On Target Spray Systems Spot On

By Gerald Mitchell
Originally posted at The Grapevine Magazine.

With more than a decade of experience with electrostatic sprayers under his belt, Sonoma County wine grape grower Mark Lingenfelder is one of the early adopters of the technology. He’s also one of its biggest advocates. The executive vice president of vineyards for Chalk Hill Estate uses electrostatic sprayers on virtually all of the 400 acres he manages.

Electrostatic sprayers designed and manufactured by On Target Spray Systems provide better coverage than traditional air-blast sprayers, he said, use far less water, and enable him to treat two and three times as many acres in any one day than he can with traditional spray technology. “A lot of time in spraying is wasted driving back to the shop and filling the spray rig up and mixing,” he said. “If you can reduce the number of gallons of water you use per acre and still get as good or even better coverage, you can cover that many more acres.”

Neighboring Sonoma County wine-grape grower Ted Klopp said he, too, has been able to reduce the time he spends filling his spray tank since he switched from an air-blast sprayer to an electrostatic sprayer from On Target Spray Systems, going from an average of 50 gallons of water per acre to 15 gallons.“Now my fill-up time is minimal,” Klopp said. “I’m not eating up a lot of time running back and filling up the tank every few acres.”

Ditto for Keith Roberts, senior viticulture manager for Wente Family Estates in Greenfield, California.
“If you take a conventional sprayer and you’re filling it five times in a day, and it takes a half-hour each time, that’s five times the half-hour that you lose per day,” Roberts said. “With the On Target sprayer, we fill it up in the morning, then we fill it up at lunch and it runs the rest of the day. “And as for coverage, it is doing as good as or better than the conventional sprayers, with one-quarter the amount of water,” Roberts said.

Roberts said that given the risks, he hesitates to reduce fungicide rates, particularly during the peak growing season when grapes are highly susceptible to powdery mildew and botrytis.
He has, however, been able to reduce his use of spreader. “We use so many parts per hundred gallons, so the concentration stays the same,” he said, “but we are using less spreader.”

Conversely, Don Hofer of Kiler Canyon Vineyard in Paso Robles, said he has lowered fungicide inputs considerably since switching from an air-blast to an electrostatic sprayer. “We are using 50 percent of the amount of chemicals we used to use, and we were able to reduce our sprays from six per growing season to four per growing season,” said Hofer, who purchased an On Target sprayer in June of 2013.
“Performance has been just tremendous, beyond my expectations,” he said. “It has saved us a lot of money.”

Electrostatic sprayers produced by On Target Spray Systems can best be described as the new generation of electrostatic sprayer. The technology has been around since the 1940s when automobile manufacturers began using it to paint vehicles. In the 1980s, the agricultural community began researching its use, and some versions of the technology have been available in spray systems since the early 1990s.

At its simplest form, the technology works by uti lizing the law of attraction. With tiny electrostatic charges, the system atomizes, or positively charges, droplets that are attracted to the negatively-charged, or grounded, surface of a plant.

Also, because the droplets are positively charged, they repel one another and will not collect into large droplets that can run off plant material onto the ground. Spray from an On Target sprayer emerges from the system’s patented nozzles as a mist that evenly coats the fronts, backs and undersides of plant material, forming a bond that protects plants from disease and insect pests.

Growers talk about how spray from an On Target sprayer appears to linger over crop canopies.
“It is like a fog,” Lingenfelder said. “And if the mist goes through the canopy, it makes a U-turn and goes back in.” “It just hangs there for a minute,” Klopp said. “You can almost see it working its way into the vines.” Conversely, Klopp said: “With an air-blast, ten seconds after you pass, it is on the ground or in the vine.”

Ironically, it wasn’t the savings in labor and fuel or the improved chemical performance that initially prompted Lingenfelder to purchase an electrostatic sprayer. He was looking to appease neighbors who were complaining about pesticide drift after a housing development sprang up around three sides of a 50-acre Chalk Hill vineyard. “Some of those houses come right up to the property line, and we were having negative issues with the neighbors about drift,” Lingenfelder said. “I’m not talking two or three neighbors. I’m talking more like 30. And they were really irate.”

To dispel the drift complaints, Lingenfelder began spraying at night. Then came the noise complaints.
“We were turning the tractor right next to one neighbor’s back fence, over and over,” he said. “Those air-blast sprayers make a hell of a racket. And to drive that fan and that pump and pull that 300 gallons of water, you have to run that tractor at a high RPM, so the tractor is making more noise.”
Lingenfelder’s farming practices were protected by Sonoma County right-to-farm laws, but he sought to get along with his neighbors. After talking to a neighboring farmer who owned an electrostatic sprayer, he began looking into purchasing the advanced technology.

