Air flow characteristics – proposed as mandatory requirement for airblast sprayers

Introduction The biological efficacy and environmental safety of pesticides application is worldwide more and more restricted. In European Community of 28 countries (EC28) since 2009 the Directive 2009/128/EC required governmental control of Plant Protection Products (PPP) use (Czaczyk 2010). According that since beginning of 2014 an Integrated Pest Management (IPM) was int-roduced as mandatory part of Integrated Plant Production (IPP). In EC28, according to this re-quirements, mandatory technical control of sprayers should be introduced till December 2016. The technical requirements concern new sprayers, and also sprayers in use. Usually orchard and vineyard sprayers are equipped with air fan. It generate air flow for trans-portation of generated spray droplets of tank mix to the target. From different sources is known, that the air flow characteristics also at the same type (from the same manufacturer) of airblast sprayers is significant different (is not reproducible) (Triloff 2005, Triloff 2014). The vertical liquid distribution from airblast sprayers strong depends on an air flow characte-ristics Hewitt 1993, Czaczyk 2012, Fritz et al. 2014). Because the air flow is invisible, it is di-fficult to evaluate its characteristics. According to new requirements for environmental safety of PPP application, the parameters influenced liquid distribution should be used to improve of the sprayer working quality. With aim to identify this problem, four different orchard sprayers with axial fun produced in Poland were tested. The non symmetric airflow characteristics were documented. It depends on the fan construction and also on rotational speed of propeller. According to the different air characteristics also liquid vertical distribution is influenced, and the changes of the target coverage and drift potential should be described by the manufacturer.