Testing Unmanned Helicopters for Pesticide Spraying in California

To some, the sight of a small helicopter hovering a few feet over a Napa Valley vineyard may be just a curiosity. To others its the future of California farming. One of those is Ken Giles, professor of agricultural engineering at UC Davis.

In Giles’ mind, agriculture has as much to do with unmanned vehicles as it does with tractors and threshers.

At the university’s research vineyard Wednesday in Oakville, Giles showed off one of those vehicles – a 200-pound RMax helicopter built by Yamaha. In flight the helicopter revealed surgical and lighting-fast movements over the vineyard.

In conducting such flights, Giles and his team are gathering data and weighing the feasibility of the unmanned helicopters for pesticide use. Wednesday’s flight was done with water instead of the pesticides.

The Federal Aviation Administration does not allow pesticide spraying from unmanned helicopters as it considers them “experimental” vehicles.

Giles expects the FAA will make a ruling as early as 2015 on the future of unmanned helicopter use. “In the U.S. right now there is no commercial use of this technology – it’s strictly a research and development effort,” he said.

UC Davis is one of five universities in the United States researching the use of the helicopters for agricultural purposes. It’s the only one looking into using them for pesticide use.

The entry point for the helicopters will be to use them on hillside farms, Giles said.

“The unmanned helicopter technology allows precision positioning,” the professor said. “Plus, the hillsides are hazardous and time-consuming to drive and spray for a tractor.”

On Wednesday, the helicopter offered a dance of precision as it hovered, then sped past row over row of vines to a top speed of 12 mph. It simulated the spraying of pesticide from two of its 2-gallon tanks. The whir of the rotor blades lightly disturbed the vines as if they were being whipped up by a storm.

Giles said that a tractor working the vineyard would have moved at a 3 mph clip, with maneuverability limited between rows.

The helicopter’s operation demands a crew of two – a pilot who controls the helicopter with the same type of joystick console used by hobby aircraft fliers – and a spotter who directs precise movements.

A recent study by the Association for Unmanned Vehicle Systems International contends the agriculture industry would be the largest market for unmanned helicopter technology. Giles said he has been working with almond farmers in the Lost Hills area of Kern County, who are eager to use the technology for pesticide spraying.

While new to California, the use of unmanned helicopters on farms is not new.

Unmanned helicopters have been in use in Japan for the last 20 years, said Yamaha helicopter pilot Steve Markofski.

There are 2,500 RMax helicopters in use over 2.5 million acres of Japanese rice farms, according to Yamaha. The government introduced them into the Japanese agricultural industry to address an aging farming population.

Unmanned helicopters also are on their way to being approved for use in Australia, mainly for weed control. In the agricultural community of Flowerdale, about 70 miles north of Melbourne, Australia, the RMax helicopters have been tested on Terry Hubbard’s blackberry farm. Typically, Hubbard uses manned helicopter sprayers to apply pesticides.

“Of the total of 2,100 acres, blackberry infestation would barely cover 100 acres, but they’re scattered clumps, and hard to access because of the hilly nature of the farm, hence the need for aerial control,” Hubbard said via email.

Hubbard said the unmanned helicopter technology is still too expensive to use exclusively. Harvesting about 4 gallons of blackberries would cost him roughly $800 in pesticide-spraying costs, he said.

“This is significantly dearer than a conventional helicopter,” said Hubbard.

He contends that one of the brightest benefits of using unmanned helicopters is environmental. “It must be remembered that the ability to target clumps of blackberry with minimal overspray means that chemicals go further, and non-target species are avoided.”

Hubbard said that there is ample evidence near his farm of widespread tree damage where chemicals are applied by boom sprayers from conventional helicopters.

For Giles, a hybrid of manned and unmanned aircraft would be the best use to safeguard the environment. “A big aircraft could spray the middle of a field and then an unmanned one can fly low and spray the boundaries.”

