AUTHOR=Dou Hanjie , Li Qi , Zhai Changyuan , Yang Shuo , Zhao Chunjiang , Gao Yuanyuan , He Yakai 

TITLE=Computational model of pesticide deposition distribution on canopies for air-assisted spraying

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1153904

DOI=10.3389/fpls.2023.1153904

ISSN=1664-462X

ABSTRACT=The deposited pesticide distribution in fruit tree canopies is key for evaluating the efficacy of air-assisted spraying in orchards. Most existing studies have determined the impact of pesticide application on pesticide deposition on canopies without the use of a quantitative computational model. In this study, an air-assisted orchard sprayer with airflow control was used to perform spraying experiments on artificial and peach trees. In the spraying experiment on an artificial tree, a canopy with leaf areas ranging from 2.54 m2~5.08 m2 was found to require an effective air speed of 18.12~37.05 m/s. The canopy leaf area, air speed at the sprayer fan outlet and spray distance were used as test factors in a three-factor five-level quadratic general rotational orthogonal test to develop a computational model for pesticide deposition at the inner, outer and middle regions of a fruit-tree canopy with R2 values of 0.9042, 0.8575 and 0.8199, respectively. The results of a significance analysis were used to rank the influence factors for the deposited pesticide distribution in decreasing order of significance as follows: the spray distance, leaf area and air speed for the inner region of the canopy and the spray distance, air speed and leaf area for the middle and outer regions of the canopy. The results of the verification test conducted in a peach orchard showed that the computational errors of the pesticide deposition model for the inner, middle and outer regions of the canopy average were 32.62%, 22.38% and 23.26%, respectively. This study provides data support for the evaluation of the efficacy of an air-assisted orchard sprayer and the optimisation of the sprayer parameters.