Development and assessment of a novel servo-controlled spraying system for real time adjustment of the orientation angle of the nozzles of a boom sprayer

Background

Pesticide spray drift, which is the movement of pesticide by wind to any location other than the intended area, is hazardous to human, animal, food safety and environmental health. It is not possible to completely eliminate spray drift during spraying with field crop sprayers, but spray drift can be reduced by developing new technologies. The most common methods to reduce spray drift are carrying the droplets to the target with air-assisted spraying, electrostatic spraying, preferring air induction nozzles and boom shields. With these methods, it is not possible to make a change on the sprayer depending on the wind intensity during spraying. In this study, a novel servo-controlled spraying system was designed and developed to change the nozzle orientation angle in the reverse direction of the wind current to reduce the ground spray drift in real time and automatically in a wind tunnel. The displacement in the spray pattern (D_c) was used as a ground drift indicator for each nozzle to evaluate the spray drift.

Results

The developed system, operated by LabVIEW software, calculated different nozzle orientation angles depending on nozzle types, wind velocities and spraying pressures. Orientation angles calculated for different test conditions achieved in reduction were up to 49.01% for XR11002 nozzle, 32.82% for AIXR11002 nozzle and 32.31% for TTJ6011002 nozzle at 400 kPa spray pressure and 2.5 m s⁻¹ wind velocity.

Conclusion

The developed system, which has a self-decision mechanism, calculated the nozzle orientation angle instantaneously according to the wind velocity. It has been observed that the adjustable spraying nozzle system, sprayed with high precision towards the wind in the wind tunnel, and the developed system have advantages compared to conventional spraying systems. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Effect of spray application technique on spray deposition in greenhouse strawberries and tomatoes

BACKGROUND: Increasingly, Flemish greenhouse growers are using spray booms instead of spray guns to apply plant protection products. Although the advantages of spray booms are well known, growers still have many questions concerning nozzle choice and settings. Spray deposition using a vertical spray boom in tomatoes and strawberries was compared with reference spray equipment. Five different settings of nozzle type, size and pressure were tested with the spray boom. RESULTS: In general, the standard vertical spray boom performed better than the reference spray equipment in strawberries (spray gun) and in tomatoes (air‐assisted sprayer). Nozzle type and settings significantly affected spray deposition and crop penetration. Highest overall deposits in strawberries were achieved using air‐inclusion or extended‐range nozzles. In tomatoes, the extended‐range nozzles and the twin air‐inclusion nozzles performed best. Using smaller‐size extended‐range nozzles above the recommended pressure range resulted in lower deposits, especially inside the crop canopy. CONCLUSIONS: The use of a vertical spray boom is a promising technique for applying plant protection products in a safe and efficient way in tomatoes and strawberries, and nozzle choice and setting should be carefully considered. Copyright © 2009 Society of Chemical Industry     

Spray drift as influenced by meteorological and technical factors

BACKGROUND: The objective of this study was to investigate spray drift from a conventional field sprayer as influenced by meteorological and technical factors, and to provide spray operators with data on which to base sound judgements when applying pesticides. The study was conducted in grazing fields and cereal crops. RESULTS: Interpreting the results from 15 field trials under varying meteorological conditions using different boom heights and driving speeds indicates that, during normal spraying conditions, the most decisive factors influencing the total spray drift (TSD) will be boom height and wind speed, followed by air temperature, driving speed and vapour pressure deficit. One important finding was that TSD (within the encompassed range of meteorological conditions and a boom height of 0.4 m) could be expressed as a simple function of the fraction of droplets ≤ 100 µm. In cereal crops: TSD = 0.36 + 0.11× [fr. (d ≤ 100 µm)] and in grazing fields, TSD = 1.02 + 0.10× [fr. (d ≤ 100 µm)]. In most cases a fraction of the airborne drift passed over the 6 m sampling mast located 5 m downwind of the spray swath. CONCLUSIONS: Under specified conditions, the present results indicate a simple relation between the total spray drift and volume fractions of droplets ≤ 100 µm. Given the nozzle type, it was concluded that the most decisive factors determining TSD are wind speed and boom height. Evaluating the relative importance of the meteorological and technical factors contributes to increasing knowledge in this field of research. Copyright © 2011 Society of Chemical Industry     