With On Target sprayers, Lingenfelder discovered he could essentially eliminated drift and dramatically minimize noise. “We wanted to be able to tell the neighbors, ‘Look, we have done everything we possibly can to keep it as quiet as possible and keep the drift down to a minimum,’” he said.

What he discovered next surprised even himself. After treating the vineyard with the electrostatic sprayer, Lingenfelder noticed that the block, long a problem spot for mildew, was mildew free. “That was our worst spot for mildew, and when we switched over to the electrostatic sprayer, we didn’t have mildew anymore,” he said. “We bought the other two sprayers just because we liked the performance, and we were able to cover so much more ground.”

Today, because of the efficiency he attains with electrostatic sprayers, Lingenfelder is able to protect his entire acreage with just three sprayers. “With the three sprayers, it takes us about ten days to get through everything,” he said. “If we were using more gallons (of water) per acre, we wouldn’t finish it in ten days. So there would be some period during the season where we would not have coverage.
“If we were using the other technology, we would probably need at least one more tractor and one more sprayer, and that is quite an investment,” Lingenfelder said.

He also achieved his original goal. “Now, with the electrostatic sprayer, we don’t get the drift,” he said. “And it is so much quieter than an air-blast sprayer. Now the sound of the tractor engine is louder than the sprayer.”

Roberts, who manages about 900 acres of vineyards for Wente Brothers, said he has been intrigued with the electrostatic technology since it first emerged in agriculture in the early 1990s. Not until On Target came out with its advanced models, however, was he confident enough to try it. “The On Target unit was the first one that I thought was dependable enough that I wanted to try it,” he said.
“With the On Target unit you’ve got (electrostatic modules built into) individual heads,” Roberts said. “So, if you happen to lose one, it is not going to cause you a major spray-application issue. With a lot of the other units, if you lose one electrostatic module, you’ve lost the whole rig. “That was the downside, and it drove me away from the technology all those years, even though it seemed like the right thing to do,” he said.

With three years of positive experiences with the On Target sprayer under his belt, Roberts said he now is documenting exactly how much the sprayer saves in labor, fuel and other costs to help determine if it is cost effective for the company to purchase more. “It appears at this point that it makes sense (to buy more units),” he said, “but we now are just making sure the documentation supports that decision. “I do know that the On Target unit is reliable,” Roberts said. “I think it is a great tool, and we’ve definitely integrated it into our system, and we have no plans to pull it out of our system.”

Up in Selah, Washington, Tom Merkle of Zirkle Fruit Company, said he’s been using electrostatic sprayers on wine grapes for about as long as the technology has been available, enjoying, among other benefits, the low-carbon footprint the sprayers provide. “You’re definitely lowering your carbon footprint,” Merkle said, “and you’ve got less drift. You’re not just throwing a bunch of spray up in the air and hoping it goes where you want. You’re focusing that spray. The charged particles are going right to the canopy. We don’t have much drift at all.”

On Target sprayers typically cost more than conventional air-blast sprayers, but growers said the sprayers pay for themselves in a manner of a few years. “Over time, it pays for itself, for sure,” Merkle said. “It’s a time saver, a fuel saver, and a labor saver.” “When I considered the advantages we receive from it, they far outweigh the additional costs,” Hofer said. “It is saving us money with tractor time and expense, because it takes half the tractor time to cover the vineyard. “We’re now thinking that it will pay for itself in four years,” Hofer said.

Lingenfelder said he determined that with the savings the On Target Spray Systems provide in labor, fuel and other costs, he can justify the extra expense “if not in that first season, part way through the second season.”
Bryan Wallingford of Mesa Vineyard Management in Templeton, Calif., said he believes that “in a perfect situation, the technology pays for itself in as little as two years. “The technology is great and we’re promoting it throughout our company,” he said.
Wallingford said he began to look into On Target Spray Systems in the mid-2000s after being unable to achieve coverage he needed with his air-blast sprayer to control a Pacific mite outbreak. “Basically, you have to be able to cover the whole canopy,” Wallingford said, “and with the sprayer that I was using, I wasn’t able to do that.”

After purchasing an On Target sprayer, he noted: “I was able to successfully reduce the population while going from five sprays down to three sprays, and then down to one. Now, because of the coverage that I am getting throughout the year, I don’t have to worry about spraying for them at all.”

The only downside growers mentioned when interviewed about On Target Spray Systems was the extra maintenance involved in keeping the machines in peak operating condition. “With the electrostatic sprayer, you have the electronics, the nozzles, the valves that you have to take care of,” Klopp said. “It is a finer piece of equipment.” “There is a lot more technology involved in these sprayers (than air-blast sprayers),” Lingenfelder said.
Hofer also found that it takes more work to maintain the On Target sprayer than an air-blast sprayer. But, he said: “We found that as long as you follow the directions in the handbook, it is easy and simple and gives you a lot of reliability. We have never had a maintenance issue with that sprayer.”

