Targeting application technology helps cut pesticide waste and drift in orchards
By Renee Stern
Nut and tree-fruit growers can simultaneously reduce pesticide application waste and lessen environmental impacts with tree-targeting technology.
Sensors and computer controls that open and close sprayer nozzles direct pesticides at their intended target: the tree canopy. The technology is available on new machines, or growers can retrofit older sprayers.
Durand-Wayland Inc.'s SmartSpray sees its targets with the help of waterproof ultrasonic sensors, emitting sound waves and measuring reflected signals to build a picture of tree rows as the tractor drives between them, says Rick Cordero, sales director at the LaGrange, Ga., company. Researchers also are exploring laser and infrared sensors.
"The more you spray and the more expensive your spray materials are, the quicker you earn (the equipment investment) back," says Franz Niederholzer, University of California Cooperative Extension farm advisor for Yuba and Sutter counties.
Cutting the amount of material sprayed doesn't change overall results, Niederholzer says. Sprayers deposit the required amount where it's most effective, reducing waste.
Savings versus costs
Chemical savings vary, depending on how uniform the targeted blocks are.
Storm damage had left holes in his apple orchard when Mike Wittenbach, co-owner of Wittenbach Orchard of Belding, Mich., first tried targeted sprayers. He used 25 percent less pesticide that year, but as replacement trees have grown, those savings now average 10 percent.
Wittenbach runs two targeted sprayers on 225 acres of apples. "I spend $100,000 a year on foliar applications," he says. "Ten percent is a two-year payoff."
Durand-Wayland's basic six-sensor SmartSpray system--three sensors per side--costs $14,000 to $16,000, Cordero says. A 10-sensor model is available for tower or oscillator sprayers.
Young orchards offer even greater savings potential, says Steven Mendonca, chief financial officer at Mendonca Orchards Inc. of Chico, Calif. Small trees that haven't filled out their 15-foot spacing require much less spray coverage, saving as much as 90 percent.
Tightly planted orchards with no missing trees, on the other hand, may produce only a 5 percent reduction. Mendonca's operation, with 500 acres of almonds and 40 acres of walnuts, averages 25 percent savings with two sprayers.
More than cutting pesticide costs
Reduced pesticide costs are the main draw, but both Mendonca and Wittenbach say they also gain time and labor efficiency from making each spray load go further.