Abstract:Aiming at the problem that the space between ridges in cigar tobacco fields is small due to the tall plants and the growth of leaves, and the production of cigar tobacco leaves requires high color and integrity of tobacco leaves, and the field management requirements cannot damage tobacco leaves, which leads to the difficulty in plant protection of middle and lower tobacco leaves in cigar tobacco plants during production. Combined with the growth characteristics of tobacco leaves, a plant protection device for middle and lower layers of tobacco leaves in cigar plants was designed. The device mainly consisted of a spray system, a crawler chassis and a control system and other functions. In order to obtain the growth characteristics of tobacco plants, a three-dimensional laser scanner was used to scan them and establish a spatial distribution model of plant leaves in the field. According to the distribution characteristics of tobacco leaves in the field, the overall structure and working mode of the device were determined; combined with the tobacco leaf shape characteristics and plant protection and agronomic requirements, the structure design and analysis of the spraying system were carried out, and the parameter range was determined. According to the requirements of field operations, the dynamic analysis of the crawler chassis and the design of the control system were carried out. The field experiments was carried out, and the parameters of the spray system were optimized by using Box-Behnken. When the spray pressure was 0.65MPa, the nozzle angle was 20.4°, and the nozzle aperture was 0.4mm, the vertical direction of the cigar leaf layer was simulated by the vertical droplet distribution measuring instrument. The liquid adhesion performance test showed that the vertical distribution of droplet deposition met the requirements of cigar tobacco leaf plant protection. The field experiments results showed that the coverage rate of the liquid medicine on the front side of the middle and lower layers of the cigar plant was 52%~83%, and the coverage rate of the backside was 22%~45%, which can realize the effective spraying of the liquid medicine on the middle and lower layers of the tobacco leaves of the cigar plant.
