Spray drift prevention not difficult I have had a lot of requests from county Extension agents this winter to comment about drift prevention. Let me first say that I am not our real expert in that area. Dr. Dennis Gardisser, our Extension ag engineer, is. Dennis is internationally recognized as being one of the very best. If you are a farmer, private applicator or commercial aerial or ground applicator and any of my comments here spark an interest or question, get in touch with Dennis for some expert help.
We have one major rice herbicide in the court system now because we have not kept it on the target. My phone also rang off the wall last spring with calls about drift. We have to get better.
Drift prevention is not rocket science. It is primarily proper equipment setup, common sense and good judgment. All I will say about equipment setup is that tremendous advances have been made in both aircraft and ground sprayers.
On ground sprayers, if you aren't using the latest in drift control nozzle tips, you are way behind. Almost every major spray tip company has an air induction-type tip that can make a tremendous difference in droplet size and drift. This technology is not expensive. If you don't have it, you need it!
Some have said the large droplets from these tips reduce postemergence herbicide efficacy. Most studies are proving this wrong. I am running them exclusively. Keep in mind they don't eliminate drift. You can't go spray in a 20- to 30-mph wind. However, you combine this technology with common sense and you will keep the herbicide where it is supposed to go.
With aircraft, I do not have a clue what the proper setup is, but Dennis does. I'm sure every operator thinks his is best. However, I do know that sometimes I see aircraft spraying and the spray is going straight to the ground and sometimes I see one producing a lot of fines and large wingtip swirls. I routinely see both.
Last season I had an aerial applicator do some rather sensitive herbicide work for me. As we were doing it, I marveled at the lack of swirls and how the herbicide appeared to be going straight to the ground. Subsequent drift card analysis and later inspections of off target vegetation proved this correct.
Later the same day I observed a like aircraft spraying and thought it was the same operator. However, the aircraft was producing large swirls and leaving a large amount of spray hanging in the air and moving across the field. Thinking maybe the operator had changed setup for a different type of application, I called and asked what they had changed from that morning to make that type of difference.
His response was, "All of mine are in the hanger. It is too windy to spray."
This isn't meant to be a blessing of one anonymous guy and a slamming of the other. However, there was a huge difference in the way the spray was behaving between two similar aircraft and also a difference between what one operator felt was unacceptable conditions and another did not.
Next week I will continue here.