United States Department of Agriculture-Agricultural Research Service research in application technology for pest management

A research summary is presented that emphasizes ARS achievements in application technology over the past 2-3 years. Research focused on the improvement of agricultural pesticide application is important from the standpoint of crop protection as well as environmental safety. Application technology research is being actively pursued within the ARS, with a primary focus on application system development, drift management, efficacy enhancement and remote sensing. Research on application systems has included sensor-controlled hooded sprayers, new approaches to direct chemical injection, and aerial electrostatic sprayers. For aerial application, great improvements in on-board flow controllers permit accurate field application of chemicals. Aircraft parameters such as boom position and spray release height are being altered to determine their effect on drift. Other drift management research has focused on testing of low-drift nozzles, evaluation of pulsed spray technologies and evaluation of drift control adjuvants. Research on the use of air curtain sprayers in orchards, air-assist sprayers for row crops and vegetables, and air deflectors on aircraft has documented improvements in application efficacy. Research has shown that the fate of applied chemicals is influenced by soil properties, and this has implications for herbicide efficacy and dissipation in the environment. Remote sensing systems are being used to target areas in the field where pests are present so that spray can be directed to only those areas. Soil and crop conditions influence propensity for weeds and insects to proliferate in any given field area. Research has indicated distinct field patterns favorable for weed growth and insect concentration, which can provide further assistance for targeted spraying.     

冠层推拨装置对喷杆喷雾机雾滴飘失与沉积特性的影响

喷杆喷雾机具有作业效率高、雾滴覆盖率高、沉积分布均匀、防治效果好等优点,是目前大田作物最主要的施药机具.但受作物冠层遮挡和侧风等气象条件的影响,导致喷杆喷雾机作业时雾滴难以穿透到植株中下部并伴随飘失.为改善喷杆喷雾机喷雾雾滴在作物冠层的穿透性并降低飘移量,本文优化设计了一种适用于大田作物的喷杆喷雾机冠层推拨装置.并分别...     

Restriction of Application Losses during Aerial Sprayings1

Results are reported on the prevention of losses of pesticide liquids due to droplet drift during aerial spraying. The effect of two basic factors was tested: a) change in drop size achieved either by use of different nozzles or by their modification or by regulation of the physical properties of the pesticide liquids; b) change of external conditions of drop fall achieved by the regulation of flight altitude, arrangement of nozzles on the aircraft, accuracy of operation of the spraying equipment The experiments proved that droplet size was most affected by use of TeeJet nozzles with Sabatka terminals, and to a lesser extent by the Lo-Drift agent Both factors limited the formation of the smallest drops, up to 100 μm especially. Accurate operation and maintenance of the spraying equipment (especially timely turning off at the end of lanes) has a great effect on limiting drift Optimum flight altitude (according to wind speed) is a compromise between the effort to limit drift and droplet evaporation and the achievement of required uniformity of deposition (CV). With the Z-37 aircraft, the optimum flight altitude in good weather conditions is about 4-5 m. Earlier experiments (to 1978) indicated good results with the addition of Ulvapron agent (21/ha) and Trition CS 7 (0.3%) mainly in warm (above 20°C) and dry (below 60 % R.H.) weather.     

农药有效利用率与喷雾技术优化

提高农药的有效利用率是植保工作者非常关心的问题。本文阐述了农药有效利用率的广义和狭义涵义,并分析了农药使用中存在的药剂浪费、有效利用率低的问题。根据喷雾技术中的“剂量传递”过程,分析了农药有效利用率的狭义涵义,在春季果园和作物苗期,常规喷雾法的农药有效利用率只有20%~30%;在夏秋季果园和作物中后期,随着作物叶面积系数（LAI）的增加,农药的有效利用率可达到50%~60%。论文分析了造成农药有效利用率低的原因,提出喷雾技术的优化措施：（1）大田喷雾时采用机动喷杆喷雾替代背负式手动常规喷雾,可以改善雾滴沉积分布的均匀性;（2）添加喷雾助剂可以提高药液在靶标表面的润湿性;（3）优化雾滴粒径,采用细雾滴替代粗雾滴可以提高雾滴的中靶率;（4）降低施药液量可以减少药液流失;（5）加装挡板可以减少雾滴飘失等。通过以上技术的优化,可以大幅度提高农药的有效利用率,达到减量增效的目的。     

