Posted: Tuesday, October 09, 2012 9:35 AM
Dan Wheat/Capital Press
Mark Brown II, a crop duster from Quincy, Wash. and president of the Association of Washington Aerial Applicators, sprays pink water to fine tune droplet size and spray pattern. The association helped pilots calibrate equipment at Moses Lake Municipal Airport, Oct. 8, to meet industry food safety standards.
By DAN WHEAT
MOSES LAKE, Wash. -- It was clear, sunny and no wind -- a perfect day for crop dusters to fine tune the precision of their spray equipment.
A half dozen of them from throughout Eastern Washington gathered at Moses Lake Air Service at Moses Lake Municipal Airport. They took turns flying multiple passes just a few feet above a string on the ground and spraying pink-colored water.
Strings were analyzed by computers and three certified analysts for droplet size and consistency of spray pattern.
"We want it to come out evenly," said Mark Brown II, a pilot for Quincy Flying Service and president of the Association of Washington Aerial Applicators.
Differences in planes, like having a certain air scoop or not or stainless steel spray boom hangers cause differences in spray, he explained. Applicators switch nozzles, depending on what they are doing.
Weed and fungus control of row crops and some wheat and dry fertilization of wheat, potatoes and beans makes up most crop dusting in the Columbia Basin, Brown said.
Smaller droplet sizes are preferred for performance of fungicides and larger droplets are needed for drift control with herbicides to control weeds, Brown said.
But if droplets are too large then "you don't get the coverage," he said.
Droplets of 250 to 300 microns is good for fungicide and pilots try to keep 90 percent of their spray on their target of, say, 275 microns, he said.
Planes that meet association standards are certified as SAFE. That stands for Self-Regulating Application and Flight Efficiency and was developed by the National Agricultural Aviation Association in response to public concern over possible effects of spray drift.
The intent of SAFE is to show that ag aviation recognizes its responsibility to minimize the potential for adverse health and environmental effects of ag chemical applications.
"We are trying to mitigate drift and this fits in with GAP (Good Agricultural Practices) programs of growers, packers, processors, retailers, exporters and importers," Brown said. "They want to know our equipment is calibrated properly and this is how we test that."
Professional application analysis clinics, such as the one held Oct. 8 at Moses Lake, are a key part of Operation SAFE. The three analysts at the clinic came from Washington State University, the University of Idaho and the association.
Carol Black, from WSU, said all went well. "We want the best coverage with herbicide droplets, large enough that there's no off-target drift," she said.
Gavin Morse, 29, of B&R Aerial Crop Care in Connell, said larger processors are beginning to require applicators be SAFE certified and that those who aren't may find themselves out of jobs. He is secretary of the state association and said next year the clinic may be offered at a couple of locations on different days for more availability to pilots.