Eight Keys To Managing Spray Drift

Spray DriftIf you ask any custom applicator what their top five concerns are when doing their jobs, chances are managing spray drift will be mentioned. The consequences of this are potentially severe, with regulatory fines and/or customer damage claims easily costing several thousands of dollars (if not more).

In fact, according to Bruce Senst, director of Agrisolutions adjuvants for WinField Solutions, Shoreview, MN, the potential for spray drift keeps many segments of the agricultural community awake at night. “There are plenty of things that worry your average grower or ag retailer,” says Senst. “But when it comes right down to it, everyone is concerned as all get out about spray drift and its impact on their livelihood.”

Complicating the spray drift issue in recent years is the increasing spread of herbicide-resistant weeds. Based upon the best estimates, approximately 60 million acres of U.S. farmland were infested with herbicide-resistant weeds in 2012, with portions of the Mid-South region particularly hard hit. This has increased the likelihood that applicators will need to use several different crop protection products than they did in previous years.

“Let’s face it — we are coming out of an era where you could use one product technology, glyphosate, to manage most of your application needs,” says Damon Palmer, U.S. commercial leader for the Enlist Weed Control System at Dow AgroSciences, Indianapolis, IN. “But now, to achieve this same level of control, applicators are having to mix other crop protection products into their programs, and that has sparked a lot of questions about how do you manage spray drift when you are using multiple herbicides?”

Furthermore, several crop protection manufacturers such as Dow AgroSciences and Monsanto Co., St. Louis, MO, are readying new herbicide-resistant cropping systems for the marketplace in the coming years. This has the potential to see increased application usage for products such as 2,4-D and dicamba, which in turn, will increase the pressure on applicators to more accurately manage spray drift.

Best Equipment Practices

With these factors in mind, CropLife® magazine spoke with Dr. Robert Wolf, Wolf Consulting & Research, LLC, Mahomet, IL. The past few years, Wolf has spent much of his time conducting the On Target Application Academy (with cooperation from TeeJet Technologies and BASF).

“In my training, I have a list of drift management strategies that I work from,” says Wolf. “I probably trained nearly 3,000-plus applicators in 2012.” In essence, he adds, there are eight best management practices applicators should follow to manage spray drift.

No. 1: Nozzle Selection. “This is the strategy that has been used for years to reduce spray drift,” says Wolf. “However, with today’s nozzle options, there are many more choices from multiple nozzle manufacturers that applicators have. The challenge is how best to set the sprayer parameters — basically speed and pressure — so that while minimizing drift crop protection efficacy is not sacrificed. In recent years, that has been an issue.”

Michelle Vigna, assistant launch manager, Roundup Ready Xtend System for Monsanto, agrees that nozzle selection is one of the keys to preventing spray drift. “Here at Monsanto as we introduce the Roundup Ready Xtend system, we are focusing a lot of attention on proper nozzle selection,” says Vigna. “For our users to achieve the best on-target application, we recommend they use air induction nozzles.”

No. 2: Use lower pressures. This is another widely held method for managing spray drift. However, according to Wolf, this practice might require some adjustment to be effective in today’s application world.

“Forever, the advice to applicators for reducing spray drift was to ‘use a lower pressure,’ which result in larger droplets,” he says. “This was the No. 1 educational point for drift minimization.”

Some of these recommendations have changed, however, as nozzle technology has improved. “Now we have nozzles designed to reduce drift while at the same time doing so at higher pressure,” says Wolf. “The higher pressure is needed to help produce a smaller droplet size increasing the coverage potential on the targeted pest — typically a herbicide on a weed. This fact was not really known when the designs were first introduced.”

As Wolf explains, the design of drift reducing nozzles is to create a pressure drop and, in some cases, introduce air via a Venturi into the mix. Both of these will produce larger droplets.

“When using a drift reducing nozzle at a low pressure, i.e., 30 to 40 psi, it is quite possible, because of the design, that the outlet pressure has been reduced in a ratio of 3:1 or 4:1,” says Wolf. “This can result in an exit psi of 10 to 20 psi. That is too low to maintain a quality pattern or to create droplets for adequate coverage. Thus, the recommendation is to use these Venturi designs — commonly referred to air induction — at pressures ranging from 50 to 80 or higher psi. Even at that high pressure, the amount of drift is less than previous designs at lower pressures.”

No. 3: Increasing flow rates. This is been done by applicators to achieve higher application volumes. According to Wolf, this has been a common practice to reduce spray drift for years. “In general, bigger orifices produce larger droplets,” he says.

However, geography can impact how this practice plays out to manage drift for some applicators. “My years in Kansas provide a different perspective on this issue,” says Wolf. “For the most part, applicators in the Plains states tend to use less water in the spray mix. This is probably a result of the environment . . . less water available for most all things in agriculture and wanting to spray more acres on a tank load of mix. The problem is that when using less water, a smaller-sized nozzle is needed, resulting in smaller, more drift-prone spray droplets. Combine that with modern sprayers capable of higher application speeds — translated to higher pressures — and more drift is possible.”

