USDA-Bayer Collaboration

Daniel Martin (1), Jane Tang (2), Yaning Yang (2), Brad Fritz (1), Greg Kruger (3), Trenton Houston (3)​

1 United State Department of Agriculture, Agricultural Research Service (USDA-ARS), Aerial Application Technology Research Unit, College Station, Texas​

2 Bayer Crop Science​, Environmental Safety, St. Louis, Missouri

3 University of Nebraska-Lincoln​, Lincoln, Nebraska

Primary Contacts: Daniel Martin ( and Jane Tang (


Pesticide drone application regulatory scenarios are complex, and the relevant label and regulatory data requirements are under development among regulatory agencies. Regulatory authorities are considering the need to adapt current regulatory systems for drone applications.

Bayer Crop Science partnered with USDA-ARS Aerial Application Technology Research Laboratory to conduct a non-GLP spray drift field study at the University of Nebraska at Lincoln West Central Research and Extension Center in October 2020. The goal of the study was to characterize drone application spray drift by comparing it with a spray drift from ground application.

The study protocol was developed with input from United States Environmental Protection Agency and Canada’s Pest Management Regulatory Agency. Data collected from this study will be helpful to address potential regulatory needs and better understand the drift potential of drone applications and encourage research work to develop common protocols for future drone study.

This webpage is designed to provide a detailed description of the experimental design and approach used in the study. Data resulting from the study is still under review and will be published in a peer-reviewed journal.  

Experimental Design
  • Four treatments with 12 replications per treatment (Randomized in trial)
    • 2 Spray Platforms (Tractor and RPAAS)
    • 2 Spray Nozzles TT110-01 (Medium) and TTI110-01 (Coarse)

Except for the spray platform and release height, other spray parameters such as nozzle operating pressure, application rate, and effective working width (swath) were the same for drone and ground application using the same nozzle type.


These videos show actual spray application of water containing the fluorescent dye PTSA (1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt) during this spray drift characterization study. The desired wind conditions at application were 3 to 10 MPH with a limit of 15 MPH as 3-min average. These conditions were verified using on-site weather stations. These videos show only one of twelve replicate applications which were conducted per treatment. Therefore, twelve separate applications with RPASS using the medium nozzle and twelve with the coarse nozzle, and twelve each for the ground sprayer. For each replicate, all of the deposition and drift samplers were collected, and new samplers were installed. These replicates were conducted in a randomized fashion rather than in order to remove any bias with variable environmental conditions over the course of the study.

Video of ground sprayer application filmed by a drone operated on site:


Video of RPAAS application filmed by a second drone operated on site:


Video of RPASS application taken from camera on-board the RPASS: