Location: Aerial Application Technology Research
Project Number: 3091-22000-036-04-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2018
End Date: Sep 30, 2019
To generate data for development of a model to be used to estimate exposure values to assess risk from air blast spraying. Measurements will be made to facilitate the assessment of drift as related to key meteorological, application, and cropping systems. The deposition results will be used to build an orchard air blast deposition simulation model for use in regulatory risk assessment and spray drift management programs.
This project will be part of a larger ARS project related to the development and validation of aerial and air blast spray transport models to be used for regulatory risk assessment and drift management. ARS scientists are investigating the role sprayer operational characteristics, cropping systems, and meteorology play in the transport and fate of spray applied in orchards and vineyards. With air blast sprayers, the spray is released within the orchard or vineyard lateral to the target canopy rather than above it. The meteorological conditions within the orchard (i.e. wind speed, wind direction, turbulence, relative humidity, etc.) as well as the vegetative density will be measured as part of this work. As this is a complex system, the vertical distribution of spray within the canopy will be measured using a variety of natural and artificial sampling media with a fluorescent dye used as a tracer. Additionally, drift sampling will be conducted at varying distance downwind of the application site. The focus of this project will be spray application in a vineyard. Two specific scenarios will be evaluated. The first will sample out to 2400’ downwind in rangeland to assess potential for long range drift from air blast sprayers. The goal for this portion is to complete seventeen replicates along with 3 blanks. The second scenario will examine the effects of moving the sprayer to different rows within the vineyard. A total of 20 tests will be conducted. One set of tests will consist of the sprayer making application in the second row of the vineyard (all row numbers defined as upwind of the downwind edge). Another set of tests will be conducted with the sprayer operation on the fourth row, another set of test with spraying the sixth row and another the eighth row. Three blank trials will also be conducted. Meteorological monitoring stations will be located at a central location and inside the orchard and approximately 60 ft upwind from the application area. Air temperature, air flow, and relative humidity will be measured at above ground heights of 3, 6, 10, and 30 ft on the tower outside the orchard. Inside the orchard these measurements will be taken at 3 ft, half the height of the orchard, orchard canopy top and twice the orchard height.