Evaluation of spray drift in apple orchards of Trentino: comparison of different solutions to reduce environmental contamination

The main characteristics of the agricultural scenery of Trentino, Italy, are: intensive orchards closely connected with inhabited areas, recent renewal of most old plantings with modern ones consisting of dwarfing rootstock trees with a height of up to four meters. Based on these features an experimental investigation is on-going into drift management in apple orchards in the province. Comparative tests were carried out in different wind conditions in an apple orchard using 1) a standard axial sprayer equipped with ATR swirl nozzles; 2) an on-target tower sprayer with anti-drift air injector nozzles; 3) a handheld lance. Results have been compared to establish the average degree of mitigation achievable by each type of equipment and how this is affected by wind conditions. The most appropriate equipment to adopt in the Trentino mountain growing context seems to be the on-target sprayer with anti-drift air injector nozzles. Considering the instability of wind conditions during treatments, to ensure the maximum level of drift reduction, further experiments are needed to find other technical approaches which may be combined with the spray equipment already tested