I’ve had 5 calls in the last 6 days about orchards hit by either 2,4-D mix drift or volatization from adjacent row crop fields being burned down in preparation for planting. The most common mix has been 2,4-D, Glyphosate and Flumioxazen. The 2,4-D shows up as twisted or curled leaves, the glyphosate as thin, strappy leaves on the resulting new growth and flumioxazen burns the foliage. This is never a pleasant situation. It tends to be infuriating, nerve-wracking, and worrisome. The good news here is that most of the time, the trees grow out of the injury. If the damage is light, there may not even be any crop loss. But, there is potential for serious damage, loss to the crop, and even whole branches from the trees.

A few years ago one of our weed scientists, Dr. Erik Prostko and I implemented a study at the UGA Ponder Farm in which we directly sprayed individual trees with varying concentrations of both 2,4-D and Dicamba from low to a full rate to try and simulate various drift scenarios. Our results suggest that serious injury can occur to pecan trees receiving a drift application of 1.0% by volume dicamba or 2,4-D. This injury includes deformed foliage, dead foliage, dead limbs, and/or branches, and arrested nut development. Pecan damage resulting from off-target movement of 2,4-D and dicamba at rates ≥1% by volume has the potential to cause significant injury. Yield was not negatively affected by any of the treatments, suggesting that pecan trees can compensate for the observed injury to some extent. However, in our study we only sprayed certain limbs and not the whole tree. We saw that the 1% rate sometimes killed the individual limbs that were sprayed but the rest of the tree was fine. If an entire tree were sprayed with these high rates, the results would not be pretty.

Every drift case is different. They are almost always a wait and see scenario, which makes them more frustrating because growers are having to make decisions in real time about how much money to put into the crop before they really know if there will be a crop following a drift event. As mentioned earlier, over the nearly 20 years at which I have been doing this job, most of the time drift issues look much worse, especially early on, than they turn out to be. But, I have seen instances of severe damage.

If damage occurs, manage the crop normally until mid-late June, then evaluate the crop to see if there is enough crop there to continue normal spray and management practices or if the crop is light and you need to back off a little on the inputs. Hopefully, the crop will be fine for most cases.

If you are on the receiving end of this problem, here are some suggestions for the next steps to take:

  1. Talk calmly with the farmer who’s field the drift came from. Find out what materials were sprayed, when, and under what weather conditions. Most of the time they are willing to do what is needed to resolve the problem.
  2. Ask for their crop insurace agent so that they can be notified the event occured. It may turn out to be no loss at all but just to cover your bases, the row crop farmer’s insurance agent should be notified that the event occurred in case further steps are required.
  3. Have GA Dept of Ag pull tissue samples to test for presence of the suspected herbicides. GA Dept of Ag inspectors must pull the samples themselves in order to maintain an appropriate chain of custody to verify the presence of the chemicals on the off-target crop. Certain herbicides must be tested within a certain number of days from when the event occurred in order for the chemical residue to show up in the screening test so do this as soon as possible. Contact GA Dept of Ag by filling out the form here for drift complaints
  4. Take photos of the damage for documentation. Note whether or not flowers or catkins were burned off. If female flowers are burned off, the tree will not set another crop that will make it through to harvest this year on those terminals on which the female flowers or nuts were burned off.
  5. This is the hardest one to do but, wait. Often the foliage will look worse before it begins to look better.

Below are photos from one of the lighter cases I have seen this year. It can get much worse

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