In order to explore the equivalent static condition of the impact damage of the Korla fragrant pear under free fall, the Korla fragrant pear was chosen as the research object in this paper, and the height of free fall and rebound were recorded by a high-speed camera to obtain the impact damage energy of the fragrant pear. In addition, a mechanical compression test was conducted on the fragrant pear to obtain its static deformation energy, and the equivalent static condition of the impact damage was calculated based on the mechanical energy conservation formula using the damage volume of the fragrant pear as the evaluation standard. The test verification was carried out on the damaged fragrant pear using a scanning electron microscope test. This study showed that the falling and rebound height of the fragrant pear within the range of the test parameters and under the free fall test conditions conform to linear fitting. The coefficient of determination (R²) was 0.9951, and the impact damage occurred when the corresponding energy reached 205.89 × 10⁻³ J. When the damage energy was within 203.4 × 10⁻³ J and 498.23 × 10⁻³ J, the static damage volume of the fragrant pear was linearly correlated to the impact damage volume, R² was 0.9944, and the maximum deviation between the predicted damage volume and the actual damage volume of the fragrant pear in the verification test was 4.4%. These data can provide a reference for research on the equivalent method of impact damage of the Korla fragrant pear, and provide theoretical guidance to the fruit industry to reduce damage and increase efficiency.

A multi-duct orchard sprayer is designed in this paper to address the problem of low droplet coverage during plant protection in walnut orchards in South Xinjiang, China. This spray comprises a base frame, a pesticide tank, an air delivery system, a copying base frame and a drive system. Effects of the sprayer structure on the flow field were simulated using computational fluid dynamics. Operation parameters were optimised using the response surface analysis and validated using a field test. The results demonstrated that five jet tubes in the simulation design could fulfil the design requirements of GB/T 32250.3-2022. The upper, middle and lower droplet coverages were 74.92%, 90.01% and 69.9%, respectively, when the sprayer’s advancing speed, the angle of jet tubes and the nozzle diameter were 0.53 m/s, 70.27° and 0.81 mm, respectively. The machine can effectively enhance the spraying efficiency and droplet coverage of each canopy during plant protection operations in the new walnut orchards of South Xinjiang, China, and provide references for designing and optimising fruit tree spraying machinery.