无人机与人工喷施雾滴在水稻冠层内沉积特征及效益比较

[目的]旨在阐明无人机和人工喷施雾滴在水稻冠层内沉积分布特征,比较其稻瘟病防效、水稻产量及经济效益.[方法]选用电动四旋翼植保无人机,设置3个不同飞行高度和3个不同施药量,于孕穗期观测喷施雾滴在水稻冠层内沉积分布状况,并和人工喷施处理防治稻瘟病的效果、产量及经济效益进行比较.[结果]雾滴沉积量随飞行高度的升高而减少,雾...     

不同植保机械喷施雾滴在水稻冠层沉积分布规律及对病虫害防效比较

[目的]为阐明无人机与地面植保机械喷施雾滴在水稻冠层的沉积分布特征,比较其对不同冠层病虫害防治效果,科学推广及使用植保机械.[方法]采用雾滴沉积分布检测、利用率测定以及田间调查等方法,研究6种不同植保机械在水稻田喷雾后雾滴在冠层的沉积分布、利用率以及对纹枯病和稻纵卷叶螟的防治效果.[结果]3种无人飞机喷施雾滴在水稻冠层...     

植保无人机飞行高度与方向对棉田雾滴沉积分布的影响

为了探究植保无人机喷施作业飞行高度和方向对雾滴沉积分布的影响,通过设置3WQF120-12型智能悬浮植保机的飞行高度和方向研究了不同喷雾作业参数对棉田雾滴沉积的影响。用10 g·L－1诱惑红溶液代替农药在棉田进行喷洒,保持5 m·s－1的飞行速度不变,改变无人机作业高度和飞行方向进行喷雾;通过雾滴测试卡进行采样,对雾滴采集卡进行图片扫描,并采用图像处理软件DepositScan分析各处理的雾滴密度、覆盖率及雾滴粒径大小等参数。结果表明,在植保无人机作业速度保持为5 m·s－1的条件下,飞行作业高度为1 m时,雾滴在棉株上的沉积效果较好,且正向飞行试验的雾滴沉积效果优于逆向飞行。在棉田雾滴的沉积效果受到高度和方向共同作用的影响,同时环境风向和风速也是影响雾滴沉积的重要因素。     

大载荷植保无人机施药参数优选及不同药剂对橡胶树“两病”的飞防效果研究

本研究利用大载荷油动植保无人机(FBH300T)开展橡胶树白粉病和炭疽病(简称橡胶树“两病”)的飞防试验，分析飞行离冠层高度3、5、7 m和施药量60、90、105 L/hm²两个参数对橡胶树上、下层叶片雾滴沉积分布的影响。发现飞行高度和施药量对雾滴密度和雾滴覆盖率均表现出极显著的影响，筛选出飞行离冠层高度5 m、施药量90 L/hm²、飞行速度5 m/s是该机型的最优施药参数。利用兼治橡胶树多种叶部病害的新型专用药剂19%保叶清微乳剂，以及60%硫磺粉悬浮剂、45%戊唑·咪酰胺水乳剂和50%硫磺·三唑酮悬浮剂等高效药剂与大载荷植保无人机配套施用，分析各药剂单独和两两混配施用对橡胶树“两病”的飞防效果。结果表明：4个单剂中对白粉病防效最好的是50%硫磺·三唑酮悬浮剂，其次是19%保叶清微乳剂；对炭疽病防效最好的是19%保叶清微乳剂，其次是45%戊唑·咪酰胺水乳剂。药剂两两混配施用下，19%保叶清微乳剂和60%硫磺粉悬浮剂按1∶1混配对白粉病和炭疽病的防效最好，其次是19%保叶清微乳剂和50%硫磺·三唑酮悬浮剂按1∶1混配。本研究结果可为橡胶树...     