Application technology,emission and safety in glasshouse spraying1

Two major trends can be distinguished in the application technology of plant protection products in glasshouses: unmanned application of very low volumes of chemical, e.g. by low-volume mister equipment, and the so-called high-volume application, traditionally by human labour, by means of hydraulic nozzles mounted on a spraying stick, a spraying mast or a spraying boom. Measurement equipment was used 10 characterize the application quality. spray evenness, leaf coverage and soil and roof contamination in Dutch glasshouses. The condition of the average spraying equipment used in daily practice proved to be bad. A mathematical model was also developed to predict the emission of products from the glasshouse during and after spraying. Calculations were made to investigate if active filtration of the air inside the glasshouse could prevent pollution of the outside atmosphere significantly. This could not be confirmed.     

Modern Technology for Aerial Application of Agrochemicals1

Most pesticides and fertilizers are applied by aerial techniques in the agricultural farms of Hungary. The importance of the work done by plane or helicopter is characterized by the following data: in regions having many planes more than 50% of the plant protection activity is carried out by aerial application. Another characteristic feature of Hungarian agricultural aviation is the fact that almost 35% of the total spraying involves the application of herbicides, defoliants and desiccants. Large-scale use of formulations dangerous for the environment has made it necessary to take some important measures, such as directed spraying, regulation of drop sizes etc. With the development of these methods and the transformation of spraying equipment it became possible to carry out spraying under optimal biological conditions. Nowadays aircraft are used in at least one production process for crops such as cereals, rice, maize, sunflower, sugar beet, potato and vegetables and vines (chemical weed control, spraying for the control of fungi or insects, desiccation). Finally it should be mentioned that all equipment is mounted with the membrane-lock nozzles developed by the Aviation Service of the Ministry of Agriculture and Food to meet the requirements of modern technology. A very promising part of this activity is the development of rotating nozzles for helicopters (electrically driven) and for planes (wind driven).     

植保施药机械喷雾雾滴飘移研究进展

中国农药产品80％以上通过喷雾方式施用,药液从喷头到靶标作物过程中产生的随风飘移和蒸发飘移是农药造成人畜健康风险、生态环境破坏的重要因素之一.随着航空施药技术的发展,解决或减少喷雾雾滴飘移的问题成为施药技术研究的重点和热点.基于此,本文分别从喷雾雾滴(尺寸分布、黏度、表面张力、蒸气压、挥发性、密度等)、喷雾模式(喷头类...     

Effects of nozzle type and spray angle on spray deposition in ivy pot plants

BACKGROUND: Fewer plant protection products are now authorised for use in ornamental growings. Frequent spraying with the same product or a suboptimal technique can lead to resistance in pests and diseases. Better application techniques could improve the sustainable use of the plant protection products still available. Spray boom systems—instead of the still predominantly used spray guns—might improve crop protection management in greenhouses considerably. The effect of nozzle type, spray pressure and spray angle on spray deposition and coverage in ivy pot plants was studied, with a focus on crop penetration and spraying the bottom side of the leaves in this dense crop. RESULTS: The experiments showed a significant and important effect of collector position on deposition and coverage in the plant. Although spray deposition and coverage on the bottom side of the leaves are generally low, they could be improved 3.0–4.9‐fold using the appropriate application technique. CONCLUSIONS: When using a spray boom in a dense crop, the nozzle choice, spray pressure and spray angle should be well considered. The hollow‐cone, the air‐inclusion flat‐fan and the standard flat‐fan nozzle with an inclined spray angle performed best because of the effect of swirling droplets, droplets with a high momentum and droplet direction respectively. Copyright © 2010 Society of Chemical Industry     

