Application Volume Rate Research Articles

Assessing the efficiency of UAV for pesticide application in disease management of peanut crop.

Effective utilization of plant protection UAVs in peanut cultivation management necessitates a comprehensive grasp of how application volume rates and pesticides influence peanut leaf spot and rust control. This study aimed to compare the effects of application volume rates and pesticides on droplet deposition, disease, leaf retention rate and peanut yield. A T20 plant protection unmanned aerial vehicle (UAV) sprayer was used to apply four various pesticide doses. In comparison, a knapsack sprayer was used to spray with an application volume rate of 450 L ha-1. The results showed a significant difference in droplet deposition between the plant protection UAVs and the electric knapsack sprayer. In the pesticide treatment with an application volume rate of 15.0 L ha-1, there was no significant difference in the deposition on the peanut canopy of each pesticide treatment, but there was a significant difference in the deposition on the ground in the treatment with adding vegetable oil adjuvant. The treatment with added vegetable oil additives showed the worst performance. The treatment with an application volume rate of 22.5 L ha-1 showed the best performance, with the leaf spot control effect being only 0.3% lower than that of the electric knapsack sprayer. Plant protection UAV spraying is feasible to control peanut diseases. Considering the operational effectiveness of the plant protection UAV and application volume rate, it is recommended to use an application volume rate of 22.5 L ha-1 without adding vegetable oil adjuvants for field operations. © 2024 Society of Chemical Industry.

Evaluating the use of unmanned aerial vehicles for spray applications in mountain Nanguo pear orchards.

Nanguo pear is a distinctive pear variety in northeast China, grown mainly in mountainous areas. Due to terrain limitations, ground-based pesticide application equipment is difficult to use. This limitation could be overcome by using unmanned aerial vehicles (UAVs) for pesticide application in Nanguo pear orchards. This study evaluated the spraying performance of two UAVs in the Nanguo pear orchards and compared them with a manually used backpack electric sprayer (BES). The study also analyzed the effect of canopy size on droplet deposition and ground loss, and evaluated two sampling methods, leaf sampling and telescopic rod sampling. Compared to BESs, droplet deposition is lower for UAVs, but the actual pesticide active ingredient deposition is not necessarily lower given the solution concentration. The droplet deposition varies among different UAVs due to structural differences. Under the same UAV operating parameters, droplet deposition on trees with smaller canopy sizes is typically greater than that on trees with larger canopy sizes, and the ground loss was also more severe. Although telescopic rod sampling is a quick and convenient method, it can only reflect the trend of droplet deposition, and the data error is greater compared with leaf sampling. UAVs can achieve better droplet deposition in mountainous Nanguo pear orchards and does almost no harm to the operators compared with the BES. However, canopy size needs to be considered to adjust the application volume rate. Telescopic rods can be used for qualitative analyses, but are not recommended for quantitative analyses. © 2024 Society of Chemical Industry.

Application technology for bioherbicides: challenges and opportunities with dry inoculum and liquid spray formulations.

Bioherbicides offer many potential benefits as part of an integrated weed management system or a totally biological or organic cropping system. A key factor for success is the selection of appropriate formulation and delivery systems for each target weed and cropping/climatic region. For dry inoculum products, we discuss direct implantation as an example for successful control of woody weeds, with benefits in control extending beyond the treated weeds to surrounding weeds. These applications do not require water and will become less labor-intensive with future robotic application platforms. Indeed, all bioherbicide applications are likely to improve and become more cost-effective with the advance of new application platforms with sensors and targeted control at lower application volume rates. Unmanned aerial vehicles, as new application platforms, are one of several such potential progressive application systems for liquid formulations, and we discuss product design to maintain optimum conditioning of the active ingredient(s) and storage stability. The delivery system must not adversely affect the products and the application volume rate must be appropriate for coverage on the target. Where applied with other products, compatibility must be ensured and appropriate mixing orders observed to assure performance and avoid precipitation or settling. Droplet size is important for allowing the active materials to be included in the spray, which may require droplets with diameter >150 μm for some larger particle biologically active agents. However, droplet size should not be too large to achieve target coverage. In some cases, that may be plant stems rather than leaves, or narrow grass weeds which tend to have highest spray collection efficiency for small droplets. Narrow droplet size spectrum nozzles may help optimize droplet size. We propose spray calculators to help optimize performance for coverage, retention and avoidance of drift losses, bounce, shatter and runoff. These include regulatory-supported, validated models. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of Operational Parameters of Unmanned Aerial Vehicle (UAV) on Droplet Deposition in Trellised Pear Orchard

