On the surface, applying pesticides on crops seems simple. Farmers want to:
Kill pests.
Keep the pesticide in the field with the pests they’re trying to kill.
Technology has made it much easier to do this today than when Justin Johnson became a commercial pesticide applicator nearly 20 years ago.
“Everything – from sprayer engineering to nozzles to rate controllers – has seen an upgrade,” says Johnson, an AgLogic dispatch coordinator with Goldstar FS, Cambridge, Illinois.
Glitz-and-glitter technology, though, can mask the basics for making optimal chemical applications that don’t stray into neighboring crop fields, orchards, or rural homes. Now is an excellent time to prep sprayers and form a spray-application strategy for 2018.
“Just take the time now to look at the plumbing of your machine, whether you are new to it or if you have been running it for a while,” says Jeff Burke, plant manager for Goldstar FS at Cambridge. “Look for ways you can make it run easier in the season.”
Below, you’ll find 19 tips from Johnson, Burke, and Jim Reiss, senior vice president for product development at Precision Laboratories, that will help make this year your best spraying season yet.
1. Detect Chemical Hide-and-Seek
Cleaning sprayer tanks with rinse water and cleaner is key. Cleanout is also a must for the following:
Hoses and sprayer booms: “Check for chemical hiding in the hoses’ swales,” says Justin Johnson (pictured at right).
End caps: These can be dead spots where chemical hides during a sprayer rinse. “Flush regularly at the end of the day, whether you’ve been over 10 or 2,000 acres, says Johnson.
Fencerow nozzles: “They’re often forgotten,” Johnson says. Chemical often hangs up in the component’s strainer. Make sure to drop the screen as well as the boom screen during cleaning, he adds.
2. ½ Teaspoon Of Trouble
Pro applicators and farmers don’t like hitchhikers any more than travelers do on a busy highway. Yet, that’s what can happen if a previously applied chemical lingers in a sprayer due to improper cleanout.
Just a dab of chemical can cause a whole lot of trouble. In the case of dicamba, 3 milliliters of formulated product – just a bit more than ½ teaspoon – can contaminate 1,000 gallons of water in a sprayer, says Mike Owen, Iowa State University Extension weed specialist.
Off-target dicamba movement in 2017 in his area wasn’t so much due to volatility, wind, or temperature inversions, says Brent Johnson, GoldStar FS operations manager in Cambridge.
“It was sprayer contamination that got lots of applicators into trouble,” he says.
3. Get Zippy With Zip Ties
Spray hoses need flexibility to revolve around the boom. The flip side is that flexibility causes low spots and swales in hoses that chemical can hide in.
It’s here that low-tech can complement high-tech sprayers. “Zip ties can be your best friend when it comes to tying hoses to the boom,” says Justin Johnson. “Make sure everything is tied up where it needs to be.
“Some swales are unavoidable,” he adds. “But also try and have the sprayer as level as possible and downhill, if possible, when flushing the sprayer.” The resulting gravity will help drain chemical, he points out.
4. Go Deep Undercover ...
Under your sprayer, that is.
“One of the first things I like to do is drain the belly system (under the sprayer),” says Jeff Burke (pictured at right). “I run the machine as empty as possible. Then, I open up the reload lines. All the product needs to come out so you aren’t diluting the clean water or the tank cleaner that you add to the sprayer.”
Burke runs clean water, and tank cleaner runs all the way through the unit’s plumbing – from the tank to the booms.
“Then I drain it again,” he says. “I open up all the valves, the sparger, the reloads, and the top rinse. I make sure the pressure relief line coming off the pump that goes to the top of the tank has clean water coming out of it. With all those little lines, it doesn’t take much chemical to carry into the next field and result in an off-target application.”
5. Rinse and Repeat
Unsure if chemical has exited the sprayer during a rinse? Flush it again. “It’s easier to do it before you start instead of spraying all day and having a bigger issue down the road,” says Jeff Burke.
6. Give Lonesome Lines Love
“Think about those lines that you don’t use all the time, whether it be the top rinse line, the recirculation line, or the inductor line,” says Jeff Burke. “When you use those lines, always flush them out during the machine flush.”
7. Avoid Aggravation with Agitation
Iowa State University research recommends allowing 15 minutes with agitation for each tank rinse and at least one minute for lines and other plumbing during each spray rinse.
Remember, though, that herbicides in a suspension concentrate (SC) formulation like Callisto and Corvus can settle out after 45 minutes, says Jim Reiss (pictured at right). Thus, agitation should occur even if a sprayer is shut down during the day for a short time, he says.
8. Monitor Hoses
Over time, dicamba can soak into hoses and eventually contaminate future non-dicamba applications, says Jim Reiss. Emulsifiable concentrate (EC) formulations of 2,4-D and Select can actually eat through hoses if sufficient concentrations build up. Preventive maintenance through hose replacement can spare applicator downtime in the field during spray season, says Reiss.
9. Induct with Inductors
Sprayer inductors are for just that – inducting.
“People get in trouble when they put in more than one herbicide at a time,” says Jim Reiss. “Mixing chemicals causes nasty compatibility issues. Invariably, the (incompatible) mix will transfer from the inductor to the sprayer and plug strainers, screens, and nozzles. So, use them to funnel only one product at a time and in the proper sequence.”
