Advanced spraying systems to improve pesticide saving and reduce spray drift for apple orchards

New spraying systems embedded with different technologies have been developed for pesticide application in 3D crops. However, while applied to specific tree crops, the potential spray drift mitigation for advanced spraying systems needs to be classified due to the great variability of spray equipment and canopy structure. Here a precision spraying system was developed and compared with two typical spraying systems (conventional system, optimized system following the best management practices) for the applied volume/pesticide and spray drift in an apple orchard at two growth stages following the ISO22866-2005 protocol. Compared to the conventional system, the other two advanced systems significantly reduced the amount of ground drift (>60%) at most of the sampling distances at the growth stage BBCH 72, while the precision system demonstrated the best drift mitigation (57.3% reduction) at the stage BBCH 99. For the airborne drift, a remarkable drift reduction was also achieved with the two advanced systems. Specifically, the optimized spraying system exhibited a drift reduction by approximately 80% at the first growth stage, and the precision application demonstrated its considerable advantages in minimizing drift loss for the sparse canopy at the stage BBCH 99. Moreover, the saving of applied volume/pesticide was achieved by 12% with the optimized system and 43% with the precision system. This study revealed the necessity and prospect of the advanced spraying systems to reduce the environmental contamination and health risk from pesticide applications in fruit tree production.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 773718 (OPTimised Integrated pest Management for precise detection and control of plant diseases in perennial crops and open-field vegetables, www.optima-h2020.eu). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Peer ReviewedPostprint (published version

Use of ultrasound anemometers to study the influence of air currents generated by a sprayer with an electronic control airflow system on foliar coverage. Effect of droplet size

Air assistance and droplet’s characteristics influence on the pesticide deposit and its distribution over the intended target during the spray application process. The present research work is focused on the characterization of the leaf coverage and the overall spray distribution within the whole canopy by combining different settings of air assistance with different nozzles, generating different droplet’s sizes. A new designed air-assisted orchard sprayer was tested, presenting a wireless remote-regulation system to control the airflow rate from the fan by adjusting the blade pitch. In this way, five airflow rates were obtained by combining the gearbox position and the blade pitch. For each one of these five air settings, three droplet sizes (F-Fine, M-Medium, and C-Coarse) were combined and evaluated over a set of artificial apple trees.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 773718 (OPTimised Integrated pest Management for precise detection and control of plant diseases in perennial crops and open-field vegetables, www.optima-h2020.eu). Bernat Salas received funding for his Ph.D. development from Agència de Gestió D'Ajuts Universitaris I de Recerca (AGAUR) (file N° FI_B 01193)Postprint (updated version