Asked to name the number one benefit On Target Spray Systems provide his operation, Hofer said it comes down to coverage. “The On Target sprayer saves on tractor time,” Hofer said, “diesel fuel, wear-and-tear on the tractor, personnel time and, most importantly for us, we get the great coverage that allows me to go to sleep the night before I start spraying fully realizing that I will get excellent coverage.”

“With the labor saving, fuel savings, and, in some cases, the chemical savings, I’m sold on it,” Wallingford said. “I’m sold on electrostatic in general. And On Target is the best that I’ve seen.”

Product Review: Electrostatic Sprayers

Compact, affordable and targeted spray rigs for high density growers

Article taken from Wine Business Monthly, by Bill Pregler.

WITH EARLY DESIGN flaws behind us, today’s electrostatic vineyard sprayers are finally delivering what was originally promised: incredibly precise chemical disposition.

Thanks to precise delivery, growers are experiencing substantial savings in water, chemicals and labor. Some say it is becoming difficult to justify many traditional “air-blast” sprayers.

The original designs date back to the early 1970s, but many experienced electrical problems. “Adoption was slow because of the difficulty of demonstrating and continuously verifying the electrostatic charge was being applied to the droplets,” said retiring Dr. Robert Wample, chair and director of Fresno State’s Department of Viticulture and Enology. “But recently the technology has come a long way.”

Wample continued, “It was also difficult to see the material being applied when compared to traditional air-blast. There the operator can see the blast of solution being applied, but also onto the ground, into the air and other non-target areas.”

Growers today who follow electrostatic rigs will see the difference. Comparing a dry leaf from a few rows over to one just sprayed, you immediately notice the entire surface has a shiny thin coating from front to back. And this is why the technology is so exciting for the vineyard manager: fantastic coverage but with no waste.


The concept is surprisingly simple. Think in terms of metal filings drawn to a magnet, lint to your clothes or dust on a record. In science, it is known as Coulomb’s Law, where opposite electrical charges attract and “like” charges repel. In everyday life, it is known as powder coating.

The automotive industry has been powder coating cars for years. Nowadays portable systems are used on everything from people standing in tanning booths to hospital rooms needing complete antiseptic coverage. The concept is to create opposite electric charges between the “paint” and the object.

With electrostatic vineyard sprayers, everything begins with the spray nozzle. A typical droplet of spray from a conventional air-blast sprayer is around 250 microns. Electrostatic uses an “air-assisted” nozzle, whereby the solution (chemical and water) is combined in a “shearing” action, which atomizes the particles down to 30 to 50 microns. Then, just before the mist exits the nozzle, it is exposed to a negative charge. As the mist enters the canopy, it stalls, resulting in a “charged” fog inside the canopy; and this is when the magic begins.

The electrically-charged particles are automatically attracted to the “grounded vine.” This charge is small, but the force attracting the spray to the “target vine” is up to 75 times the force of gravity. The particles actually reverse direction and coat the back sides of the vines throughout the entire canopy. This is referred to as “electrostatic wraparound.” In comparison, a 250 micron droplet simply runs off a leaf and onto the ground.

Then there is the second half of Coulomb’s Law, that “like” charges repel. Since all of the spray particles leaving the nozzles have the same charge, they cannot collect into large droplets, which again fall to the ground. At the same time, the swirling particles are not attracted to areas already coated and continue to seek out uncovered surface areas until there is uniform coverage (disposition) throughout the entire canopy. You have essentially “powder coated” your entire vine with no drips or runs. Since diseases and insects are usually hidden on the undersides of surface areas and deep inside the canopy, they can continue to survive if the spray coverage is spotty. The distinct advantage of electrostatic spraying is the increased chance of the disinfectant finding its target. One crop with serious disease issues is strawberries, which are dense, grow very low to the ground and are highly susceptible to mites. Electrostatic is now becoming the sprayer of choice because the pesticides migrate beneath the leaf.


Overall Efficiency
We now live in the age of sustainability, and “electrostatic thinking” is a perfect fit. Many environmental impacts are lessened with electrostatic, including chemical drift, the amount of chemicals and water applied, noise, soil compaction and fuel savings.

We also live in a time where vineyard managers increasingly face demands from local, state and federal agencies (EPA) mandating less chemical and water usage; these will only multiply. In June 2009, a group of 28 farm worker unions and advocacy organizations petitioned the EPA “to stop pesticide poisoning of farm worker communities and uphold the Obama Administration’s commitment to environmental justice,” according to a US Newswire article.

Water Savings
Each grower will experience different savings based on his comfort level of application; but moving from 250-micron droplets to a 50-micron mist immediately reduces water usage.
“The idea is not to drown the insect,” said Dr. S Edward Law, director of the Applied Electrostatics Laboratory, Biological and Agricultural Engineering Department at the University of Georgia. “Effective pest control is dependent upon uniform distribution, and reducing the micron sizes may give you as much as 10 times the coverage in the same amount of water.”

