Air Induction Research Articles

Design and Performance Evaluation of Air Induction (AI) Nozzles to Reduce Drift Potential for Agricultural Unmanned Aerial Vehicles (UAVs)

Design and Performance Evaluation of Air Induction (AI) Nozzles to Reduce Drift Potential for Agricultural Unmanned Aerial Vehicles (UAVs)

Motion model for describing the quantity of air in droplets through changing the structure of air induction nozzle

Air induction nozzles possess good anti-drift performance, the throat and orifice sizes of the nozzles are main design parameters that affecting atomization. Therefore, Venturi tube nozzles and conventional flat fan nozzles were assembled together to investigate the flow rate, droplet size, the quantity of air in droplets affected by single design parameter of nozzles with applying high speed camera and Spraytec laser diffraction system. The results showed that: the flow rate of the air induction nozzle depended only on the throat size of Venturi tube and pressure, and it was proportional to the throat size of Venturi tube at the same pressure; The flat fan nozzle’s orifice size and Venturi tube size significantly affected volume median diameter of droplets, which generally increased after adding surfactant; A new model was established after optimizing classical equation for calculating the percentage of intake air in droplets and studying the effects of throat and orifice size of air induction nozzles on spray characteristics. By variance analysis, it was verified that the new model of quantity of air in droplets produced by all connected nozzles was correct. The calculation showed that the bubbles sizes ranged at 200-900 μm and were in proportion to the droplet size with the percentage of intake air of 10% to 90%. Contrast to the change of volume median diameter and droplet velocity, existence of intake air could influence their change degree to some extent. Keywords: throat orifice, spray characteristic, model of droplet motion, air induction nozzle DOI: 10.25165/j.ijabe.20211405.5513 Citation: Hu J, Liu C X, Wang Z C, Li Y F, Song J L, Liu Y J, et al. Motion model for describing the quantity of air in droplets through changing the structure of air induction nozzle. Int J Agric & Biol Eng, 2021; 14(5): 35–40.

Modelling Spray Pressure Effects on Droplet Size Distribution from Agricultural Nozzles

For spray applications, drop size is the most important feature as it affects all aspects of a phytosanitary treatment: biological efficacy, environmental pollution, and operator safety. In turn, drop size distribution depends on nozzle type, liquid properties, and working pressure. In this research, three nozzles were studied under ordinary working conditions and the effect of pressure on drop size distribution was assessed. The nozzles under test, all from Albuz (France), were an orange hollow cone nozzle ATR 80 (European color code), an air induction flat spray nozzle AVI 11003, and an air induction hollow cone nozzle TVI 8002. The ATR 80 and the TVI 8002 nozzles were tested at four pressure values: 0.3, 0.5, 1.0, and 1.5 MPa; the AVI 11003 nozzle was tested at 0.3 and 0.5 MPa. The drop size measurement technique was based on the liquid immersion method by using a custom-made test bench; spray quality parameters were computed by means of suitable functions written in R language. Results showed that an increase in working pressure caused an increase in drop pulverization regardless of the type of nozzle, and drop pulverization was higher for the turbulence nozzle than for the two air induction nozzles. Based on skewness and kurtosis values, the theoretical gamma distribution was the most adapt to fit the experimental data. The scale parameter showed a decreasing trend with the increase in the pressure, a clear index of higher drop pulverization.

Effect of intermittent normobaric hypoxia exposure on acclimatization to high altitude by air induction

Background: In emergency like condition, defence personnel are deployed to high altitude without proper acclimatization. Maladaption at high altitude leads to high altitude illness like acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE) which hampers the operational capabilities. Aims and Objectives: The aim of the present study was to assess the effect of intermittent normobaric hypoxia exposure (IHE) at sea level on different physiological responses during initial days of acclimatization at 3500m and 4000m altitudes in acute induction. Materials and Methods: The IHE subjects were exposed to 12% FIO2 (equivalent altitude 14500 ft) for 4 hrs/day for 4 consecutive days at sea level and 5th day they were inducted by air to 3500m altitude. Baseline recording of different physiological parameters like cardiovascular, respiratory, oxygen saturation and AMS score were measured at sea level as well as 3500m altitude on daily basis for 6 days to assess acclimatization status. To confirm acclimatization status at 3500m, on fifth day the IHE group subjects were transported by road to 4000m and again measured different basal physiological parameters (like cardiovascular, oxygen saturation and AMS score) for four consecutive days. Results: Different physiological parameters of IHE treated group were stabilized by day 4 of air induction at 3500m altitude. Whereas, at 4000m altitude, these parameters were stabilized by day 2 of induction. Conclusion: Acclimatization schedules of four days at 3500m and two days at 4000m are essential to avoid malacclimatization/or high-altitude illness.