Giles said the rapidity of the unmanned vehicles would give farmers time to see if pesticide application is even needed. The time-consuming nature of manned vehicle spraying requires farmers to decide early on whether to spray a field to save a crop, he said.


10 comments

  1. sir,
    this flying choper is ver exciting to me in my farms in india.if u have any details please email me.thanking youy in advance.
    shri

  2. Unfortunately this particular use of UAV technology will not be going far any time soon in the US due to a couple of issues and when it does it will be limited to about 50 to 100 ships.
    1. Chemical labeling – US EPA puts minimum total application volume on labels for both ground and air. Most by air are a minimum 2, 3, 5, or 10 gallon rate per acre. In addition some chemical companies require even more for a guarantee of product in certain crops. Which is what makes the test in almonds laughable. I have friends applying fungicide TODAY in California to almonds at 20 gallons per acre. Doesn’t take long to do the math for the loads required when a grower turns in 5,000 acres to be done in the next five days for any of those rates per acre when using a 4 gallon capacity machine. In addition, many labels also now dictate the size of droplet allowed to be produced for the application of certain products. I don’t know how this boom/nozzle setup would meet those criteria given the volumes sprayed. Certainly one could approach the EPA to rewrite the labels, and it may happen, but as the UAV world is finding with the speed of the FAA to just to where these are legal to fly, let alone apply with, getting a large federal agency to change policy and rules will take years at best.
    #2. Financial feasibility – We are talking about a $100,000 piece of equipment, more than some real ag planes and helicopters, that initially at least according to Yamaha will need to be leased from them with trained operators, that won’t have the capacity of doing 10 acres per hour of production. That is going to put the cost per unit (acre) through the roof on application. Most current aerial applicators are between $7.00 and $20.00 per acre depending on total volume applied so to be competitive the UAV/crew/support equipment will be making around $70.00 an hour. It doesn’t pencil for either the service provider or the grower.
    #3. Production – *See 1 and 2.* In US agriculture things are getting bigger, not smaller, to feed the now 7.15 BILLION people on the planet. Thirty years ago a 400 gallon capacity airplane and 50 gallon capacity helicopter were the norm. Now 800 gallon airplanes and 400 gallon helicopters are the norm and a 1000 gallon airplane is now built and in production. We aren’t spraying 1 acre fields in the US. When a grower turns in a job to me it’s usually 250 to 2,000 acres (and I am in what is considered a small area now), it is only turned in once it is necessary due to the cost to the grower for chemical and application which means that they are already coming out of their skin to have it done yesterday which means that you’d better have a couple of pieces of equipment that can do 150+ acres an hour to get the job done NOW. As well, some types of application are time sensitive, as in 24 to 48 hours from the time it’s turned in or you will lose it all together. Compound demands like that with our never ending foe weather and you’ve got another reason to have to be able to MOVE FAST. Remember as well that production is not only capacity but working speed and swath width. Most airplanes today are going 130-160 mph and putting out swaths of 55-90 feet. The Yamaha’s 12 mph and 20 feet wide doesn’t even compare. If you only get from sunrise until 10:00 before the wind comes up you’ve GOT to be able to cover the acres. Also in all of the videos I have yet to see one hot load and keep going as we do in the real world of production. We may start up at sunrise, not get out but to pee, and not shut the engine off until sunset 12+ hours later. Agriculture is not a 9 to 5 Monday through Friday thing. You go when the work is in front of you and you work until it’s done, usually for between 45 to 100 days depending on the season. So the amount of acres you can do per hour equates to per day, to per week, to per month, to per season and THAT is what a piece of equipments gross potential is to be able to pay, or not pay, the bills.
