小麦不同生育期单旋翼植保无人机施药作业参数优化

Optimization of operation parameters for single-rotor plant protection unmanned aerial vehicle(UAV) at different growth stages of wheat

为确定小麦不同生育期与不同病虫害的单旋翼植保无人机施药作业参数,以CE20型电动单旋翼植保无人机为对象,分别在返青期、齐穗期与盛花期对作业速度、作业高度和喷施流量进行优选试验。经对比分析作业喷幅、雾滴覆盖率变异系数与雾滴穿透率,筛选B5(作业速度4 m/s、作业高度2 m、喷施流量2 L/min)与B9(作业速度3 m/s、作业高度1.5 m、喷施流量2 L/min)为较优作业参数组合。在小麦返青期,当作业参数组合为B5时,有效喷幅为5.75 m,雾滴覆盖率变异系数为26.2%,综合作业效率最高,达36.8 hm2/d。在小麦齐穗期,B5与B9作业参数组合的雾滴穿透率分别为46.7%和60.1%,综合作业效率分别为36.8 hm2/d和26.02 hm2/d;施药前,当小麦蚜数量小于800头/百株时,B5和B9作业参数组合施药后7 d防治效果均为92.37%以上,当小麦蚜数量大于800头/百株时,B9作业参数组合的防治效果高于B5作业参数组合;施药前,当小麦白粉病病情指数小于5.00时,B5和B9作业参数组合施药后14 d防治效果均为81.86%以上,当小麦白粉病病情指数大于5.00时,B9作业参数组合的防治效果高于B5作业参数组合。在小麦盛花期,B5与B9作业参数组合的雾滴穿透率分别为43.8%和55.1%;施药前,当小麦白粉病病情指数小于5.00时,B5和B9作业参数组合防治效果均为86.65%以上,当小麦白粉病病情指数大于5.00时,B9作业参数组合的防治效果高于B5作业参数组合;B5和B9作业参数组合施药后20 d对小麦赤霉病的防治效果差异不大。在小麦齐穗期与盛花期施药参数选择时需结合田间实际病虫害发生情况,当病虫害等级较低时,选择作业效率更高的B5作为较优的作业参数组合,当病虫害等级较高时,选择雾滴穿透性更高的B9作为较优的参数。

In order to optimize the operating parameters of single-rotor plant protection UAV at different growth stages of wheat for control of diseases and pests, CE20 electric single-rotor plant protection UAV was used as the research object, the combinations of commonly used operating parameters(operating speed, operating altitude and spraying flow) were tested and optimized at the regreening stage, the full heading stage and the flowering stage of winter wheat. Through comparing the spraying width, the coefficient of variation of droplet coverage and the droplet penetration rate, B5(operating speed 4 m/s,operating altitude 2 m, spraying flow 2 L/min) and B9(operating speed 3 m/s, operating altitude 1.5 m,spraying flow 2 L/min) were selected as the preferable combinations of operating parameters. At the regreening stage of winter wheat, the spraying width was 5.75 m, the coefficient of variation of droplet coverage was 26.2%, and the daily comprehensive operating efficiency was the highest, up to 36.8 hm2/d when the combination of operation parameter was B5. At the full heading stage, the droplet penetration rates were 46.7% and 60.1%, the daily comprehensive operating efficiency were 36.8 hm2/d, 26.02 hm2/d when the combinations of operation parameter were B5 and B9, respectively. At the full heading stage,when the number of aphids before spraying pesticide was less than 800 per 100 plants, the control efficacy evaluated after seven days were both higher than 92.37% using B5 and B9, when the number of aphids was more than 800 per 100 plants, the average control efficacy after seven days was higher using B9 than that using B5. When the disease index of powdery mildew before spraying pesticide was less than 5.00, the control effect of B5 and B9 after 14 d were both higher than 81.86%. When the disease index was higher than 5.00, the average control efficacy was higher using than that using B5. At the flowering stage, the droplet penetration rates of B5 and B9 were 43.8% and 55.1%, respectively.When the disease index of powdery mildew before spraying pesticide was less than 5.00, the control efficacy was higher than 86.65% using either B5 or B9, and when the disease index was higher than 5.00,the average control efficacy using B9 was higher than that using B5. The control efficacy for wheat scab evaluated 20 d post-application showed little difference between using B5 and using B9. Therefore, the selection of pesticide application parameters at full heading and flowering stage should take the level of pests and diseases into consideration. When the occurrence level of pests and diseases was low, the B5 parameter combination with higher operation efficiency should be selected, and the B9 parameter combination with higher droplet penetration should be selected when the occurrence level of pests and diseases was high.