A Method to Determine Spray Drift Potential from Nozzles and its Link to Buffer Zone Restrictions

摘要

German Federal Biological Research Centre for Agriculture and Forestry Braunschweig (BBA) established a system to adjust buffer zone restrictions according to application conditions. Part of this system is the official list of loss reducing equipment, where spraying systems are categorized in classes of at least 50%, 75% and 90% spray drift reduction. This is normally proved by field tests. A method is presented that enables an evaluation of agricultural atomizers concerning spray drift potential. Single nozzles are tested in a wind tunnel. A Drift Potential Index (DX) is calculated from parameters of vertical drift concentration in a section 2 m downwind from the nozzle. The DIX value is used to classify sprayers equipped with that nozzle regarding spray drift potential in relation to a conventional flat fan reference nozzle 03 at 3 bar spray pressure. This reference corresponds to the basic drift values from field drift measurements.Buffer zone restrictions for a pesticide can be defined by BBA according to application conditions as drift reduction, kind of surface water and vegetation next to the field. The user has to follow these restrictions corresponding with actual conditionsduring application.