10. Arm Your Nozzle Arsenal
“You used to be able to use one nozzle to do most spraying,” says Jim Reiss.
No more. More and more labels now mandate nozzle selection.
“If you spray a dicamba product, choices include TTI, ULD, or TDXL nozzles to make extremely coarse or ultracoarse droplets. If you use that same nozzle with straight glyphosate, it won’t work well. So, as you deploy different tools to manage resistant weeds, most sprayers have three, four, maybe five nozzles to maximize performance on every chemical,” he says.
11. One Moon, Two Orbits
It’s not uncommon for a tankmix to contain two different chemicals that require two different nozzles. What do you do?
You have to ask yourself what you are going after,” says Jeff Burke. “Glyphosate works in a wide range of nozzles, but Cobra doesn’t. If you’re applying both products in a mix, select the nozzle that works best for Cobra.”
12. The Right Mix
Farmers or chemical applicators these days must feel like master chefs, considering all the components that go into spray tanks and through sprayer lines and booms. To complicate life, they must be added in the right mixing sequence.
“Mixing order is critical in preventing compatibility problems,” says Jim Reiss. “Many times, it’s not super complicated tankmixes that cause problems. It’s some of the simple ones.
“I think of situations where producers run Roundup, crop oil, ammonium sulfate, 2,4-D ester, and atrazine, which is a pretty common burndown,” he says. “If you add the atrazine before 2,4-D ester, you will be fine. If you add the 2,4-D ester before atrazine, you will have a cottage cheese mess that floats to the top of the tank. If you don’t catch it, you will spend a day unplugging your sprayer, if you’re lucky. Unplugging your sprayer could even take longer.”
13. No More Missing Spoons
Besides housing canned foods, Mason jars have often done double duty by being used to test chemical mixing order. Ditto for occasional measuring and stirring spoons borrowed from farm kitchens.
No more. These days, compatibility kits can take the guesswork out of mixing. An example is the one from Precision Laboratories. The kit contains instructions, three 100-milliliter containers, and pipettes with ¼-milliliter markings for accurately re-creating the tankmix. “They can give you a good idea if mixing sequence is correct, or if the mix will separate and create a precipitate like cottage cheese that plugs sprayer lines and nozzles,” says Jim Reiss.
Mixing apps are available to guide you through mixing order. “We have a free app called MixTank that you can download from the app store,” says Reiss. “It can sequence proper mixing order, create and save mix recipes, and even create spray logs. But a good double-check is still the compatibility test kit.”
14. Avoid Inversions
Applicators can’t control everything in a field, but spraying during temperature inversions is one that can be avoided, says Jim Reiss.
Temperature inversions occur when air patterns flip-flop. During daytime, warm air rises when sunlight hits the ground. When cool air above hits the warm air, wind results. This keys air circulation.
As evening approaches, cool air moves to the bottom while warm air migrates to the top. This stable environment traps any pesticide particles in a suspended air mass that can move little or miles away. That’s why 2018 federal labels for dicamba formulations labeled for dicamba-tolerant soybeans limit applications between sunrise and sunset.
15. How to Sense Inversions
Fog is a visual indicator of a temperature inversion.
Some other senses can detect inversions, too. Ever smelled something, such as distant burning grass, that cannot be seen? That can be an inversion, says Jim Reiss. Ditto for a train whistle or siren that isn’t normally heard. It’s even possible to feel an inversion. “When there is no wind, it is highly likely you’re in an inversion,” he says.
Thus, think twice about applying chemical if any of your senses detect these conditions, he advises.
16. Inversion Detector
Technology is also getting into the inversion-detection business.
This spring, Innoquest is launching its SpotOn Inversion Tester. Retailing at $375, this tool displays whether or not an inversion exists, with intensity shown in degrees based on temperature measurements taken at 1- and 3-meter heights.
17. Speed Kills
Tools like rate controllers automatically adjust pressure to match sprayer speeds. However, droplets get smaller with increased pressure going through a fixed orifice.
“You still have to watch your speed,” says Justin Johnson. “Speed kills.”
When a sprayer speeds up, the pressure has to increase to maintain the nozzle pattern. “If you go too fast, you can overrun the pattern,” he says. “Just slow down.”
18. Don’t Skimp on Water
To get by with fewer tanks and cut refilling time, applicators will often decrease chemical carrier volume from 20 gallons per acre down to 10, says Jim Reiss.
“Sometimes that works; other times it doesn’t,” he says. “Liberty is one where it doesn’t work.”
Liberty’s label requires a minimum of 15 gallons per acre, with 20 gallons per acre of water required for dense weed canopies.
19. Read the Label
Do this. Really do it. It can save lots of headaches.
Jim Reiss learned this as a newbie in the chemical business. Back in 1981, he was applying a soybean herbicide in east-central Illinois. The mix prescription called for 4 ounces per acre of a drift-reduction agent.
“I figured if 4 ounces was good, 8 ounces was better,” he says. “I added 8 ounces, and the chemical started coming out of the sprayer the thickness of pencil stems.”
Labels aren’t light reading. Still, a few hours spent reviewing them can save aggravation down the road.