航空喷雾植保技术的发展与探讨

航空喷雾在我国农作物病、虫、草害防治中得到了广泛应用。为促进航空喷雾技术的发展,本文对国内外航空喷雾的发展历程、作业技术以及作业设备进行了简要概述和总结,并结合我国航空植保技术的现状,在航空喷雾作业机型、应用技术以及作业装置等方面进行了探讨。通过综述分析,作者认为在我国航空喷雾技术领域,应重视和逐步发展直升机、无人机的应用,加强作业设备控制系统的研发和喷洒部件的系列化与配套,深入进行航空喷雾飘移控制技术研究,以提高我国航空植保应用水平。     

Biological responses to glyphosate drift from aerial application in non‐glyphosate‐resistant corn

BACKGROUND: Glyphosate drift from aerial application onto susceptible crops is inevitable, yet the biological responses to glyphosate drift in crops are not well characterized. The objectives of this research were to determine the effects of glyphosate drift from a single aerial application (18.3 m swath, 866 g AE ha^?1) on corn injury, chlorophyll content, shikimate level, plant height and shoot dry weight in non‐glyphosate‐resistant (non‐GR) corn. RESULTS: One week after application (WAA), corn was killed at 3 m from the edge of the spray swath, with injury decreasing to 18% at 35.4 m downwind. Chlorophyll content decreased from 78% at 6 m to 22% at 15.8 m, and it was unaffected beyond 25.6 m at 1 WAA. Shikimate accumulation in corn decreased from 349% at 0 m to 93% at 15.8 m, and shikimate levels were unaffected beyond 25.6 m downwind. Plant height and shoot dry weight decreased gradually with increasing distance. At a distance of 35.4 m, corn height was reduced by 14% and shoot dry weight by 10% at 3 WAA. CONCLUSIONS: Corn injury and other biological responses point to the same conclusion, that is, injury from glyphosate aerial drift is highest at the edge of the spray swath and decreases gradually with distance. The LD₅₀ (the lethal distance that drift must travel to cause a 50% reduction in biological response) ranged from 12 to 26 m among the biological parameters when wind speed was 11.2 km h^?1 and using a complement of CP‐09 spray nozzles on spray aircraft. Published 2010 by John Wiley & Sons, Ltd.     

Challenges and opportunities of unmanned aerial vehicles as a new tool for crop pest control

The application of pesticides is not simply delivering chemicals to the target area. It also involves considering the negative aspects and developing strategies to deal with them during the application process, to ensure the maximization of pesticides use efficiency and the maintenance of the ecosystem. Unmanned aerial vehicle (UAV) sprayers demonstrate unique advantages compared to traditional ground sprayers, particularly in terms of maneuverability and labor intensity reduction, showed great potential for chemical application in pest control. It is undeniable that there exist challenges in the practice of UAV spraying, such as higher potential risks of pesticide drift or pathogen transmission, uncertainty canopy deposition for different crops, and unexpected leaf breakage induced by downwash flow. Maximizing the utilization of downwash flow while avoiding lateral air movement outside the intended target crop area is a major issue for chemical application with UAV sprayers, particularly in light of the increasingly apparent consensus on the need for enhanced environmental protection during the chemical application process. It must be considered that the operation strategy in different scenarios and for different crop targets is not the same, unique requirements should be given on nozzle atomization, flight parameters, adjuvants and aircraft types in specific working situations. In future, the implementation of spray drift prediction, technical procedures development, and other solutions aimed at reducing pesticide drift and improving deposition quality, is expected to promote the adoption of UAV sprayers by more farmers. © 2023 Society of Chemical Industry.     