“The 100-gallon tank on my electrostatic sprayer covers eight acres in full canopy,” said Marty Hedlund, vineyard manager at Dehlinger Winery in Sebastopol, California. “Our 300-gallon conventional sprayer covers 2.5 acres.”

Brian Wallingford of Mesa Vineyard Management in Templeton, California agreed. “We noticed the reduction in water use almost immediately,” he said. “We went from applying over 100 gallons per acre down to only 30. With that type of decrease in water, along with chemicals, means the machine will pay for itself in two years.”

As an example: a 100-acre vineyard using roughly 100 gallons of solution with a conventional sprayer uses 10,000 gallons of water. Marty Hedlund, at 12.5 gallons per acre, would use only 1,250 gallons.
Less water with better targeting also means chemicals remain on the vine and not on the ground. Puddling on the leaf structure is also eliminated, reducing phytotoxicity and burning.

Chemical Savings

“Once we purchased our electrostatic rig, we were able to reduce applications down to three, two and now only once each year to treat for Pacific mites,” said Wallingford at Mesa Vineyard Management. The company currently oversees 5,000 acres in Monterey, San Luis Obispo and Santa Barbara counties. Combined, that is substantial savings.

But efficiency is also realized by some growers who say they use only one- third of the
recommended label law concentrations.

“Label laws are an example of the government deferring to the chemical companies,” said Dr. Ken Giles, professor of Biological and Agricultural Engineering, UC Davis. Many think label laws, as they are usually called, are a mandate from the government; but it is only a chemical company’s law and refers to its warranty.

In addition, the majority of dilution rates on the labels are based on the 250 micron droplet, not a 50 micron mist. “Conventional application is easy, and sloppy is forgiving,” continued Giles. “The recalculation of dilutions is up to the conscientious grower.”

This is further supported by Lea Brooks, assistant communications director for the California Department of Pesticide Regulation (CDPR). According to Brooks, “The EPA has the final say. But unless prohibited by label warning, the amount of pesticide applied can be reduced below the amount specified on the label. However, even though the lower use is not illegal, it may break any warranty by the company.” By the way, studies are available from the CDPR that suggest they are quite positive about electrostatic technology.

In either case, whether because of fewer applications or increased dilutions, the amount of chemicals used is drastically reduced. Finally, the efficiency of electrostatic not only saves water and chemicals but, resultantly, labor.

Labor Savings
“We have vineyards scattered all over the hills, and with 12 gallons per acre versus 100, our operators spend far less time driving back to refill and more time spraying,” said Mark Lingenfelder, executive vice president, vine- yard operations for Chalk Hill Estate and Winery in Healdsburg, California.

Matt Manna of Manna Ranches in Acampo, California concurred. “We manage thousands of acres and typically used multiple water trucks. We can now continue operations all night and refill only four times per shift as opposed to once per hour,” he said.

Obviously this affects labor costs, but there are additional side benefits due to less “commuting.” With less driving back and forth, less soil compaction occurs. Less drive time also means greater fuel savings and also less wear- and-tear on equipment.

There are also times when electrostatic spraying affords the grower unexpected benefits. The most obvious are issues with neighbors related to drift and noise.

Regardless of vineyard size, one of the most important concerns for the EPA and CDPR is unintended chemical drift. Make no mistake, this will continue to evolve as a major issue along with over-application of chemicals.

The University of Florida’s Institute of Food and Agricultural Sciences has spent a considerable amount of time studying drift, both “swath” and “long-range.” Swath is the lateral displacement of particulate in the immediate location while long-range implies problems when particles settle on other crops that are sensitive to that chemical.

Drift is dependent on wind speed, humidity, height of emission and, most of all, droplet size. A 400-micron droplet will fall to earth almost four times faster than a 200-micron one. Since electrostatic sprays are only 50 microns, care must be exercised. Obviously, one should not spray in windy conditions. In normal situations, however, the high levels of electrical attraction will easily control most potential problems.

“Chalk Hill Winery has vineyards that were isolated when planted but are now surrounded on three sides by housing developments,” said Lingenfelder. “In order to foster better relations with those close to our operations, we felt it imperative that we minimize spray drift. With electrostatic it is virtually eliminated.”

One of the sure signs of good electrostatic spray disposition is how quickly the spray cloud is attracted directly to the target zone. It does not remain in suspension over the canopy. “With our single row sprayer, you can literally watch as the cloud of particles separates and is attracted into the two sides of the row,” said Hedlund at Dehlinger Winery.

To see if the system is working prop- erly, an easy test is to watch the spray cloud while you alternate power to the electrostatics and look for changes in the pattern. With power off-then-on, the cloud will immediately be diverted in the direction of the canopy.

Again, timing is important, and spraying in windy conditions should be avoided regardless of sprayer. At the same time growers are concerned with drift, they must also be cognizant of neighbors and noise.

