Investigations on spray drift mitigation by means of artificial barriers in high tunnel strawberries

This paper summarises the results of some trials carried out to verify the capability of artificial barriers to mitigate spray drift when treating soft fruits, particularly strawberry, cultivated under high plastic tunnel and treated by cannon sprayers. The possibility to protect plants and their production from atmospheric agents is one of the main reasons for the wide adoption of plastic tunnel in soft fruit cultivations. The protective structure can often integrate a series of tools like anti-insect nets or plastic sheet closures that can help to mitigate drift during spray applications by filtering the airflow mixed with small droplets and catching those prone to drift. Preliminary trials showed the capability of the net to reduce the amount of liquid deposited behind it. Spray application trials in high tunnels showed that drift mitigation is possible when using different types of barriers, but a lower effect can be expected for the anti-insect net and up to almost complete drift reduction with a plastic film. The results of spray deposition in the strawberry canopy could not show a clear effect of interference between the artificial barrier and the mix of airflow and droplets