Buffer zone and windbreak effects on spray drift deposition in a simulated wetland

The amount of agricultural spray that drifts into a wetland from an adjacent crop field is influenced by vegetation along the field boundary or any intentional setback distance (buffer zone) between the sprayer and the edge of the arable field. In this study, spray tracer drift deposits were measured in a simulated wetland area under different conditions of wind speed and buffer zone width. The effect of an artificial windbreak at the upwind edge of the simulated wetland was also evaluated. A level of tolerance of 0.1% of the in-swath spray deposition was established as a no-effect level for the response of aquatic plants to common herbicides. Our results indicate that a vegetated 10-m field margin (eg a fencerow) alone provides adequate protection from herbicide drift into a wetland area under wind conditions normally considered acceptable for spraying. For high winds (> 4m s(-1)) when field spraying would not normally be advised, adequate protection was afforded by the same 10-m margin plus a dense windbreak (25% porosity) or by the margin plus a 20-m buffer zone.     

风洞环境下喷头及助剂对植保无人飞机喷雾飘移性的影响

为探究和减少植保无人飞机喷雾施药过程中的雾滴飘移,采用由单个旋翼与喷头组成的喷雾单元,在可控风洞环境条件下进行了模拟飞行喷雾试验,控制风洞条件为风速5 m/s、喷雾压力0.3 MPa及旋翼转速2300 r/min不变,对比研究了11种喷头、4种代表性助剂以及不同温度/相对湿度条件对雾滴飘移的影响,采用飘移潜在指数(DIX)及相对减飘率(DPRP)两项指标进行对比评估。结果表明:在温度/相对湿度为20℃/RH 80%条件下,不同类型喷头喷雾药液在空中垂直面和水平距离上的飘移沉积量分布均呈现显著的规律性变化趋势,与对照喷头F110-03相比,喷头飘移潜在性从大到小依次为:TR80-0067>ST110-0067>XR110-01>ST110-015>TR80-01>ST110-02>XR110-03>对照F110-03>IDK系列,其中IDK120-01与IDK120-015喷头的减飘移效果相近并为最好;在30℃/RH 40%条件下,采用XR110-01喷头,分别添加助剂0.5%Silwet DRS-60、1.0%"迈飞"(MF)和1.0%Y-20079后,与不添加助剂的对照相比,平均减飘率分别为43.3%、15.6%和5.2%,表明不同助剂对飘移的影响不同,需考虑助剂类型及其减飘效果合理选用;在20℃/RH 40%、20℃/RH 80%、30℃/RH 40%和30℃/RH 60%条件下,XR110-01喷头与添加1.0%MF助剂组合有利于空中飘移的减少,尤其是高温/低湿条件下,添加助剂的减飘移效果较好。该研究结果可为植保无人飞机的喷头选择、喷雾助剂筛选和实际应用提供参考和指导,并为进一步研究喷头及助剂的减飘技术提供数据基础。     

Patch spraying: future role of electronics in limiting pesticide use

Developments relating to the control of application equipment can deliver improvements in pesticide use by better matching applications to target requirements. This may have components relating to the spatial distribution of a weed, pest or disease or methods by which the target, particularly a crop canopy, can be described with respect to a given application. Changes in application can relate to the dose and/or volume applied, but may also concern the way in which a treatment is delivered in terms of parameters such as spray trajectory angle and droplet size distribution. For many weed species there is evidence of patchy distributions in field situations. Studies have shown that savings of typically up to 40% in herbicide use can be achieved by adopting patch spraying approaches in such situations. Weed patch detection is key to the performance of such patch spraying systems. In widely spaced rowcrops such as vegetables, there is considerable scope for developing fully automated detection systems based on image analysis, and for the development of accurate guidance systems that apply pesticides only to the crop row. In crops with a relatively high plant density, weed detection in the medium/short term is likely to be based on manual discrimination. The costs of labour for manual weed patch mapping have been estimated at less than 1.50 ha(-1) pounds sterling. Potential savings in pesticide use can also be made if applications are matched to crop canopy structure. This is most important in bush and tree crops where savings of up to 75% in pesticide use could be achieved. In crops such as cereals, studies have shown that savings in fungicide use may be possible, particularly at earlier stages of growth by adjusting spray delivery to measured canopy characteristics. Key components of the performance of application systems concern the ability to deliver over a dose rate range of more than 3:1 while maintaining control of variables such as delivery trajectory angle and spray quality. Traceability and the effective monitoring of applications is likely to be a major driver influencing the uptake of more sophisticated control systems. Methods of labelling pesticides with systems that can be read by the application unit will be an important step in the development of recording and data handling systems that will operate safely with the minimum of operator input and enable the environmental advantages of targeted pesticide application to be monitored.     