Noise Abatement
A traditional complaint with air-blast sprayers is the inherent noise produced by the fan blades, similar to the sound of an airplane propeller. New designs now incorporate enclosed rotary vane blowers instead of fans, resulting in substantial sound reduction.
One manufacturer is currently experimenting with automotive superchargers as the air source. So far the results are positive.

Lingenfelder at Chalk Hill had issues with sound as did Hedlund at Dehlinger, whose owner resides on the property and objected to excessive noise.


Choosing the Right Equipment
Each manufacturer we approached offers different sizes of spray rigs, from a simple three-point attachment and a maximum 100 gallons to tow-behind trailers holding up to 600 gallons. Total acreage will determine tractor size and spray rig design. Single-row and two- row systems are available.

Small Growers
For the large percentage of small vine- yards, the three-point is probably adequate. The most obvious reason is due to the substantial increase in effective spray coverage. Most three-point systems have only 100-gallon capacities but will usually afford the grower eight acres of coverage. Less liquid means less weight and automatically allows for smaller tractors. At the same time, the new sprayers require considerably less PTO horsepower. With smaller tractors, growers can negotiate tighter row spacing, hillsides and row ends that require a tight turning radius.

Medium to Large Growers
Larger growers with expanded acreage and row spacing will be able to use larger equipment including over-the- row booms. Manufacturers already have spray boom designs that accommodate most trellising configurations, and the equipment is surprisingly adjustable. The good news is these companies are also capable of custom fabrication for the individual vineyard.


A typical tow-behind air-blast sprayer will be around $15,000 to $18,000 while a comparable electrostatic can cost twice as much.

A typical three-point electrostatic (100-gallon) rig may be $20,000. But the payback with efficiency can easily offset additional expense.

Brian Wallingford at Mesa Vineyards Management said, “I needed to get my customers to budget additional funds to allow me to buy electrostatic. I explained I was saving $14,000 in chemicals (alone) on 300 acres, and the cost of the rig would be recouped in two years.”
He added, “When you also consider savings in water usage, we can plan for the future. Currently, my counties require meters on all wells, and we are required to report usage on an annual basis. We are not paying yet, but we have concerns about the next few years.”

A good exercise is to discuss savings with each manufacturer. They typically have charts that will compare tractor fuel costs per acre, labor, chemical and water savings. Then get a list of their customers and make some phone calls. We found talking to growers using electrostatic will answer a host of questions.

According to Dr. Giles at UC Davis, “The downside of this new technology is, if not operated properly, you can get mixed results. It can work extremely well with proper technology transfer.” He added, “The operator cannot treat them like the old sprayers. They require more management effort and more operator training.” It is highly recommended to query vendors about their training programs and support.


Two things are important with electrostatic sprayers: keeping the nozzles clean and monitoring the electronics.

With the small orifices it is imperative to thoroughly flush the units after each use and then to check the spray patterns of each nozzle. Originally there was a problem with powdered sulfurs due to poor mixing and suspension resulting in plugging. Manufacturers have addressed this with better agitation and pumps. Look for centrifugal pumps with improved silicon-carbine seals. Seal erosion due to suspended solids has essentially been eliminated.

At the same time, since the electronics are the heart of the system, a different type of maintenance is required compared to a conventional sprayer. For the electronics to work, all that is required is a 12-volt battery on the tractor, which is then amplified through step-up transformers to thou- sands of volts. While this sounds dangerous, there are no amps involved so safety is not an issue.

What is most important, however, is to check each nozzle for proper voltage. As mentioned, a quick “in-field” test is to simply observe the spray cloud during operation. Turn the electrical power off and then back on and watch the immediate change in disposition. The purchase of this equipment should include a volt meter for individual nozzle testing. While it is not difficult, it may involve additional time.

Beyond this, maintenance will be the same as any rig including winterizing the mechanicals, checking belts and gear box oil. Warranties are normally one year, and all companies claim to maintain a healthy supply of technical assistance and parts.


Of the three academics we interviewed for this article, the consensus was this technology is the future for chemical application. The growers using the equipment agreed, and even the CDPR likes electrostatic spraying. And as usual with any new technology, it took time to fine-tune the mechanicals, and that has been done.

The basic concept of efficiency is what is so exciting and will help growers to look forward—specifically using less water and fewer chemicals. It is also reasonable to assume government regulations are going to increase, so it makes sense to plan for tomorrow by being as efficient as possible today.

“Electrostatic sprayers are so efficient because they save time, reduce water consumption, reduce chemical volume and provide excellent coverage,” said James Beville, vineyard manager at J&L Farms in San Lucas, California. “Due to the low PTO demand, we are conserving fuel. We are spending less time in the vineyard, thereby reducing compaction and extending tractor life. I do not understand why anyone would want to spray any other way.” wbm

Bill Pregler has worked in the winery equipment industry for many years and is a staff writer for Wine Business Monthly.

