Driftmetingen H.S.S.-CF dwarsstroom boomgaardspuit met Intelligent Spray Application (I.S.A.) systeem, GNSS en taakkaart bespuiting

With the H.S.S. CF orchard sprayer and Intelligent Spray Application (I.S.A.); a precision cross-flow fan orchard sprayer equipped with sensors for green leaf detection and Pulse Width Modulation (PWM) functioning nozzles for precise and variable dosing and a satellite navigation system (GNSS) to spray individual trees on a task-map; Wageningen UR performed spray drift experiments following the Dutch TCT and ISO22866 protocols. Measurements were done in comparison with a reference spray technique (Munckhof cross-flow fan sprayer with Albuz ATR lilac nozzles at 7 bar spray pressure). Spray drift experiments were done in the 2019 (August – November) and 2020 (June-July) growing season spraying the downwind 8 rows of an apple orchard. Applications were done in eight periods in the full leaf stage of the apples (BBCH 75-91). The H.S.S. CF I.S.A. was equipped with 75% drift reducing nozzles (Lechler IDK 90- 015 C at 3 bar spray pressure) and the air assistance was set in a low setting using the fan at 1400 rpm) spraying of the outside tree row one-sided. The task-map defined that the individual trees were alternatingly sprayed or not sprayed. Fan speed was controlled and recorded by the H.S.S. Drift Control box. Because of the construction of the sprayer the fan does not take up any spray liquid and does not blow it out at the side where the nozzles are switched off. Results of the spray drift experiments are used to quantify spray drift reduction of the H.S.S. CF I.S.A. precision cross-flow fan orchard sprayer equipped with PWM modules at the nozzle bodies, Lechler IDK 90- 015 C flat fan venturi nozzles (75% drift reduction), low air setting (1400 rpm fan) and green leaf detection sensors and single-sided spraying of the outside tree row spraying. To quantify the spray drift reduction the spray drift deposition at 4.5-5.5 m from the last tree row of the H.S.S CF I.S.A. GNSS/task-map and its settings is evaluated against the spray drift deposition of the reference spray technique; showing spray drift reduction was 99,0%. The H.S.S. CF I.S.A. with GNSS/task-map can for the above-mentioned settings be classified in the spray Drift Reducing Technology (DRT) class DRT99. Measurement of airborne spray drift averaged over 0-10 m height at 7.5 m distance from the last tree row resulted in a spray drift reduction of 97.6% when spraying with the H.S.S. CF I.S.A. with GNSS/task-map.