The effects of boom height, working pressure and wind speed on spray drift

Investigations of the effects of varying the boom height, working pressure, and wind speed on spray drift from a field sprayer are reported. By increasing the boom height from 40 to 80 cm drift increased from 1% to 3–2%; by increasing the pressure from 2–5 bar to 10 bar drift increased from 1–4% to 2–9%, and by increasing the wind velocity from approximately 1–5 m/s to approximately 4–0 m/s drift increased from 1–4% to 2–9%. A significant negative correlation was found between drift and the logarithm of the distance from the nozzle. A significant positive correlation was found between drift damage on barley plants and the logarithm of the spray-liquid deposit. Under ideal conditions, and with correctly adjusted spray equipment, total spray drift was 14% of applied spray. Under unfavourable conditions, and with wrong adjustments of the sprayer (boom height and pressure) drift was 37% of the applied spray. It is concluded that field spraying should not be carried out in wind speeds of more than 3 m/s. The boom should be approximately 40 cm high, and the working pressure should not exceed 2–5 bar for herbicide spraying. Effet de la hauteur de la rampe, de la pression de travail et de ia Vitesse du vent sur les entraînements de pulvérisqtion par embruns Les auteurs rapportent les résultats de recherches sur les effets de la variation de hauteur de ta rampe, de la pression de travail et de la vitesse du vent sur I'entraînement des embruns provenant d'un pulvérisateur à grand travail. L'élévation de ia rampe de 40 à 80 cm a accru I'entraînement de 1 à 3,2%; I'augmentation de la pression, de 2.5 à 10 bars a accru I'entraînement de 1,4 h 2,9% et I'augmentation de la Vitesse du vent de 1,5 à 4,0 màtres/sec a accru I'entraînement de 1,4 à 2,9%. Une corrélation négative significative a été trouvée entre Tentraînement et le logarithme de la distance à partir de la buse. Une corrélation positive significative a été trouvée entre I'entraînement et le logarithme du dépét de la bouillie pulvérisée. Dans les conditions optimales et avec un pulvérisateur correctement réglé, I'entraînement total a été de 1,4% du traitement appliqué. Dans des conditions défavorables et avec des régiages défectueux du pulvérisateur. (hauteur de la rampe et pression) I'entraînement a atteint 37%. En conclusion, les traitements au champ par pulvérisation ne doivent pas être effectuées si la vitesse du vent dépasse 3 m/sec. La rampe doit être à 40 cm du sol environ et la pression de travail ne doit pas excéder 2,5 bars pour une pulvérisation effectuée avec un herbicide. Der EirtJJiiss ion Spritzbalkcnhohe, Betriebsdriick und Wind-geschwindigkeit aufdie Abtrift. Eswird über den Einfluss unterschiedlicher Spritzbalkenhöhen, Betriebsdruck und Windgeschwindlgkeit aufdie Abtrift beien einem Feldspritzgerät berichtet. Bei Erhöhung des Spritzbalkens von 40 auf 80 cm stieg die Abtrift von I auf 3,2%; eine Steigerungdes Druckes von 2,5 auf 10 bar erhöhte die Abtrift von 1,4 auf 2,9% und durch eine Erhöhung der Windgeschwindigkeit von etwa 1,5 m/s auf etwa 4 m/s, steigerte sich die Abtrift von 1,4 auf 2,9%. Zwischen der Abtrift und dem Logarithmus des Abstandes von der Düse, wurde eine gesichertc negative Korrelation gefunden. Eine gesicherte positive Korrelation ergab sich zwiscben Abtrift Beschädigung von Gerste und dem Log-arithmus des Spritzbelages. Bei idealen Dedingungen und richtig eingestelltem Spritzgerät, betrug die gesamie Abtrift 1,4% der ausgebrachten Bruhe. Unter ungüstigen Bedingungen und fiihcher Einstell-ung (Spritzbalkenhöhe und Druck), betrug die Abtrift 37%. Aus den Ergcbnissen wird geschlossen. dass man bei Windgeschwindigkeiten von mehr als 3 m/s nicht spritzen sollte. Der Spritzbalken sollte etwa 40 cm hoch sein und der Betriebsdruck sollte bei Herbizidspritzungen 2,5 bar nicht überschreiten.     

