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.”