Editor's note: The following article was written by Steve Adler, associate editor of Ag Alerrt, a weekly newsletter from the California Farm Bureau Federation.
When farmers approach University of California, Davis, agricultural engineering professor Ken Giles to inquire about an experimental, remote-controlled helicopter being studied as a potential applicator for agricultural chemicals, they only ask two things: How well does it work and how much does it cost?
The short answer is that the results look promising so far.
Giles is the lead university researcher who is partnering with Yamaha Motor Corp. USA, to see how well Yamaha's motorcycle-sized RMAX unmanned helicopter can been used for agricultural purposes in the United States, including aerial applications of agricultural chemicals.
UC Davis has a permit from the Federal Aviation Administration to apply treatments with remote-controlled aircraft at the UC Oakville Experimental Vineyard. Field tests using only water applications began last November, and Giles and his team demonstrated the helicopter for reporters last week.
Their tests are among several involving use of unmanned aircraft for agricultural purposes, in California and elsewhere.
Data collected in the Oakville tests so far indicate the helicopter is providing thorough coverage across the vineyard and that the air currents stirred up by the helicopter rotors cause the spray to reach even the undersides of the grapevine leaf canopy, Giles said.
The RMAX is equipped with one 8-liter tank on either side of the fuselage, giving it the capacity to carry slightly more than 4 gallons of liquid before having to be refilled.
"We are able to cover the vineyard rows at about 12 to 15 miles per hour," said Steve Markofski, a Yamaha business planner and RMAX operator. "Even when factoring in the refill time and so on, the RMAX is very efficient. Given the current spray method, at full spray it can operate for about 10 to 15 minutes. It can cover about four to 12 acres per hour."
Giles added: "It is obviously faster than a tractor."
The FAA regulates use of all remote-controlled aircraft, he said. The aircraft operators—a two-person team of controller and spotter—must be trained and certified by Yamaha and then pass the written private pilot's knowledge test administered by the FAA.
Eventually, the research team plans to conduct application tests with commonly used agricultural chemicals. They will explore how well the helicopter compares to a tractor-drawn spray rig in terms of operator safety, cost and efficiency. They also are expanding the test flights to some Central Valley almond orchards.
"From the viewpoint of agriculture, we are looking at this as a way to improve the productivity and ultimately reduce the need for a lot of crop inputs. This type of vehicle allows you to do treatment and inspection of agricultural fields on a very focused basis," Giles said.
For example, he said, if there is a small area within a vineyard that needs a treatment for pests or something similar, unmanned aircraft can do it very efficiently.
"Hillside slopes are actually hazardous for operators of ground rigs, so when you look at spray operations, the unmanned aircraft brings us a new vehicle with which to do that," he said.
Specific protocol for operation of unmanned aircraft could be adopted by the FAA as early as September 2015. At that point, Giles speculated that some large growers may decide they want their own vehicle, while at the same time there may be pest control applicators that go into the business, buy the equipment and then provide the service to growers.
"It is reasonable to think that there might be existing aerial application businesses that expand into these pieces of equipment. It is part of their market and could be a reasonable step that integrates in with an existing aerial applicator business," he said.
A Davis-based startup company—Airphrame—created by three Stanford University master's program graduates, said it is making inroads in the remote-controlled aircraft business by developing low-cost, unmanned planes for commercial markets, with a heavy emphasis on agricultural applications.
"Most of the public perception of drones is that they are used as war machines. We decided to come up with another application," said Bret Kugelmass, an Airphrame founder. "We kept exploring different applications and agriculture kept coming up as a huge opportunity."
The company does not sell the aircraft. Instead, it offers its services to agricultural customers who want to check on a variety of aspects of their farms, including crop development, pest and disease problems, and irrigation monitoring.
"We have developed small electric-powered drones. They are about 48 inches wide and weigh only a few pounds. They can stay in the air for a long time and they can cover a large surface area. In a single flight, one of our drones can cover about 300 acres, which means we can collect a great deal of high-resolution digital imagery in a single flight," Kugelmass said.
Agricultural research on uses of unmanned aircraft is becoming more prevalent throughout the United States. At Michigan State University, for example, professor Norbert Mueller is researching how they can be used for various agricultural activities, including surveying fields; crop health and watering; bringing out pesticides and fertilizers or other beneficial substances; and herding or searching for animals.
Recently, remote-controlled aircraft have been receiving public scrutiny because of their growing use for military, intelligence and law-enforcement purposes.
"I share those reservations and agree that we need to be very careful about how we use unmanned aircraft," Giles said. "But with the color, size and noise of a motorcycle, this helicopter that we're testing is anything but stealthy and would be a great disappointment to anyone hoping to use it for espionage or other covert purposes."