Mobile testing program helps growers reduce drift by providing an orchard sprayer report card
By Vicky Boyd
Always on a quest to improve sprayer efficiency and reduce drift and environmental impact, Modesto, Calif.-area almond and walnut grower Paul Wenger switched to longer-wearing ceramic spray nozzles about 10 years ago.
He routinely measures nozzle orifice diameters to check for wear, and he keeps track of the amount of pesticides applied compared to the acreage.
“We know how long it takes to put out a tank—about 55 minutes,” he says. “If it’s taking less than that, we know something’s wrong, like a broken hose. We’ve got it dialed in pretty well.”
When Parry Klassen, executive director of the Dinuba, Calif.-based Coalition for Urban/Rural Environmental Stewardship, approached Wenger about being a test subject for the group’s new portable sprayer calibration instrument, he readily agreed.
The Austrian-built Pessl Instruments Sprayertest 1000, which measures individual sprayer nozzle output and overall spray distribution pattern, gave Wenger’s Nelson Hardie 500-gallon airblast sprayer passing marks.
“[The sprayer is] doing what it was set up to do, and if they’re getting the right output per acre, they’re doing fine,” says Robert McMurry, a CURES environmental technician from Davis, Calif.
But not all growers are as mindful of sprayer calibration as Wenger.
“We’ve found some growers who are on top of it, and [the calibration] is almost perfect,” McMurry says. “And other growers have sprayers that are really dirty, and you have to clean up just about every nozzle and you have to replace a lot of nozzles.”
The sprayer calibrations are part of a larger effort by CURES to educate growers about reducing pesticide runoff into California Central Valley waterways. The nonprofit group received a grant from California’s State Water Quality Control Board to purchase the $75,000 portable sprayer tester and conduct grower outreach programs.
The three-year project calls for CURES to test at least 100 sprayers. In its first year, the group has evaluated about 30, and the results are all over the board, Klassen says.
“We’ll use this as an educational tool, but it will also give us an idea of what’s going on in the sprayer fleet, Mobile testing program helps growers reduce drift by providing an orchard sprayer report card so to speak,” he says. “If it shows they are really a mess, then there will be more educational emphasis on tuning up sprayers.”