No. 4: Lower the boom height. Again, cautions Wolf, what applicators have traditionally done in this area may not still be the best way to manage spray drift. “Today, some applicators do not understand that the height of the boom above the target is based on nozzle spacing and overlap requirements to achieve a uniform application across the boom,” he says. “The ‘rule of thumb’ for boom height in the industry is 1:1. That would mean a 20-inch nozzle spacing would require a 20-inch boom height above the target, either the soil in a pre-emergence application or the weed or crop canopy in a foliar scenario.”

Instead, Wolf recommends applicators get their boom heights down to 24 inches. “In my opinion, that will go a long way toward reducing drift,” he says. “I have a slogan for this — lowering the boom on spray drift.”

Other Considerations

No. 5: Watch application speeds. “Most all applicators are using electronics to apply crop protection products,” he points out. “The purpose of a rate controller is to make the application volume uniform. What most do not realize is the speed change will also affect the spray pressure. Higher speeds require higher pressure to deliver the correct volume; lower speeds the opposite. Thus, as applicators are making speed changes, they are impacting the droplet size.”

In his training exercises, Wolf cites this example to illustrate this point: An applicator has set the sprayer up to use a #4 nozzle going 12 mph at 40 psi to deliver 10 gallons per acre. A storm is brewing in the West, so the applicator decides to speed up to 15 mph. A 3 mph speed increase will require the pressure to increase to over 60 psi in order to deliver the same volume through the #4 nozzle. As the storm gets closer, they speed up a second time to 18 mph. Now the pressure will need to be 90 psi to deliver the same volume, which obviously increases the potential for spray drift to occur.

“My educational point is to drive at the speed you calibrated for,” he says. “Also, the rule applicators should remember is that to double the flow from a given orifice size, they will need to increase the pressure four-fold. As an example: If the applicator is going 8 mph at 30 psi and changes to 16 mph, this will cause the pressure to increase to 120 psi.”

No. 6: Avoid adverse weather conditions. According to Wolf, these would include high winds, calm air or inversions. “This is an area that applicators have no control over,” he says. “But the best option is still to choose not to spray when environmental conditions are not favorable.”

No. 7: Use buffer zones. As Wolf points out, the increase in different herbicides, coupled with label requirements, in the near future will make these more important for applicators to achieve proper on-target work. However, size could be an issue.

“The size of the buffer zone will be the problem,” he says. “The concern today is that ground applicators might not consider not spraying next to a sensitive area by leaving a buffer zone. Instead, they might choose to come back on a day when the wind is blowing away from the sensitivity to spray.”

No. 8: Consider other technologies to reduce drift potential. According to Wolf, this could include the use of shields, air-assist or pulse-width modulation or drift reduction additives such as adjuvants.

In summation, Wolf reminds applicators that all of these practices are good at reducing the potential for spray drift, but only if they aren’t chosen selectively. “A good drift management plan will include multiple strategies,” he concludes. “One item from this list will not be sufficient alone. One practice alone does not make for a good plan.”

