A small, remote-controlled helicopter successfully applied a test spray to the University of California Oakville Experimental Vineyard, June 6, as part of a public demonstration.
The concept is nothing new, having been used for 20 years in Japan to treat rice fields.
The motorcycle-sized chopper is being tested in the United States to see if it's safer and more efficient than tractors to apply pesticides, according to a news release.
UC Davis is one of the few universities in the nation with a Federal Aviation Administration permit to test unmanned aircraft.
The testing at Oakville began in November 2012.
The site was chosen because it's a working vineyard and meets FAA requirements for flight zones for remote-controlled aircraft.
Experienced Yamaha flight instructors from Japan trained UC Davis researchers Ken Giles and Ryan Billing to fly the remote-controlled chopper, which is similar to smaller ones hobbyists fly.
In Japan, about 2,500 of the RMAX helicopters are used to spray about 40 percent of the rice fields.
Currently, the researchers are only applying water and are using water-sensitive paper to gauge application accuracy.
The craft can carry up to 16 liters, or slightly more than 4 gallons, of liquid.
The recommended spraying speed is about 15 mph.
Eventually, the researchers will use commonly used pesticides in the tests.
They also will compare how the pint-sized chopper does compared to tractor-drawn spray rigs.
Results of the study, expected later this summer, will help guide where and how the mini-choppers may be used in U.S. agriculture.
See the helicopter in action at YouTube.