| There are many kinds of pests in cotton field,the harm is serious,and there is an increasing trend year by year.The control of cotton pests mainly depends on chemical control,there are many problems in traditional pesticide application equipment in cotton fields,such as damage to the fruiting branches,low operational efficiency,low operation efficiency,poor atomization effect,and low utilization rate of pesticide solution.In view of the problems existing in cotton field application,this study combined with the emerging aviation plant protection technology,carried out plant protection unmanned aircraft application technology research in different growth stages of cotton field.The effects of application parameters of plant protection UAV on the deposition distribution of cotton canopy droplets,pesticide utilization control effect of cotton aphid and spraying effect of defoliant were tested.The main results are as follows:（1）The effects of cotton seedling height,spraying amount,pesticide type and additives on the cotton field operation effect of plant protection unmanned aircraft were clarified.The results showed that the operation height（1.5 m and 2.5 m）had no obvious effect on the droplet deposition distribution and pesticide utilization rate of Quanfeng electric UAV and oil-powered UAV on cotton.At the operation height of 1.5 m,Quanfeng electric UAV had the highest control effect,reaching 79.90%.The droplet density and droplet coverage increased with the increase of spray volume in the range of 15～30L·hm-2,the spraying amount of 22.5 L·hm-2 had the highest control effect on cotton aphid,reaching99.05%.Adding adjuvantde had no obvious effect on droplet deposition distribution,but could improve the control effect on cotton aphid.Dajiang electric UAV spraying acetamiprid to add Betatong the highest prevention effect,99.28%.（2）The droplet deposition distribution characteristics and pesticide utilization rate of unmanned aerial vehicles with different types at flowering and bolling stages of cotton were clarified.The results show that the spray droplet deposition effect of the electric UAV is better than that of the oil UAV,and the appropriate operating heights of different UAVs are different.Dajiang electric UAV operating height of 1.5,2.5 m,can achieve better operating results,and the droplet density in the upper part of cotton canopy reaches 115.69±9.06·cm-2、131.48±16.5·cm-2respectively,and in the middle reaches 85.6±4.52·cm-2、83.17±9.52·cm-2.The operation effect of Quanfeng 3WQFZP-10 and Jifei 3WWDZ-15UAV at 1.5 m operation height is better,and the droplet coverage is 11.66%and 10.71%respectively.Hanhe 3WYD-4-16 UAV is suitable to operate at 2.5 m height,and the droplet coverage rate is 9.21%.After droplet coverage rates of DJI UAV spraying increased by 10.92%and 5.63%respectively after the addition of auxiliary Beidatong and Nongjianfei,and the droplet coverage rates of extreme flight UAV spraying increased by 3.28%and 5.08%respectively.The addition of auxiliary was beneficial to improve the droplet deposition effect and pesticide utilization rate,and had no obvious effect on droplet density.（3）The deposition and distribution of pesticide solution in cotton canopy and the influence of additives on the defoliation and ripening effect after spraying defoliant on different types of plant protection unmanned aerial vehicles at boll opening stage were clarified.From the test results of UAV single spray width droplet deposition distribution,the droplet particle size of the sampling points near the center of the two UAVs route is relatively uniform,while the particle size on both sides away from the route is smaller,and the droplet particle size of most sampling points is in the range of 100～300μm,and the pesticide has good penetration in the cotton canopy.The droplet density of Jifei UAV in cotton canopy was 51.83～80.04·cm-2,and that of Dajiang UAV was 35.64～43.36·cm-2;With the addition of Nongjianfei and Betatong additives,the defoliation effect of Jifei UAV on cotton increased by49.51%and 36.52%,respectively,and that of Dajiang UAV increased by 0.68%and 4.11%,respectively. |
PDF Full Text Request