Droplet Formation and Deposition1

At the EPPO Conference in Belgrade on 1970 the author reported on work showing that small, uniform, and non-volatile droplets appeared to offer the prospect for greatly reduced dosages of pesticides by both providing a more effective deposit and by controlling drift. Three recent studies provide further evidence for this hypothesis, which questions the very principles on which our present spraying practices are based. However, the deposition of droplets by the external forces of wind and gravity imposes lower limits on the droplet sizes capable of being used. These are 30 μm for insecticides and fungicides (except in the case of flying insects) and 150 μm for herbicides, since the droplets require sufficient energy to impact themselves on the target. Electrostatic charging of droplets promises to free us from these size constraints by providing the droplet with a depositional force of its own, allowing it to impact on any surface. Electrostatics, however, is solely a force of deposition and thus must be balanced with the forces required for spray dispersion so that the droplets can penetrate the crop canopy and/or be transported to the target     

不同助剂、喷头及喷雾压力对自走式喷杆喷雾机稻田喷雾效果的影响

以亿丰丸山3WP-500CN型号自走式喷杆喷雾机为研究对象,以诱惑红85作为指示剂,测定了6种喷雾助剂 (红太阳、倍力、迈丝、融透、印楝油和哈速腾)、3种喷头 (TEEJET-VP80015、ASJ-VP110015和LICHENG-VP11003) 以及3种喷雾压力 (0.2、0.4 和0.6 MPa) 对农药沉积利用率、药液雾化性能 (D₅₀值雾滴密度等)、雾滴分布均匀性等喷雾参数的影响,以及240 g/L噻呋酰胺悬浮剂对水稻纹枯病防治效果及水稻产量的影响。结果表明:采用TEEJET-VP80015喷头,在0.4 MPa喷雾压力条件下,助剂哈速腾雾滴分布均匀性显著高于其他助剂,变异系数为0.11,同时对雾滴估计沉积量 (45.74 μL/cm2) 与分布跨度 (1.29) 的影响显著高于其他助剂;助剂迈丝对雾滴密度 (103.78个/cm2) 和农药沉积利用率 (83.88%) 的影响均显著高于其他助剂。采用TEEJET-VP80015喷头,在未添加助剂条件下,不同喷雾压力对雾滴分布跨度、雾滴附着率和农药沉积利用率影响差异显著,其中在0.6 MPa压力下,分布跨度为1.18,雾滴附着率为33.32%,农药沉积利用率为78.19%。在未添加助剂、0.4 MPa喷雾压力条件下,喷头LICHENG-VP11003对雾滴分布均匀性的影响显著高于另外两种喷头,变异系数为0.12,同时对雾滴覆盖率 (69.37%)、雾滴估计沉积量 (42.77 μL/cm2) 和农药沉积利用率 (75.79%) 的影响也显著高于另外两种喷头。各测定条件下,240 g/L噻呋酰胺悬浮剂对水稻纹枯病的防治效果与雾化性能和雾化参数结果一致,其中添加助剂迈丝后防治效果达到89.27%,显著高于添加其他助剂,增大喷雾压力到0.6 MPa,防治效果达到88.67%,显著高于其他压力条件;采用TEEJET-VP80015喷头,在0.4 MPa喷雾压力下,水稻产量为8301 kg/hm2,显著高于人工喷雾。因此,助剂与喷头类型均对自走式喷杆喷雾机施药时的农药沉积利用率、雾滴分布均匀性以及雾滴参数和雾化效果有显著的影响,在适当的喷雾压力下添加助剂可提高农药的防治效果。