Background: Unmanned Aerial Vehicles (UAVs) are increasingly being used commercially for crop protection in East Asia as a new type of equipment for pesticide applications, which is receiving more and more attention worldwide. A new model of pear cultivation called the ‘Double Primary Branches Along the Row Flat Type’ standard trellised pear orchards (FT orchard) is widely used in China, Japan, Korea, and other Asian countries because it saves manpower and is suitable for mechanization compared to traditional spindle and open-center cultivation. The disease and pest efficacy of the flat-type trellised canopy structure of this cultivation is a great challenge. Therefore, a UAV spraying trial was conducted in an FT orchard, and a four-factor (SV: Spray application volume rate, FS: Flight speed, FH: Flight height, FD: Flight direction) and 3-level orthogonal test were designed. Results: These data were used to analyze the effect, including spray coverage, deposit density, coefficient of variation, and penetration coefficient on the canopy, to determine the optimal operating parameters of the UAV for pest efficacy in FT orchards. The analysis of extremes of variance showed that factor FD had a significant effect on both spray coverage and deposition density. Followed by factor FS, which had a greater effect on spray coverage (p < 0.05), and factor SV, FH, which had a greater effect on deposition density (p < 0.05). The effects of different factors on spray coverage and deposit density were FD > FS > FH > SV, FD > FH > SV > FS, in that order. The SV3-FS1-FH1-FD3, which flight along the row with an application rate of 90 L/ha, a flight speed of 1.5 m/s, and a flight height of 4.5 m, was the optimal combination, which produced the highest deposit density and spray coverage. It was determined through univariate analysis of all experimental groups, using droplet density of 25/cm2 and spray coverage of 1%, and uniformity of 40% as the measurement index, that T4 and T8 performed the best and could meet the control requirements in different horizontal and vertical directions of the pear canopy. The parameters were as follows: flight along the tree rows, application rate not less than 75 L/ha, flight speed no more than 2 m/s, and flight height not higher than 5 m. Conclusion: This article provides ample data to promote innovation in the use of UAVs for crop protection programs in pergola/vertical trellis system orchards such as FT orchards. At the same time, this project provided a comprehensive analysis of canopy deposition methods and associated recommendations for UAV development and applications.

Pesticide dose adjustment in fruit and grapevine orchards by DOSA3D: Fundamentals of the system and on-farm validation

Agricultural productivity cannot be sustained without the application of plant protection measures. Within the framework of integrated pest management (IPM), the use of chemical pesticides should be limited to the last option among the available practices. Even though their use remains common, it carries associated environmental and human health risks. One of the most accepted practices within IPM is the reduction of spraying events and/or pesticide applied doses. DOSA3D is a decision support system that allows the dose to be adjusted to the specific treatment scenario. For this, DOSA3D calculates the optimal application volume rate by estimating the leaf area index and takes into account the overall spraying efficiency and the pest or disease to be controlled. The system adopts specific minimum volume rates for fruit trees and vineyards without compromising the crop health status. To establish the adjusted dose, the labeled or the adviser prescription concentration is kept. Resulting adjusted doses provided by DOSA3D achieved pesticide savings up to 53% in fruit trees and 60% in vineyards. DOSA3D has been validated against the main diseases and pests of fruit trees and vineyards: brown spot and psylla in pear orchards; alternaria blotch disease, apple scab, codling moth, oriental moth and red spider mite in apple orchards; powdery mildew, brown rot, aphids, thrips and mites in peach orchards; and, powdery mildew, yellow spider mite and leafhoppers in grapevine orchards. In addition, a methodology called Green Way is presented to provide consistent and crop safety pesticide doses when these are labeled as concentration or ground area doses.

Spray deposition and distribution on the targets and losses to the ground as affected by application volume rate, airflow rate and target position

Greenhouse crop production in China has in the recent years expanded widely. To minimize compromised pesticide use and adverse environmental impact in these structures, it is essential to optimize the working parameters and settings of sprayers. Experiments using an air assisted greenhouse sprayer and artificial plants with attached fruits were conducted to investigate the effects of volume rate, target location, and airflow rate on spray deposition and distribution uniformity on leaves, fruits and losses to the ground. Three spray volume rates (530, 368 and 220 l ha−1) and three nozzle's outlet volumetric airflow rates (374.4, 289.4 and 234.7 m3 h−1) were evaluated. Ground speeds were set at 0.36 and 0.31 m s−1 for volume rate and airflow rate trials, respectively. Artificial targets (filter-paper collectors) were attached on either sides of leaves, fruits and the ground to collect deposits of a food colourant used as a tracer (Spray solution). Deposition was quantified through UV-VIS spectroscopy at a wavelength of 508 nm. Results indicated that volume rate significantly influenced deposition and distribution uniformity. Reducing the volume rate reduced deposition but improved distribution homogeneity. Quantified absolute deposits on upper leaf surfaces declined by 27.4% (MV) and 43.3% (LV). Normalized deposition displayed under-leaf to upper-leaf deposition ratios of between 16.1% (HV) to 20.0% (LV). Ground deposits were reduced by roughly 37.3% (MV) and 54.7% (LV). Similar to volume rate, airflow rate influenced spray deposition on leaves but followed an opposite trend. Reducing airflow rate improved deposition although the effect attained a threshold at medium airflow rate beyond which further reduction the deposition decreased though the reduction was not statistically significant (P = 0.069). Airflow rate did not significantly affect ground deposits (P = 0.315) it reduced the quantity of spray lost by 7% (MF) and 8.4% (HF).