喷施参数对四旋翼植保无人机雾滴在橡胶林中分布的影响

雾滴分布特征影响作物上喷雾的施药效果,而喷施参数是影响植保无人机雾滴分布特性的重要因素之一。为了揭示施药量和雾滴粒径等喷施参数对电动四旋翼植保无人机雾滴在高大乔木橡胶树林段中分布的影响,以成龄‘热研7-20-59’胶林为试验地,分别设置18.75、37.50、75.00、90.00、105.00 L/hm²施药量,70、100、150、250 μm雾滴粒径,采用5点采样法在6个高度上测量水平方向及垂直方向的雾滴谱宽度、雾滴覆盖密度、雾滴分布均匀度等主要作业质量技术指标数据,结合橡胶树白粉病的防治效果,筛选四旋翼无人机的最佳喷施参数。结果表明,随施药量的增加,雾滴谱宽度呈下降趋势,雾滴覆盖密度显著增加;施药量在75 L/hm²及以上时满足最低施药雾滴覆盖密度的要求。随着雾滴粒径的增加,雾滴谱宽度呈上升趋势,雾滴覆盖密度无显著差异,雾滴粒径100 μm的水平分布均匀度最优。不同施药量和雾滴粒径的雾滴在橡胶林垂直方向的分布均匀度一致,穿透性良好。本研究筛选出施药量75 L/hm²和喷雾粒径100 μm的最佳喷施参数,在橡胶树白粉病最佳防治时期使用咪鲜胺（EW）和戊唑醇（SC）复配药剂进行田间飞防试验,效果优异,2块试验地的防效分别为65.7%和82.9%。本研究提供了一组橡胶树白粉病防治的四旋翼无人机施药参数,为植保无人机在橡胶林病虫害防治作业中提供参考。     

灌浆期六旋翼无人机喷幅和喷液量对玉米群体内雾滴沉积分布、漂移特性的影响

采用大疆T30无人机在玉米灌浆期进行喷施作业,探讨喷幅和喷液量对雾滴在群体内沉积分布影响。采用两因素试验设计,设置3个喷幅[4(G1)、5(G2)、6.5 m (G3)]和5个喷液量[15、30、45、60、75 L/hm²(R1～R5)],将玉米群体从上至下分为5层(A～E)。结果表明,在不同喷幅和喷液量处理组合下,随着喷液量增加,雾滴总沉积量、覆盖率、覆盖密度显著增加,随着喷幅的升高呈先增后降的趋势,其中G2R5、G3R5和G1R5处理的雾滴总沉积量较大,但雾滴的地面损失量增多、沉积量均匀性和穿透性不佳、漂移加重,总体上G2喷幅下各叶层的雾滴沉积分布较优。在实际生产中喷液量选择不宜过大,应结合施药属性及农田环境等因素,确定适宜的喷液量。     

茶园应用植保无人飞机的可行性评价

为评估植保无人飞机在茶园应用的可行性,在茶园测试了无人飞机施药的雾滴沉积分布、对小贯小绿叶蝉(Empoasca onuki)防治效果,以及6种农药在茶叶中残留量.结果表明,供试的无人飞机喷雾喷头、飞防助剂对无人飞机喷雾的雾滴沉积分布影响不显著.无人飞机施药的雾滴大小、雾滴密度、沉积量等均优于背负式电动喷雾器,但无人飞机...     

助剂对无人机喷施棉花脱叶剂作业效果的影响

采用极飞3WWDZ-15A多旋翼植保机喷施棉花脱叶剂“棉田阔笑”（540 g·L^－1噻苯隆·敌草隆悬浮剂）,通过布置雾滴测试卡研究了雾滴在棉花冠层的沉积分布情况,结合田间脱叶催熟效果调查及棉花纤维品质检测,研究了烷基乙基磺酸盐、农健飞和倍达通3种助剂对棉花脱叶催熟效果、棉花产量主要构成因素和纤维品质指标的影响。结果表明：采用无人机喷施脱叶剂,雾滴沉积分布满足脱叶剂施药要求。添加助剂的3个处理药后30 d脱叶率达到85.53%～100%,显著高于未添加助剂的处理。添加农健飞、倍达通助剂处理的棉花吐絮率分别为66.22%和60.73%,显著优于未添加助剂的处理。助剂对棉花铃重和衣分及纤维品质主要指标无不利影响。     