New Electrostatic Sprayers for 2012

Designed for ATVs in small vineyards, lower weight units are smaller and use less fuel.

Article taken from Wine Business Monthly, by Bill Pregler.

It SEEMS EVERY YEAR I visit with the folks at On Target Spray, who manufacturer electrostatic spraying equipment. As their name implies, they really know how to focus on the specific needs of vineyards, and their latest entry looks to be spot on.

On Target had been approached by numerous small growers (5 to 8 acres) who had embraced the science of electrostatic spraying but were limited by the size of their vineyards or tractor horsepower or had narrow row spacing issues or were on a limited budget. Enter On Target’s new design, the Cube™.

As a totally self-contained unit, the Cube is only 36 x 36 x 24 inches and, even with a 50-gallon mixing tank, weighs in at only 540 pounds. It is designed specifically to nest in the back of a Gator-like vehicle or, with optional wheels, be towed behind an ATV. My research shows almost all ATVs qualify.

No need for tractor PTO as this rig is powered by a factory-approved, gas-stingy Honda V-twin engine. I was advised the low fuel consumption allows for three full hours of continuous operation. Like all sprayers from On Target, the Cube features the quiet, German-made Kaeser Tri-lobe (rotary) blower instead of a noisy vane-fan so typical in other spray equipment. A Hypro pump delivers the liquid and agitates the tank.

Many people might question the use of a small mixing tank, but water and chemical savings are two distinct advantages of the new generation of electrostatic sprayers. For an in-depth review of the technology, visit my September 2009 Product Review, “Powder Coating your Vines.”

Based on Coulomb’s Law, electrostatic works because opposite electrical charges attract. In this application, the atomized 30- to 50-micron spray droplets emerge with a positive charge and are immediately drawn into the canopy of the negatively-charged “grounded” vines.

Once inside the canopy, the swirling action of this “mist” actually results in chemicals reaching behind and adhering to the backs of leaves. Think in terms of metal filings and a magnet. It is similar to paint technology in today’s car factories; you are essentially powder-coating your vines.

Some growers claim water usage is reduced up to 75 percent, with added savings from using only 30 percent of the normal amount of chemicals. With such efficiency and less need for liquid comes the reduction of gross vehicle weight, which is what the Cube is all about. You can go further into the vineyard with a single load, using a smaller vehicle.

With the low-volume application, the Cube’s 50 gallons can cover up to an 8-acre vineyard. As an added plus, electrostatic spray adhesion and small droplet size result in a significant reduction in runoff and wasted product (money) on the ground.

Less weight also means the grower can now enter the vineyard earlier, during wet spring conditions, when a tractor cannot.

The spray booms are actually tubular manifolds that contain the spray nozzles. The Cube has four manifolds with ball-swivel clamps for maximum adjustment of left and right spray patterns during a single pass. Depending on the trellis configuration, manifolds can be added later or turned on and off, depending on need.

The 50-gallon tank will last for 72 minutes with all nozzles on. In the early season, the tank will last for 160 minutes with two spray manifolds turned off.

As is typical with On Target, the company will customize your spray pattern. As a sole proprietorship and OEM manufacturer, it is more than happy to work with the grower to deliver the best design for the specific application.

What’s Cool:

Between all the cost savings, from chemicals and smaller tractors that use less fuel, to less time and labor in the vineyards, the folks at On Target really help amortize your equipment purchases. I have seen charts comparing air blast designs to electrostatic technology, and the differences are impressive.

Using less water and substantially less chemicals are also good for our environment. The adhesion of electrically-charged particulate helps reduce drift and runoff.

At last, all of this cutting-edge technology is now available to the small grower with an ATV.

For more information, contact On Target Spray or Progressive grower Technology, inc. at (503) 329-8120 or ontargetspray.com. WBM

New Narrow Row Electrostatic Sprayer

Compact, affordable and targeted spray rigs for high density growers

Article taken from Wine Business Monthly, by Bill Pregler.

IN A SEPTEMBER 2009 PRODUCT REVIEW, I wrote in-depth about new generation electrostatic spray rigs. At the time virtually every academic I interviewed (from those in the agricultural engineering departments at the University of Georgia and UC Davis to Fresno State’s director of viticulture) said the future of chemical application was electrostatic. Even the people at the California Department of Pesticide Regulation (CDPR) liked the technology.

Years ago the units had problems, but all early R&D kinks have been ironed out, and today the equipment delivers incredibly precise chemical disposition. Naturally, it was only a matter of time before even these new designs began to evolve.