Efficacy of pre and postemergence herbicides on weed suppression in established turfgrass with a conventional and an ultra-low volume sprayer

Previous research has shown the effectiveness of an ULV (Ultra-Low Volume) sprayer compared to a conventional sprayer for weed control in row crop applications. This sprayer produced comparable disease control and foliar nutrient applications to a conventional sprayer in turfgrass, but has not previously been evaluated for weed control in established turf. Four weed control field studies were conducted in the spring and summer of 2012 and 2013 at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA to compare the weed control efficacy between a novel ULV sprayer and a conventional sprayer. The studies compared the two sprayers for the control of: ground ivy and dandelion in established turf in a summer application; preemergence control of large crabgrass in established turf in a late spring application and ground ivy control in established turf in a late spring application. No differences were observed in weed control between sprayer types in the four studies over both years of the study despite a thirty fold decrease in application volume rate across different herbicide modes-of-action in all of the studies. The Kamterter ULV sprayer system may be a useful and effective management option for control of the weeds in turfgrass.

Determining the drift potential of Venturi nozzles compared with standard nozzles across three insecticide spray solutions in a wind tunnel.

Previous research has sought to adopt the use of drift-reducing technologies (DRTs) for use in field trials to control diamondback moth (DBM) Plutella xylostella (L.) (Lepidoptera: Plutellidae) in canola (Brassica napus L.). Previous studies observed no difference in canopy penetration from fine to coarse sprays, but the coverage was higher for fine sprays. DBM has a strong propensity to avoid sprayed plant material, putting further pressure on selecting technologies that maximise coverage, but often this is at the expense of a greater drift potential. This study aims to examine the addition of a DRT oil that is labelled for control of DBM as well and its effect on the drift potential of the spray solution. The objectives of the study are to quantify the droplet size spectrum and spray drift potential of each nozzle type to select technologies that reduce spray drift, to examine the effect of the insecticide tank mix at both (50 and 100 L ha(-1) ) application rates on droplet size and spray drift potential across tested nozzle type and to compare the droplet size results of each nozzle by tank mix against the drift potential of each nozzle. The nozzle type affected the drift potential the most, but the spray solution also affected drift potential. The fine spray quality (TCP) resulted in the greatest drift potential (7.2%), whereas the coarse spray quality (AIXR) resulted in the lowest (1.3%), across all spray solutions. The spray solutions mixed at the 100 L ha(-1) application volume rate resulted in a higher drift potential than the same products mixed at the 50 L ha(-1) mix rate. The addition of the paraffinic DRT oil was significant in reducing the drift potential of Bacillus thuringiensis var. kurstkai (Bt)-only treatments across all tested nozzle types. The reduction in drift potential from the fine spray quality to the coarse spray quality was up to 85%. The addition of a DRT oil is an effective way to reduce the spray solution drift potential across all nozzle types and tank mixes evaluated in this study. The greatest reduction in drift potential can be achieved by changing nozzle type, which can reduce the losses of the spray to the surrounding environment. Venturi nozzles greatly reduce the drift potential compared with standard nozzles by as much as 85% across all three insecticide spray solutions. Results suggest that a significant reduction in drift potential can be achieved by changing the nozzle type, and can be achieved without a loss in control of DBM. © 2016 Society of Chemical Industry.

Assessing the deposition and canopy penetration of nozzles with different spray qualities in an oat (Avena sativa L.) canopy

Consistent spray coverage that is evenly distributed throughout the canopy is necessary to control pest populations that can negatively affect yield. As applicators are switching to Coarser spray quality nozzles to reduce risk and liability of pesticide spray drift, concerns about efficacy loss are growing. Previous research has indicated that small droplets are the most effective at penetrating through crop canopies, but newer nozzle technologies have improved the effectiveness of larger droplet or Coarser sprays. Research was conducted to assess the canopy penetration of nozzles that produce Coarse, Very-Coarse and Extremely-Coarse spray qualities compared to nozzles that produce Fine and Medium spray qualities. Kromekote collectors were positioned in four configurations in an oat (Avena sativa L.) var. ‘Yarran’ (AusWest Seeds, Forbes, NSW, Australia) crop to quantify the coverage and droplet number densities (droplets cm−2) across three application carrier volume rates: 50, 75 and 100 L ha−1. Applications were made in the field in 30 cm tall, tillering oats, with collectors arranged in a randomised complete block design with three replications. The entire study was repeated on the following day. Results showed that droplet number densities were inversely related to the droplet size produced by the nozzles, yet coverage was increased more by application volume rate than droplet size. Thus, both spray drift reduction and improved canopy penetration can be achieved with proper nozzle selection and operation parameters for the control of agronomic pests.

