What to be considered when you buy a new sprayer? : guideline for stakeholders : demands on a modern environmental sprayer / this document has been compiled by the SPISE Technical Working Group 1 ; authors: Emilio Gil (Universitat Politecnica de Cataluña, Spain), Christoph Schulze-Stentrop (Hardi Internatinonal, Denmark) ; publisher: Julius Kühn Institute - Federal Research Centre for Cultivated Plants