Topics: , ,

Leave a Reply

Management Stories

ManagementThe Latest Dow-DuPont Rumor, Product of the Year Voting Update, and CropLife 100 Preview
October 20, 2016
CropLife Editor Eric Sfiligoj shares a new rumor about the Dow-DuPont merger and updates on two CropLife-driven programs, the CropLife Read More
ManagementHarvest and Crop Price Updates; EPA and Crop Protection Reviews
October 13, 2016
Glyphosate and atrazine get public comment support from ARA as each is reviewed by EPA, and the latest on the Read More
ManagementVision Conference Preview, Monsanto Earnings, and Product of the Year Voting
October 7, 2016
Editors Paul Schrimpf and Eric Sfiligoj talk about the upcoming PrecisionAg Vision meeting in Arizona, Monsanto’s latest revenue numbers, and Read More
EmployeesOABA Program Develops Future Generation Of Agribusiness Leaders
September 29, 2016
The Ohio AgriBusiness Association will select up to 25 promising leaders to participate in a leadership enhancement program early next Read More
Trending Articles
AGCO RG700 cab
OpinionRoadblocks To Precision Ag Innovation
October 5, 2016
On August 29, I got to preside over the PrecisionAg Innovation Series event, “Game-Changing Advances in Precision Farming Technology,” developed Read More
J.C. Ramsdell containment system
EquipmentClear Opportunity In The Tank Market
October 4, 2016
Crop prices may be down, but steel prices are too — and that’s good news for retailers looking to add some Read More
WinField booth Farm Progress
Special ReportsTalking Weed Management Strategies At Farm Progress 2016
October 2, 2016
The annual Farm Progress Show — this year staged in Boone, IA — is always a great place to catch Read More
Corn Field
Eric SfiligojFacing Ag Industry Challenges
September 26, 2016
At the 2016 annual Mid America CropLife Association (MACA) meeting in September, a pair of crop protection company representatives discussed Read More
Bayer Monsanto
Crop InputsBayer-Monsanto Mega-Merger: 6 Things You Need To Know
September 14, 2016
Mega mergers have become almost routine in the agricultural industry. Right on the heels of Monday’s news that fertilizer giants Potash Read More
Potash Corp Agrium
Crop InputsAgrium, Potash Corp To Merge To Create $36 Billion Company
September 12, 2016
Canada’s Agrium Inc. and Potash Corp of Saskatchewan Inc. have agreed to combine in a deal that would create a Read More
Latest News
Kennebec Grain terminal
CropLife 100Wheat Growers Kennebec Facility Loads First Rail Cars
October 21, 2016
In a season of firsts for Wheat Growers’ Kennebec Grain Terminal, the first 115-car unit train was loaded with soybeans Read More
ManagementThe Latest Dow-DuPont Rumor, Product of the Year Voting…
October 20, 2016
CropLife Editor Eric Sfiligoj shares a new rumor about the Dow-DuPont merger and updates on two CropLife-driven programs, the CropLife Read More
Soybean Closeup
FungicidesFMC Begins Registration Process For New Fungicide Activ…
October 19, 2016
FMC Agricultural Solutions has begun the joint U.S. EPA and Canadian Pest Management Regulatory Agency registration process for bixafen, a new Read More
Soil Young Corn
Industry NewsAgribusiness Search Firm Appoints New Managing Partner
October 18, 2016
Morris Bixby Group, a leading agribusiness search firm providing the highest quality professional recruiting and career advancement services since 2000, Read More
Wheat Field North Dakota
FertilizerUnited Suppliers Acquires Kansas Fertilizer Business
October 17, 2016
United Suppliers, Inc. has purchased the assets of Evans Enterprises, LLC, an ammonium chloride fertilizer business based in Olathe, KS. Read More
Corn Field
Industry NewsFMC Launches New Operations In Argentina, Exits Joint V…
October 17, 2016
FMC Corp. has exited its joint venture with Ruralco Soluciones S.A. FMC has launched new commercial operations, FMC Quimica S.A., Read More
Dow AgroSciences
InsecticidesRenewed Registration Issued For Products Containing Sul…
October 17, 2016
On October 14, 2016, the U.S. EPA re-established the registration of products containing sulfoxaflor (Isoclast Active), including Transform WG, Closer Read More
Eric SfiligojThe Whys Of Agriculture
October 17, 2016
During 2016, there have been myriad challenges facing the whole agricultural industry. Such wide ranging issues as water protection, sustainable Read More
Young Corn Field
FertilizerImproved Phosphorus Management Essential To Feeding Wor…
October 14, 2016
With a global population expected to reach 9 billion people by 2050, improved management of key essential nutrients such as Read More
ManagementHarvest and Crop Price Updates; EPA and Crop Protection…
October 13, 2016
Glyphosate and atrazine get public comment support from ARA as each is reviewed by EPA, and the latest on the Read More
Matt Hopkins15 Twitter Accounts Every Ag Professional Must Follow
October 13, 2016
What do singer Katy Perry and the President of the United States have in common? They are two of the Read More
Corn Field
Industry NewsArysta LifeScience Adds Two Key Account Managers
October 13, 2016
Arysta LifeScience North America recently announced the addition of two key account managers: Doug Hoberty and Rob Wier. Hoberty and Read More
EquipmentDeere Announces Development Deal with Scherer Design
October 12, 2016
Deere & Co. announces a joint development agreement with Scherer Design Engineering, Inc. to develop and commercialize kernel processing solutions Read More
Crop InputsMarrone Bio Innovations Celebrates 10 Years Of Innovati…
October 12, 2016
Richard Rominger, former Deputy Secretary of the USDA and former agricultural secretary of California, emceed a 10th anniversary luncheon celebration on Read More
Photo credit: The United Soybean Board/The Soybean Checkoff.
Industry NewsVive Crop Protection Closes Financing To Support Corpor…
October 11, 2016
Vive Crop Protection has announced the closing of growth financing to support 2017 commercial expansion. The financing was led by Read More
SoftwareHD Precision Analytics Launches New Mobile App For Agri…
October 11, 2016
AGSentry from HD Precision Analytics is a Software-as-a-Service (SaaS) platform that offers simple data service and actionable analytics tool. It focuses Read More
HerbicidesWeed Control And Soil Health Go Hand-in-Hand
October 10, 2016
Although many landowners may not give much thought to weed control as a soil health measure, Gared Shaffer, South Dakota Read More
Students Soybean Field
Eric Sfiligoj2016 Young Leaders Speak
October 10, 2016
One of the consistent cries in agriculture today is the need to try and connect with the younger generations, attempting Read More