水稻喷雾技术与水稻株型冠层关系研究综述

低容量喷雾、航空喷雾、静电喷雾及精准喷雾等多种喷雾技术的融合和变革,是现代农业发展中水稻喷雾技术发展的必然趋势,而靶标特点、作物株型、作物生长时期是影响喷雾技术发展的关键问题。株型及冠层结构参数(叶面积指数、叶倾角、株高等)是影响水稻冠层雾滴行为的关键因素。因此,结合喷雾技术和株型及冠层结构参数研究雾滴传输及沉积是深入研究水稻冠层雾滴行为的出发点及重要方向。     

植保无人机在阜阳市的发展应用

随着土地流转等规模化种植的发展和农药减量增效政策的推动,植保无人机等高效植保作业装备发展迅猛,在农作物上的应用范围也越来越广。该文通过统计近5年来植保无人机在阜阳市的购置、分布及应用现状,结合农业生产实际,分析植保无人机在阜阳农业作业中优势与局限,并针对如何提高植保无人机技术水平进行分析,以期为植保无人机更好服务于阜阳市智慧农业发展提供参考。     

Droplet deposition and control effect of insecticides sprayed with an unmanned aerial vehicle against plant hoppers

A small unmanned aerial vehicle (UAV) that can spray pesticide with high efficiency and with no damage to crops is required for the timely and effective spraying of small fields and/or those in hilly mountains. The current study aimed to illuminate the influence of spraying parameters, such as operation height and operation velocity, of the UAV on droplet deposition on the rice canopy and protection efficacy against plant hoppers. Droplets of 480 g l⁻¹ chlorpyrifos·(Regent EC) (at a dose of 432 g a.i. ha⁻¹, spray volume rate of approximately 15 l ha⁻¹) were collected using water-sensitive paper, and the coverage rates of the droplets on the rice canopy and lower layer were statistically analyzed. The deposition and distribution of droplets in the late stage of rice growth were closely related to the operational height and velocity of crop spraying as executed by the UAV, further affecting insect control. The spraying parameters for preventing plant hoppers were then optimized. When the spraying height was 1.5 m and the spraying velocity 5 m s⁻¹, the droplet deposition in the lower layer was maximized, and the droplets exhibited the most uniform distribution (CV = 23%). The insecticidal efficacy was 92%–74% from 3 to 10 days after spraying insecticide. Both the insecticidal efficacy and the persistence period were greater than those achieved with a hand lance operated from a stretcher-mounted sprayer (at dose of 432 g a.i. ha⁻¹, spray volume rate of approximately 750 l ha⁻¹), especially on the 5th day, indicating that UAV had a low-volume and highly concentrated spray pattern to enhance the duration of efficacy. This work offers a basis for the optimized design, improved performance, and rational application of UAV.     

The effect of the air blast sprayer speed on the chemical distribution in vineyard

A study was conducted to determine the spray deposition patterns for air blast sprayers used to apply chemicals to the canopy of Semillon grapevine in vineyard. The application carried out in 12 bars and three sprayer speed (2.1-4.9-7.7 km h(-1)). The spray deposition was measured on the point in the different distances (1.5-3-6-9 m). Tartrazine were applied as tracer material. Maximum spray deposit was obtained 66.1 mg cm(-2) at sprayer speed of 2.1 km h(-1) and minimum deposit was obtained 37.1 mg cm(-2) at sprayer speed of 7.7 km h(-1). The results showed that the sprayer speeds had significant effect on spray deposit distribution and increasing of the sprayer speed increased drift.     