Enter a new rig, On-Target sprayers from Progressive Grower Technologies, Inc. in Wilsonville, Oregon. Already a major supplier to a wide spectrum of crops from orchards to strawberries, they continue to focus design energy on vineyards. No sooner did I walk onto the exhibit floor at this year’s Unified Wine & Grape Symposium than I saw their latest entry. They currently make sprayers for larger vineyards, but the new units are specific to narrow row (4 to 6 foot), high-density plantings.

At a narrow 32-inches wide, this sprayer’s target market is definitely the small grower who trellises his grapes on hillsides with tight turning radiuses. It is com- pact, lightweight and carries only 70 gallons. That does not sound like enough, but with the precise spray coverage of electrostatic technology, it is plenty. Less weight also means smaller tractors. The unit I saw was compatible with a 25 Hp— PTO John Deere Model 790 tractor.

This new unit comes with either single row application (spraying left and right) or overhead booms to cover two rows at a time.

Electrostatic spraying is for those concerned about saving water, spending less on chemicals and labor, noise problems with neighbors and getting the best application possible. The concept is similar to powder-coating a car.

Automakers have been using electrostatically charged paint for some time. In the wine world, the concept is now the same. The grower gives the chemical-water spray (“paint”) an electrical charge and directs it to the “grounded” vine.

It works because of Coulomb’s Law, which states opposite charges attract and like charges repel. The key is to atomize the mixture to 30- to 50-micron droplets versus 250 microns for a typical air-blast sprayer. Chemical, water and air are combined in a shearing action from air-assist nozzles. This atomized solution emerges as a “mist” of chemical in a low pres- sure, low volume concentration.

Once inside the canopy, the spray will swirl and actually reverse direction, attaching to the backsides of the leaves.  Also, since the droplets are all the same charge, they repel. They will not collect into large droplets, which typically run off onto the ground. The spray continues to circle until the entire surface is covered. The charged mist is drawn to the leaf, similar to dust on your records or metal filings to a magnet. You have essentially powder-coated your vineyard.

Hence the savings: considerably less water and chemicals without costly overspray and runoff. According to some growers, the efficiency of electrostatic technology reduces water usage by 75 percent while using only 30 percent of chemicals. This means you go further into the vineyard with one load and keep your driver spraying and not driving for refills.

The On-Target sprayer uses a quiet Kaeser blower instead of vein fans. The sound of the tractor is actually louder than the sprayer. The German-made blowers are highly reliable and use stain- less rotary lobes. Maintenance is almost none, and I was told using synthetic oils can extend operating time to 5,000 hours.

The small-aperture nozzles of electrostatic sprayers must be thoroughly flushed after use. Also, since electronics are at the heart of the system, each nozzle should be checked for proper voltage. A volt meter is included, but a simple in-field test is to turn on the spray and then alternate the on-off electrical switch. The operator will immediately see the change in the spray disposition. I personally watched as the “cloud” was immediately pulled into the canopy.

Progressive Grower Technologies, Inc. is an O.E.M. manufacturer and therefore can custom-fabricate for specific applications. They make much larger rigs (up to 600 gallons), but these new condensed units help spread the science to the smaller grower.

What’s Cool: It is terrific when a great technology continues to evolve and starts reaching out from orchards to row crops and vineyards. Even better, electrostatic spray rigs are now getting more compact and affordable for those growers with small, difficult-access vineyards.

I like the concept because it is efficient and judicious in water and chemical usage. And because the chemical application is so precise and targeted, growers report better overall results, which translate into even less spraying. It is fascinating to attend a demonstration and watch the mist separate and move into a canopy: No blast, no overspray and no noise.

Electrostatic Sprayer to Benefit Smaller Growers

The latest machine by On Target Spray Systems combines the latest technology with a price that won’t send small growers running.

Article taken from Grapegrower & Winemaker Magazine, December 2012 – Issue 587 – by Kellie Arbuckle

A SPRAYER THAT provides the benefits of electrostatic technology at a competitive price has been specifically developed for smaller grapegrowers. The Cube is the latest spray machine by On Target Spray Systems – the developers of crop spraying technology that uses an electrical charge to create a fine mist of uniform, electrostatic droplets.

Until now, this technology has only been available on the On Target Sprayer – larger spray units ranging in price from $28,000-55,000. The sprayer boasts thorough coverage, up to 90% less water usage and a reduced need to repeat application, resulting in savings on money, diesel, labour and chemicals. Other benefits are that the machine can be used with almost any chemical and it’s less noisy.

But while the benefits are vast, the price of the technology is often enough to put growers off altogether. Willie Hartman of On Target Spray Systems said The Cube was designed to specifically cater for these growers.

“We had a lot of vineyard managers who liked the technology – that it’s environmental and works well – but they had a hard time justifying the costs,” Hartman said.
The Cube costs around $24,500 in Australasia. It is a self-contained unit and is powered by a low-fuel consumption Honda V-twin engine. Hartman said the second issue for many small grapegrowers was the need to buy a tractor that had enough horsepower to run a conventional airblast sprayer.