Adjusting Air-Assistance and Nozzle Style for Optimized Airblast Sprayer Use in Eastern Washington Vineyards

<h3>Summary</h3> <h3>Goals:</h3> There are many ways to optimize an airblast sprayer for use in vineyards. Three techniques growers use include: 1) changing nozzle type, 2) reconfiguring or adjusting the nozzles, and 3) adjusting the air-assistance to the droplets during an application. This study evaluated the effects of nozzle type and air-assistance use in airblast sprayers on canopy spray deposition and drift in a Washington wine grape vineyard that is trained to a modified vertical shoot positioning system. <h3>Key Findings:</h3> The one-piece nozzle with air assistance showed consistently high total collected canopy deposition regardless of time of season (early or mid-season). However, drift was reduced when air-assistance was not used. The air induction nozzle had the greatest total collected canopy deposition when using air-assistance during the early season, but had the greatest deposition mid-season without using air-assistance. Drift was reduced when air assistance was not used. Early in the growing season, maximum spray deposition in the fruiting zone of the canopy was achieved using air induction nozzles with air-assistance. However, if one adopted the use of air induction nozzle, <i>without air</i>, that would optimize fruiting zone spray deposition, while reducing captured aerial drift. Mid-growing season, maximum fruiting zone spray deposition without high drift was achieved using air induction nozzles without air-assistance. <h3>Impact and Significance:</h3> An airblast sprayer optimized through changes in nozzle or use of air-assistance can improve spray deposition into the canopy while minimizing drift. Growers can compare and adopt these drift-reduction techniques, i.e., using air induction nozzles and / or turning air-assistance off, to determine which are best suited for their farming practices. Such approach will allow better optimization of the sprayer for their vineyard spray application needs as well as reduce the possible negative impacts associated with off-target chemical deposition on humans and the environment.

Impact of auxin herbicides on Palmer amaranth (Amaranthus palmeri) groundcover

AbstractIn current and next-generation weed control technologies, sequential applications of contact and systemic herbicides for postemergence control of troublesome weeds are needed to mitigate the evolution of herbicide resistance. A clear understanding of the impact auxin herbicide symptomology has on Palmer amaranth groundcover will aid optimization of sequential herbicide applications. Field and greenhouse experiments were conducted in Fayetteville, AR, and a laboratory experiment was conducted in Lonoke, AR, in 2020 to evaluate changes in Palmer amaranth groundcover following an application of 2,4-D and dicamba with various nozzles, droplet sizes, and velocities. Field experiments utilized three nozzles: Extended Range (XR), Air Induction Extended Range (AIXR), and Turbo TeeJet® Induction (TTI), to assess the effect of spray droplet size on changes in Palmer amaranth groundcover. Nozzle did not affect Palmer amaranth groundcover when dicamba was applied. However, nozzle selection did impact groundcover when 2,4-D was applied; the following nozzle order XR &gt; AIXR &gt; TTI reduced Palmer amaranth groundcover the most in both site-years of the field experiment. This result (XR &gt; AIXR &gt; TTI) matches percent spray coverage data for 2,4-D and is inversely related to spray droplet size data. Rapid reductions of Palmer amaranth groundcover from 100% at time zero to 39.4% to 64.1% and 60.0% to 85.8% were observed 180 min after application in greenhouse and field experiments, respectively, regardless of herbicide or nozzle. In one site-year of the greenhouse and field experiments, regrowth of Palmer amaranth occurred 10,080 min (14 d) after an application of either 2,4-D or dicamba to larger than labeled weeds. In all experiments, complete reduction of live Palmer amaranth tissue was not observed 21 d after application with any herbicide or nozzle combination. Control of Palmer amaranth escapes with reduced groundcover may potentially lead to increased selection pressure on sequentially applied herbicides due to a reduction in spray solution contact with the targeted pest.

