Preventing Spray Drift

Randy: Hi. We are here today to talk a little bit about spray drift and some of the equipment issues. I know, Joe, when I’m out in the field doing meetings and stuff, one of the things that always comes up is spray drift.
Joe: It’s a big deal, especially with a lot of the growth regulator type herbicides, 2,4-D, dicamba, drift is a big concern.
Randy: Yeah, and I know a lot of times we’re just saying, “Well, its the wind” or maybe it’s “Someone else is causing the drift.” But in some cases it can be something just as small as just having the right nozzle tip and having it set up correctly.
Joe: Yes, nozzle selection is a big deal especially in drift production situations.
Randy: So basically what we have right here on our spray table, and I’ll turn it on, is we have some 04 nozzles, this is nothing but an extended range nozzle. And if we put the strobe light on you can see really small droplets in there and we all know what’s going to, or what could potentially happen to those.
Joe: I know there’s a lot of small fines coming off the end of that pattern there.
Randy: And if we just put a … We’ve got a fan set up, we can just put a small little breeze on this, if you want to go ahead and turn that on. This is not a strong breeze and you can start to see some of those fines moving around a little bit on the bottom of the pattern. Probably about 3 1/2 to 4 mile an hour breeze on this pattern right now and it’s starting to, the droplets are starting to move.
Joe: So the higher you get that boom up too the more you are going to see those fines start to move away from your target site.
Randy: Definitely. Excellent point. I you look up at this part of the pattern up here, you know, we are starting to see some larger droplets but the smaller ones really show up down at the bottom of the pattern. You have to have your boom high enough for the, to get the correct overlap between your nozzles but if you’ve got it any higher than that you’re just exposing those droplets to a greater chance of drift. So we can take from that nozzle and move straight into a Turbo Tee nozzle that’s going to create a little bit bigger droplet size for us and we can see that, especially up at the top part of the pattern, we see a lot larger droplet size.
Joe: This is a little bit wider pattern too. A hundred and ten degree but you’re going to see a little bit of smaller droplets there. But this will allow you to keep the boom closer to the ground as well.
Randy: So we’re looking at this and again you see down near the bottom, again with that wind on it still, a lot larger droplets near the bottom. And I think as we look at a lot of our labels right now, they’ll specify what size of droplets that you want to use with that herbicide.
Joe: Yeah, your pre-emergents type applications where coverage isn’t quite as important, bigger droplets there work fine. Post-emergents applications depends a little bit on the herbicide or other pesticide you are using, depending on how big of a deal coverage needs to be.
Randy: So this is where you really need to know your sprayer book that you’ll get, whether it’s a Delevan, a Teejet, or a HighPro, whatever it might be, you look at that sprayer book and it will tell you what type of droplet that nozzle will create. Whether it’s a medium, a coarse, or a very coarse droplet or a fine droplet and then again some of our labels will specify that it requires a certain droplet size. There’s a air induction nozzle, and again it’s a little bit, still a hundred and ten degree but it’s a little closer to the target because it’s longer but the droplet size on this, and again with that slight little breeze coming across is, it’s not moving much at all.
Joe: It really holds that pattern. Even the further you get away from that nozzle, it really holds tight there.
Randy: Well defined pattern coming all the way down. Again it’s a little different enviornment. All of these again are 04 nozzles. One thing we’re not changing on these nozzles is the pressure. We’re showing them all the same pressure but that particular nozzle can run at a higher pressure, as well as the Turbo Tee if you want to run it at the higher pressures. And the last thing we have is the Hypro Air Guard nozzle, it’s just a little different version of the air induction nozzle. It’s going to give a little bit wider droplets [inaudible 00:04:22] but you can still see some fines in there so it’s not as large of droplets as the straight air induction. But a little bit different probably than the Turbo Tee.
Joe: But then again you would want to choose that nozzle tip based on the application you’re looking for, whether it’s an insecticide or fungicide where coverage is crucial or whether it’s a herbicide, pre-emergents maybe where droplet size isn’t quite as important.
Randy: Exactly. The nozzles we’re looking at are probably, you know anywhere, depending on where you buy them $5.00 to $10.00 each. So having the correct nozzles for the job that you want to accomplish is important. If you are trying to get that canopy penetration, like I said for a fungicide in soybeans or something, or peanuts then it’s not turn the pressure up really high to get it down in there, it’s select the correct droplet or select the correct nozzle and get that set up right and run enough volume to get it down in there. I guess the take-home message that we have today is know what you need as far as nozzles are concerned.
Joe: Choose the tip for the appropriate application that you’re going to make.