A practical scheme for estimating swath width using ULV sprays

Starting from a simplified model of the aerial dispersion of ULV sprays released from an aircraft perpendicular to the wind direction, a scheme is described for evaluating the total deposition distribution occurring during multiswath spraying. In conditions of overlapping deposition patterns, it is shown that the average concentration generally increases with the downwind distance and is characterized by a pattern of peaks and troughs dependent on the lane spacing. By choosing a suitable reference level on the deposition distribution and matching it to a threshold dose D_t (the minimum area coverage incident on the top of a crop) an optimum swath width can be defined on the basis of minimizing the operational time per unit area sprayed. Estimates of the swath width ω can be obtained by evaluating the expression ω = CQ/ψD_t where C = 0·5 is a derived coefficient, Q is the spray volume emitted per unit distance of flight, and ψ is an overdose coefficient, dependent on meteorological factors—which guarantees D_t to a selected level of probability. For small droplets (diameter 70 μm) the previous expression is fairly insensitive to wind speed, wind direction and atmospheric stability. On an area basis, an overdose (applied dose/threshold dose) is required to take account of both variability in the wind structure and variations in the deposition distribution. A series of worked examples provide insight into the choice of swath width and the associated flying height and demonstrate the practical application of the analysis.     

Lagrangian numerical simulations of canopy air flow effects on maize pollen dispersal

A three-dimensional Lagrangian random flight model was constructed for numerical simulations of maize pollen dispersion. The model simulates the paths of tracer particles which are interpreted as individual pollen grains, with particle motion determined by the mean flow and a stochastic turbulent velocity. The Lagrangian approach was chosen because it can be extended to complex flow regimes. The capacity of the model to simulate measured patterns of pollen deposition was tested by comparing simulations to measurements for a small maize canopy isolated within a large field of soybeans near Ames, Iowa, USA in August 2003. For this application, measurements from a single point meteorological observation were used to generate a surface layer wind profile over the maize canopy and surrounding soybean field. The method used to construct the wind field included development of internal boundary layers as the airflow passed from one canopy surface to another. The dispersion model produced spatial patterns of particle deposition that included the sharp near-source deposition gradient consistent with observations. The model tended to over-predict particle deposition near the source field and under-predict deposition at greater distances. Inclusion of the effect of the roughness difference between the maize canopy and the surrounding soybean canopy on the flow field was found to be essential for simulation accuracy. Agreement with observations improved considerably by including an approximation for vertical motions induced by changes in surface cover. These results indicate that the Lagrangian random flight model provides a realistic simulation of pollen dispersal from an isolated maize canopy. A more complete hydrodynamic model should be explored to better represent the influence of surface inhomogeneities on winds and turbulence.     

Distribution patterns of aerially applied ULV sprays by aircraft over and within the cotton canopy in the Sudan Gezira

A series of experimental ULV sprays by aircraft were conducted over four 35 ha cotton fields in the Sudan Gezira. The aim was to compare the pattern of deposit distribution over and within the cotton canopy when two ULV spray spectra designated for convenience as coarse (120 μm VMD) and fine (80 μm VMD) were released in the early morning (0600 h), mid-morning (0900 h), midday (1130 h) and mid-afternoon (1530 h). Results showed that early morning sprays produced a rather narrow useful swath from both coarse and fine sprays and high risk of drift from fine droplets. Both droplet spectra in the mid-morning spray, on the other hand, provided a good deposit pattern within the cotton canopy and had the least amount in the air at 100 m downwind. Furthermore, the fine spray gave a swath almost 50% wider than the coarse one. At noon the swaths were approximately intermediate to those of the early and mid-morning sprays. However, the variation of deposits at any one point was large and the amounts remaining airborne at 100m downwind were substantial. During mid-afternoon, wind over the Gezira was generally light and variable. As, in practice, the pilot flies invariably along the length of the field rather than across the wind direction, mid-afternoon sprays produced peaky deposits over a narrow swath. With regard to penetration of spray droplets into the canopy, the physical structure of the latter proved to be the determining factor. Turbulence generated by wind or the aircraft had no detectable effect.