The Way To Spray
January 21, 2011 
Spray technology is always evolving. Today’s sprayers are infinitely more efficient than older technology, which is great news for growers and their bottom lines. Andrew Landers, pesticide application technology specialist at Cornell University, says he considers the biggest advancement in spray technology for tree fruit and vines in the last 50 years to be the ability to adjust air flow on the move.
“There is huge interest in this subject,” Landers says. “Technology that has been available for about three years is the adjustable flap tower sprayer. We see tall tower sprayers that have a flap on the edge that adjusts air flow. These flaps are manually adjusted to limit the amount of air coming out, so the air flow matches the canopy requirements.”
He notes that the fundamental shift in the way tree fruit is grown has dictated changes in spray equipment. In the past, trees were as tall as 30 feet and required huge sprayers to blow droplets into the tree. Now that many fruit trees are shorter and narrower, that high volume of air is unnecessary.
“Research conducted at Cornell has been on controlling air flow,” says Landers. “The louver or flap can be fitted to a conventional air blast sprayer. We have developed a louver that we have a patent for and will sell to use with a conventional or regular air blast sprayer.”
Another noteworthy machine, Landers says, is the multihead fan sprayer that can also adjust air flow by changing the fans driven by hydraulics, to match the canopy. “In spindle trees in New York, we have done three years of trials,” he says. “We had growers spraying only from one side of the tree. The result is that growers have halved their tractor and fuel use or doubled the area they can spray comfortably.”
Proper Coverage
Manufacturers of spray equipment are working hard to update their technology on a regular basis, too. Nelson Hardie, for example, is introducing a new sprayer in 2011 called The Beast. This sprayer features twin 46-inch diameter, 10-blade aluminum fans and a 325 horsepower diesel engine. According to Nelson Hardie’s Jim Bennett, The Beast is designed to spray tall trees, such as some walnuts and pecans, with ease. It will be available with a 1,000-gallon tank. “Growers tell me they want great coverage in and through the leaves and limbs, accurate application amounts so they don’t waste chemicals by applying too much, and a machine that is dependable and is ready to spray when they need it, without a lot of maintenance,” Bennet says.
One of the best ways to ensure proper coverage, he says, is to match the sprayer to the orchard and air delivery design. “The chemical is suspended in the water droplets, and those droplets are carried into the tree with the air from the sprayer fan,” he says. “If the sprayer is too small and the air does not reach the top of the trees, then spray coverage is limited.”
Maximizing Efficiency
To achieve full coverage and maximum efficiency, Bennett says calibration is key. Another helpful tool is Nelson’s One Shot tree recognition system, which keeps spray valves turned off until the One Shot Sensor detects a tree. It turns off again after the sprayer passes the tree. “This is particularly helpful with young orchards where there are long spaces between the trees,” he says. “The sprayer will not spray the spaces, so it is good for the environment, and the grower enjoys a savings by using fewer chemicals. Plus, you don’t fill up the sprayer as often, so there is additional savings in time and labor.”
Reducing Drift
Drift is an issue all growers battle, and thankfully new technology can help reduce it. A new over-the-row sprayer model from Progressive Ag Inc., for example, offers a six-spray head design to improve coverage and reduce spray drift.
Regardless of the equipment they’re using, however, Mark Ryckman of Progressive Ag says growers themselves can play a huge part in the amount of drift and waste they’re creating. “Growers and operators should always be aware of road traffic and make sure their spray patterns are hitting the target area,” he says. “Always keep in mind the prevailing winds and also machine calibration to prevent runoff and wasted material.”
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