Spray drift from application of plant protection products with drones in vineyards

Field experiments according to ISO 22866 were conducted to determine the spray
drift from Unmanned Aerial Spraying Systems (UASS) applying plant protection
products in vineyards in order to collect data that can be used for drift risk
assessment by regulatory authorities.
Different octocopters, nozzles (standard and air induction), application
parameters (height, speed) and flight patterns (longitudinal and lateral flight lines)
were used. The drift sediment at distances up to 20 m was compared to the German
basic drift values for crewed helicopters and ground based air blast sprayers.
In comparison to PPP applications with crewed helicopters, the spray drift risk is
substantially lower when using UASSs. For air induction nozzles, the 90th
percentile values of drift sediment are even lower than the basic drift values for
ground equipment.
This is why, similar to crewed helicopters, UASSs should be equipped with drift
reducing atomisers, such as air induction nozzles. Providing this, the existing basic
drift values for vineyards would apply also for drift risk assessment for UASS
applications.