    #4. Dry work capabilities. – Although Yamaha does offer dry spreading equipment as an option the concept of utilizing this piece of equipment is even more laughable to the point of being comedic. Case in point; a common application of nitrogen for us would be 100#’s per acre of urea fertilizer on many crops. Again, when my growers call (and I have worked in 14 states on over 20 different crops for reference) they turn in say 1,000 acres. So now you have 100,000#’s of product to move, NOW. Fertilizer is usually applied based on tests of plant tissue samples taken the previous week. So when a sample comes back low and it has been a week since it was taken, guess when the grower wants the fertilizer out? That’s right, yesterday. For me our 500 gallon airplane carries about 3,000 pounds of urea, or a 30 acre load. Which means that it takes me about 34 loads total or 17 loads per airplane, at about 3 loads an hour that’s just over 5 hours to complete the job with BOTH planes, or 10 hours with one. Again, landing-loading-taking off-putting the load out-doing it again, WITHOUT STOPPING. The number of loads required to do the same job with an RMax and the time is staggering to think about. Dry is one of those cases where you have to do it if you want the liquid, customer service.
    #5. Worker Protection – For the last 20+ years our industry has been working to remove points of possible human chemical exposure through technology. Differentially corrected GPS in the cockpit for guidance has removed human flaggers from the edge of the field. This evidently puts TWO back in there with no cab for protection!
    Closed loop mixing systems with higher capacity aircraft has not only reduced exposure points but less loads reduces the number of times an incident can happen. These tiny ships incrementally compound the potential for mixing/loading incidents on a per acre applied basis.
    #6. Precision of application. – in the video footage I have seen of these UAV helicopters it appears that most of the flying is done visually by the operator. 99% of our industry’s aircraft now have differentially corrected GPS for guidance through the field to ensure no skips and only proper overlap. These units would possibly need to be adapted to make the RMax truly accurate. In addition to the GPS we also have flow control systems to ensure accurate application rates across the whole field no matter the wind direction or hilly terrain. It looked to me as though the operators I saw varied speed occasionally thus putting more product on the slower portions of a pass and less product on the faster passes.
    #7. Other thoughts. – Certainly there will be a use for these in very specific area’s. Most of what I see in the various video’s is very confined area operations in close proximity to houses, etc. Their usefulness in the US even for this type of application will come back to EPA chemical labels as many aerial labels have setbacks of 25-150 feet from homes, waterways, etc. So if a field is only 50 feet wide right next to a house you could possibly only apply half of the field. Due to this it may also come down to the fact that a Kubota with a pull behind sprayer driven by a Mexican for $12.00 an hour will be not only moe cost effective but the only thing possible due to fewer restrictions on ground labels even for those little patches.
    As far as image data gathering is concerned, yes, I agree that they will be useful for that. Probably not the RMax though as there are already many different competing products FAR cheaper than $100k. Like down to $500 to $7,000 depending on specifics.
    A final thought on where these are used. Japan farms teeny little patches, imports about 60% of its food! and is the US’s fourth largest export market. On the flip side, we are feeders of the world. You can’t do that with 4 gallon machines.

    1. As an ag pilot in nebraska myself, I couldn’t have said it any better. Often get in the same argument over other drone use in this area. Many people using them for infrared and thermal imaging here, we have a 182 set up with all the ndvi/thermal/nir cameras, they claim they can do it cheaper with a drone but we are at $12 per acre for 6 photos spread out over the growing season. The same principal even applies to the pictures tho, we fly at 2200agl, 1 picture gets a whole quarter, the drones can only fly at 50 or so feet so they make 30 passes and have to stitch the images together, that’s fine for color pictures but if it takes 4 or 5 hours to do that there’s such a temperature difference in crop canopy and ambient air as well as light position from the sun that it makes a huge difference in spectrum from the time they started to the time they stop. Drones are cute little toys to give agronomists something to brag about but when it hits the fan there’s no economical or feasible replacement for the ag plane and pilot. -kick the tires and light the fires, keep the shiny side up. Safe flyin.

    2. George, I found very interesting your comment about UAV crop dusting, but everywhere I look, I see that Japan has been using this method for a very long time.

      WHAT IS DIFFERENT IN JAPAN THAT MAKES IT WORTH ??

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