“That’s why we decided to create a self-contained unit – so they can use the machine with a tractor that doesn’t require high horsepower.”

The Cube takes up to 190 litres of chemical, which can cover up to an entire three-hectare vineyard with a low volume application.

Weighing just over 240kg, The Cube is a relatively light- weight machine and less likely to compact the soil.

The machine is also suitable for attaching to an ATV, for fitting through narrow rows and features a quiet German-made Kaeser Tri-lobe rotary blower.

“The payback on this system is also incredibly quick. Large growers can pay the machine off in just a season, while for small growers it might take about three years,” Hartman said.

Aaron Weinkauf, winemaker and vineyard manager at Spottswoode Estate in St Helena, California, bought The Cube for a number of reasons.

“Compaction can be an issue and spraying is the most common practice we do in the vineyard, so the reduced weight was highly attractive,” Weinkauf said.

Spottswoode has been farming organically since 1985, so reduced chemical input was also a bonus of The Cube.

“Prior to The Cube, we were using an airblast sprayer and finding that the coverage was always good on one side, but negligible on a shielded side,” Weinkauf said.

“Working with the ‘charged technology’ seemed very realistic. We specifically chose to work with On Target because we appreciated the sensible design features, the more commonly available parts and what we believed to be a sincere desire to make changes and improvements to the unit.

“We were able to spray more quickly using less water and product, and we had no considerable mildew issues.”

While Weinkauf spent the same amount on The Cube as he did on his previous airblast sprayer, he says the savings of The Cube have held true.

“We were using close to 15 per cent of the water we would have used with the previous sprayers and 30-40 per cent of the chemical product that we would have been using,” he said.
“Plus, On Target has been great to work with and we do plan to purchase another.”

More information at www.ontargetspray.com or to arrange a demonstration, phone sole Australasian agent Greg Marshall on: (08) 8388 4414 or 0407 014 627.

Electrostatic Sprayer Hits the Spot

A vineyard sprayer that works on the premise of ‘opposites attract’ has been given the thumbs up by one of Australia’s most respected winemakers.

Article taken from Grapegrower & Winemaker Magazine, October 2012 – Issue 585

COMMONLY USED FOR table grapes in Chile and the US, the On-Target sprayer is now gaining traction in the Australian winegrape industry.

It features a spray nozzle that uses an electrical charge to create a fine mist of positively charged droplets which are attracted to the negatively charged surfaces of the plant, resulting in thorough coverage.

Brian Croser, winemaker at Tapanappa Wines, has been comparing the machine against his air blaster for the past eight years, after a prototype was made specifically for his 1.5m vineyard rows.

He says the advantage of the on-target sprayer is that it provides coverage in hard-to-reach places at small volumes.

“What attracted me to this is that it’s so targeted and doesn’t require high volumes of spray material,” said Croser, who bought the machine in 2004.

“We tested it against the air blaster using fluorescent dye and found it gave a much more thorough coverage, whereas with the air blaster, I struggled to get the spray on the backside of the bunches and the underside of the leaves.”

Potential for huge water savings

Australasian distributor Greg Marshall, who designed the prototype for Croser, says the On-Target sprayer is capable of savings of up to 90 per cent on water usage. “A conventional sprayer wastes more than 40 per cent of chemicals due to runoff and drift. Drops are large and they drip off the plant,” Marshall said.

“With on-target sprayers, charged particles wrap around crops like magnets, providing full coverage and reducing drift. The small droplet size and electrical attraction nearly eliminates runoff.”

As a result of increased coverage, repeat applications are reduced, leading to savings in money, diesel, labour and chemicals, making them an idea choice for growers looking for a sustainable option. They are also less noisy due to a rotary lobe blower, making them socially

Marshall, who has been providing demonstrations of the machine in Australia over the past season, says interest is growing and he is planning to hold more demos this month throughout Victoria and South Australia.

So how exactly does it work?

“Chemical is fed through a jet and as it leaves the jet, it is sprayed out through the nozzle where it picks up the air. As it leaves the air, it picks up an electrical charge which is positively charged.

“Because positive particles repel each other, when it hits the plant, it provides an even coating because the droplets don’t hit each other. They don’t form larger droplets that fall to the ground – they hit the plant, which is naturally earthed.”

The On-Target sprayer ranges in price according to type and size. For a single row, the machine would require about five spray nozzles per head (of which there are four), and would cost about $28,000. For sloping blocks where you can fit the machine to the back of a tractor or for the smaller vineyard (about 10ha), the cost is about $40,000 – the most popular.

Croser says the machine would be best suited to vineyards with narrow rows. The only limitation, he says, is the need to ensure nozzles are clean and still working properly because they are so fine.

“It’s not high maintenance, it’s just a task that needs to be attended to. We clean the nozzles thoroughly after every spray,” Croser said.