植保无人机飞行参数对油茶授粉雾滴分布及坐果率的影响

    Effects of the flight parameters of plant protection drone on the distribution of pollination droplets and the fruit setting rate of camellia

    • 摘要: 为了探究植保无人机授粉喷施时对油茶坐果率的影响,该文采用大疆T20型无人机开展授粉试验研究。通过设置植保无人机不同飞行高度和飞行速度,比较分析各试验组的雾滴分布情况,探究植保无人机飞行参数对油茶授粉雾滴分布的影响,以及雾滴分布对油茶坐果率的影响。结果表明:油茶树冠层对于植保无人机喷施的雾滴有较强的阻碍作用;植保无人机授粉喷施的雾滴沉积量随着飞行速度的增加而逐渐减少;随着植保无人机飞行高度增加,雾滴沉积量呈现先升后降的趋势;当飞行速度为3 m/s、飞行高度为2.5 m时,植保无人机授粉效果最好,油茶树上层平均坐果率达到42.67%,油茶树下层平均坐果率为36.00%;油茶坐果率与雾滴沉积量之间呈正相关,斜率K为25.267,修正后的R2为0.806。该研究结果可为植保无人机开展油茶林授粉喷施作业提供重要的数据支撑,为提高油茶产量提供理论依据。

       

      Abstract: Camellia oil plants have been frequently confined to the low fruit-setting rate, due primarily to their inherent physiological properties and the complex growing environment. The fruit-setting rate can subsequently restrict the yield of camellia oil, thereby impeding the progression and expansion of the camellia oil industry. Fortunately, plant protection drones have been widely used for crop pollination in modern agriculture. It is also the promising prospect of plant protection drones in camellia pollination. This present study aims to clarify the effects of drone-assisted pollination on the fruit-setting rate of camellia oil plants. The DJI T20 model drone was also deployed to conduct the pollination trials. A two-factor and three-level experiment was designed to investigate the influence of flight parameters-specifically different flight heights and speeds-on the droplet spraying patterns of plant protection drones. A comparative analysis was then carried out on the droplet distribution across various experimental groups. The fruit-setting rate of camellia oil plants was calculated after post-drone-assisted pollination. Drone flight parameters were also optimized on the droplet deposition patterns for the high fruit-setting rate of camellia oil plants. The optimal volume of droplet deposition was obtained for the significant sway over the fruit-setting rate. Meanwhile, the flight parameters were determined to fully meet the harsh requirements of camellia oil trees. Experimental and analytical techniques were combined to clarify the relationship between drone flight parameters and camellia pollination for the high yield of camellia oil plants. The results demonstrate that the canopy layer of camellia trees posed a significant impediment to the droplets that were sprayed by the plant protection drones. An inverse relationship was observed between the flight speed and the volume of droplets deposited. There was a gradual reduction in the droplet deposition volume, as the flight speed accelerated. Furthermore, an intriguing trend was noted with respect to the flight altitude. The deposition volume of droplets initially exhibited an upward trend, only to decline subsequently, as the operation height of the drone increased. The optimal pollination was achieved, when the flight speed was calibrated to 3 m/s, and the altitude was set at 2.5 m. The average fruit-setting rate reached 42.67% for the upper canopy of the camellia tree, whereas, for the lower sections of the tree was the rate of 36.00%. Statistical analysis revealed a positive correlation between the fruit-setting rate of camellia trees and the volume of droplet deposition, with the slope K of 25.267 and the adjusted R2 value standing at 0.806. Therefore, the feasibility of plant protection drones was verified in the pollination of camellia oil trees. However, there were also some operational nuances. For instance, the resulting airflow was rebounded upon making contact with the ground, if the flight altitude of the drone was set too low. This rebounding airflow was intersected and interacted with the descending airflow, subsequently influencing the trajectory of the droplets during their downward deposition. Such interactions can cause some ramifications on the intended spraying outcomes. Both theoretical and data-driven support was obtained for the application of plant protection drones in the pollination spraying of camellia trees. Some suggestions were also proposed to optimize the subsequent operation of drones in camellia pollination.

       

    /

    返回文章
    返回