AUTHOR=Ou Mingxiong , Zhang Jiayao , Du Wentao , Wu Minmin , Gao Tianyu , Jia Weidong , Dong Xiang , Zhang Tie , Ding Suming TITLE=Design and experimental research of air-assisted nozzle for pesticide application in orchard JOURNAL=Frontiers in Plant Science VOLUME=Volume 15 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1405530 DOI=10.3389/fpls.2024.1405530 ISSN=1664-462X ABSTRACT=This article reports the design and experiment of a novel air-assisted nozzle for pesticide application in orchard. A novel air-assisted nozzle was designed based on the transverse jet atomization pattern. This article conducted the performance and deposition experiments, and established the mathematical model of volume median diameter (D50) and liquid flow rate with the nozzle design parameters. The D50 of this air-assisted nozzle ranged from 52.45 μm to 113.67 μm and the liquid flow rate range from 142.6 ml/min to 1607.8 ml/min within the designed conditions. These performances meet the low volume and ultra-low volume pesticide application in orchard. The droplet deposition experiment results demonstrated that the droplet coverage distribution in different layers and columns are relative uniform, and the predicted value of spray penetration (SP) number SPiA, SPiB and SPiC (i=1,2 and 3) is about 70%, 60% and 70%. The droplet deposit on the foliage of the canopy (inside and outside) uniformly, and bring benefit for plant protection and pesticide saving. Compared with the traditional air-assisted nozzle that adopts coaxial flow atomization pattern, the atomization efficiency of this airassisted nozzle is higher. Moreover, the nozzle air pressure and liquid flow rate is considerably lower and greater than traditional air-assisted nozzle, and these results proved that this air-assisted nozzle has great potential in orchard pesticide application. The relationship between the D50 and nozzle liquid pressure of this air-assisted nozzle differs from that of traditional air-assisted nozzles due to the atomization pattern and process. While this article provides an explanation for this relationship, further study about the atomization process and mechanism is needed so as to improve the performance.