crops were damaged or killed by the drift from the herbicide. There are currently lawsuits going on against Monsanto claiming the company is responsible because it released the Xtend seed before the accompanying herbicide blend was available, and Monsanto should have known that some farmers would use dicamba illegally.

The new legal blend is now available, but even that isn’t going to solve the problem. There are a whole host of restrictions, requirements and warnings adorning the labels of the new herbicide. It can only be used with a particular type of sprayer nozzle, has to be applied no more than X inches above the weeds, has to be used at a certain point in the weeds’ life span, the wind can be no more than 10-15 MPH… The list goes on and on. All of the warnings and requirements indicate that this new “safer” blend isn’t all that much safer than the original form of dicamba was.

And in the long run dicamba is going to end up being just as useless in controlling weeds as glyphosate is becoming because as that article I linked to at the beginning points out, weeds will quickly become immune to it as well.

I keep wondering how much longer we can keep this up, concocting ever more toxic and complex blends of herbicides to try to control weeds, when we know that it is, at best, a temporary fix and that the weeds will eventually become immune to even that.

Meanwhile over in France the government has been trying to push things in the other direction, trying to get agriculture away from the ever increasing reliance on herbicides and pesticides. France <story here> has set a goal of cutting the use of pesticides of various types by 50% over the next ten years through the use of alternative methods of pest and weed control. How successful the program has been is a bit questionable, but studies have indicated that farms could significantly cut their use of pesticides and herbicides without a loss of income. But it would require some significant changes in farming practices.

Can we get away from this apparently never ending cycle of herbicide/pesticide resistance? We’re going to find out and in the not too distant future because the current situation simply cannot continue indefinitely.