Electronic characterization of the phenological stages of grapevine using a LIDAR sensor

Canopy characteristics and their variation at all growth stages, together with the spatial distribution of plants in the field need to be considered in determining the application volume rate in fruit crops. Spray volume calculation in a vineyard needs to take into account concepts such as tree row volume (TRV), leaf wall area (LWA) and leaf area index (LAI). The objective of this work was to develop one protocol to characterize the canopy geometry of grapevine to determine BBCH stages using data sets measured manually and with LIDAR scanning. With this aim, a package called PROcess TO LIdar Data v.0.1 (PROTOLIDAR) was created in R environment to process the LIDAR scan information. Results showed a significant correlation between LIDAR impacts and LAI at each growth stage. The relationship between the estimated values of TRV or LWA, and the growth stage of the vine was statistically significant (R2=0.99 and R2=0.95, respectively). Finally, the geometry characterizations of the plants were represented in 2 or 3D maps in GRASS-GIS.

SPRAY PENETRATION INTO THE CITRUS TREE CANOPY FROM TWO AIR–CARRIER SPRAYERS

Field experiments were conducted to investigate the effect of sprayer type, application volume rate, and airflowrate on spray deposition along depth of the citrus canopy. The trees were sprayed from one side using a tower sprayer withcrossflow fans and rotary atomizers (Curtec) at three spray volume rates and a tower sprayer with an axialflow fan andhydraulic nozzles (Titan) at two spray volume rates and two airflow rates. Spray deposition was determined with fluorometryusing cotton ribbons as targets within the entire canopy depth at two heights.<br><br>For both sprayers, deposition decreased with canopy depth, and spray penetration was improved as the volume rateincreased. The effect of volume rate became significant after about 1 m and 2 m depths for the Curtec and Titan sprayers,respectively. At the highvolume rate, mean depositions of the two sprayers were not significantly different. In general,operating the Titan sprayer at 1600 rpm (lower airflow) gave mean deposition comparable to that at 2225 (rated) rpm (higherairflow). The effect of airflow on spray penetration was significant beyond about 2 m depth.

Effect of the Volume Rate of Application on the Glasshouse Performance of Crop Protection Agent/Adjuvant Combinations

Effect of the Volume Rate of Application on the Glasshouse Performance of Crop Protection Agent/Adjuvant Combinations

Effect of the Volume Rate of Application on the Glasshouse Performance of Crop Protection Agent/Adjuvant Combinations

The effects of volume rate of application on the glasshouse performance of three recently developed crop protection agent/adjuvant combinations are discussed. High volume rates of application on easy-to-wet foliage, such as potato (Solanum tuberosum, L.) caused reduction of the adjuvant-enhanced performance of dimethomorph seen at low volume rates. These reductions were largely attributable to relatively lower spray retention with spray drop coalescence and run-off being observed, particularly at the higher adjuvant rates. On difficult-to-wet foliage (wheat, Triticum aestivum, L. ; oat, Avena sativa, L.) two different effects were seen. With a metconazole formulation/'Dobanol' 91-6 combination on wheat, no systematic changes in performance were observed with change in volume rate. With a flamprop-M-isopropyl formulation/'Dobanol' 25-7 combination, statistically significant increases in performance were seen with increasing volume rate. In both cases the observations can be explained as the result of a combination of interacting factors involving spray pattern, spray deposition and, by inference, foliar uptake of the crop protection agent, the proportions of which differed between the two cases. It is suggested that the effect of volume rate of application on performance of adjuvant-containing formulations is investigated on easy-to-wet foliage to determine the upper limits and on difficult-to-wet foliage to determine any variation in performance that may occur. Such information will guide the design of field trials and may aid interpretation of field results.

Foliar residues of aminocarb at tree canopy and ground levels in an experimental spray operation in conifer forests

AbstractFoliar residues of aminocarb were measured at tree canopy and ground levels in conifer forests in New Brunswick, Canada, following aerial application of three spray mixtures of aminocarb, one water‐based, one in a volatile oil of low viscosity, and the third in a non‐volatile oil of high viscosity. For a given volume rate of application, all three mixtures provided similar foliar residues at tree canopy level, but the aqueous and the volatile‐oil based sprays provided significantly lower residues on cut foliage positioned at ground level, than the non‐volatile oil spray mixture.