Increasingly, Farmers are Using UAVs to Spray Pesticides

UAV spraying is effective tool for applying pesticides on crops. UAVs especially shine when fields are flooded with water, making entry of motorized vehicle to the field impractical or when treating crops that grow in steep hills.

UAV pesticide spraying is becoming increasingly available for specialty crops and row-crop production. Recently, UAV manufacturers such as DJI have started offering high payload rotor UAVs that include sprayers.

Spraying with UAVs is a unique practice since it is conducted autonomously. UAV sprayers are equipped with almost all the parts of any other sprayer: a tank, a pump to push liquid through the hoses to the nozzles, filters and a pressure gauge. But there are limitations, mostly on the size of these components because of the power required to keep the UAV sprayer in flight mode for a reasonable time.

UAVs carry unique characteristics when applying liquid products. First, the application is different from ground-based machines but not the same as typical aerial applications completed with helicopters or crop dusters. These small UAVs are typically flown 3 to 10 feet above the crop or target area with their rotors creating turbulence or what we call vortices. While the turbulence created by the rotors can help spray droplets penetrate into a crop canopy and provide good coverage on the top and bottom of leaves, these vortices cause drift concerns. Research is being conducted to determine spray deposition, coverage and drift from UAV sprayers in comparison to other methods used for pesticide application. Unique features for UAV sprayers include vertical or altitude adjustments for topography or height, autonomous swath control, and safety.

In general, spray UAVs for applying products to row-crops will have 4 to 5-gallon tanks with a spray width between ranging 10 and 15 feet. The application rate will be 1 to 2 gallons per acre or set in accordance with product labels. Today, multi-rotor UAVs have a flight time of around 15 – 20 minutes allowing a tank to be dispersed before needing to land to refill plus change out batteries for the next flight. Most manufacturers provide estimates on application rates in minutes per acre with most UAVs spraying an acre within 3 to 4 minutes.

YAMAHA RMX

UAVs can be used to clean up fields, spray drowned out spots, control resistant weed escapes, or other small areas within a field versus using a high-clearance sprayer.

Today, the mapping process is more accurate and efficient given the development of AI representing an essential step forward in technology.

Companies developing and testing these systems have been successful in applying to the FAA for an exemption under Section 333 resulting in the FAA potentially issuing a Certificate of Waiver or Authorization (COA for Certificate of Authorization) to facilitate testing in the United States.

Farmers and ranchers can purchase spray UAVs today but, at a minimum, you will need following three licenses to operate:

  1. Private Pesticide Applicator License
  2. Part 107 Certificate from the FAA
  3. Part 137 Certificate from the FAA

Must also Register UAV with the FAA

  • Small to Medium UAVs– Registering any UAV between 0.55 and 55 pounds is rather quick and painless. Click HERE for an article explaining the registration process in greater detail.
  • Large UAVs– Registering a UAV larger than 55 pounds with the FAA is complicated and time consuming. A large UAV must be registered under Rule 47. Click HERE for a detailed article explaining the registration process.

Large UAVs in the Marketplace

  1. Yamaha RMAX and FAZER
    • 2 o4 4 stroke gas engine, depending on the model
    • 6.3, 4.2, or 8.5 on-board storage (2 tanks) depending upon model
    • 0.3 to 0.5 pgm discharge rate
    • Granular material application option
    • Legal in CA to apply crop protection products.
  2. DJI AGRASMG
    • Electric motor with 8 rotors
    • 2.6 gallon storage tank
    • Spray with of 4 – 6 meters
    • 4 nozzle boom
  3. Hylio AgroUAV
    • Electric motor with 8 rotors
    • 4.5 gallon storage tank
    • 1 gpm discharge rate
    • 15 foot spray width
    • 6 nozzle boom

While there is still work on application quality, spray UAVs provide unique capabilities over manned aircraft and ground spraying equipment. To learn how we can help you register your UAV then contact the Unmanned Aviation Systems Law Center at 623-252-6884 or message us HERE.