Alternative Air Induction Melt–Remelt Processing of an Fe3Al–C Intermetallic Alloy: Part I—Mechanical Properties and the Effects of Loading Rate, Heat Treatment and Test Temperatures

Alternative Air Induction Melt–Remelt Processing of an Fe3Al–C Intermetallic Alloy: Part I—Mechanical Properties and the Effects of Loading Rate, Heat Treatment and Test Temperatures

An Experimental Study of the Geometrical Effect on the Performance of an Agricultural Air Induction Nozzle

An Experimental Study of the Geometrical Effect on the Performance of an Agricultural Air Induction Nozzle

On-Farm Evaluation of Nozzle Types for Peanut Pest Management Using Commercial Sprayers

ABSTRACT Growers have rapidly adopted auxin-resistant cotton and soybean technologies. In Georgia, growers who plant auxin-resistant cotton/soybean are required to utilize nozzles that produce larger (coarser) droplets when spraying auxin herbicides to minimize potential off-target movement of pesticides. Consequently, these nozzles are also used in peanut (an important rotational crop with cotton) since changing nozzles between crops is uncommon for growers. However, larger droplets can result in reduced spray coverage which may lead to less effective pest control. Therefore, seven on-farm trials were conducted in commercial peanut fields using commercial sprayers from 2018 to 2020 across four different locations in Georgia to compare the spray performance of air-induction (AI) nozzles that produce very coarse to ultra coarse droplets (VMD50 ≥ 404 microns) with non-AI (conventional flat fan) nozzles that produce medium to coarse droplets (403≥VMD50≥236 microns) for pest management in peanuts. For each trial, test treatments were implemented in large replicated strips where each strip represented a nozzle type. For nozzle comparison, XR and XRC represented non-AI nozzles while TADF, TDXL, TTI, and TTI60 represented the commonly used AI nozzles in these trials. Spray deposition data for each nozzle along with disease ratings, weed and insect control ratings were collected in all on-farm trials. Peanut yield was collected at harvest. Results indicated that the AI nozzles produced larger droplets than the non-AI nozzles in all nozzle tests; however, the spray coverage varied among the nozzle types. Nozzle type did not influence pest (weed, disease and insect) control, or peanut yield (p&amp;gt;0.10) in any of the on-farm trials. These results suggested that peanut growers can utilize these coarser droplet nozzles for pest management in fields with low to average pest pressure during the season. Future research on nozzle evaluation needs to investigate the influence of droplet size, carrier volume, and pressure on coverage and canopy penetration.

Spray nozzle selection contributes to improved postemergence herbicide crabgrass control in turfgrass

For optimum postemergence crabgrass (Digitaria spp.) control, a single quinclorac herbicide application could be properly timed and delivered with spray nozzles that produce spray droplets ranging from very coarse (401-500 μm) to medium (226-325 μm) in size to maximize target coverage and minimize the potential for drift. Crabgrass is an invasive annual grass weed of cool-season turfgrass maintain as lawns, golf courses, and sports pitches. Postemergence herbicide applications for crabgrass control in turfgrass swards often rely on repeated applications for effective control. Optimizing postemergence crabgrass applications can reduce pesticide inputs and contribute to sustainable turfgrass management practices. Two field studies evaluating crabgrass control were conducted in 2020 in a mixed stand of Kentucky bluegrass (Poa pratensis L.) with perennial ryegrass (Lolium perenne L.) in Ohio (USA) and in perennial ryegrass in Pennsylvania (USA). Both sites have histories of natural crabgrass [Digitaria sanguinalis (L.) Scop.] infestation. A postemergence herbicide, quinclorac, was applied at the product label rate and tank-mixed with methylated seed oil at the crabgrass plant stage of three-leaf to one tiller. Different spray nozzles were selected to deliver the following spray droplet classifications and sizes at 275 kPa: Delavan Raindrop 1/4, ultra coarse (&gt;650 μm); TurfJet 1/4TTJO4, extremely coarse (501-650 μm); Air Induction AA8004 or XRTeeJet 8015, very coarse (401-500 μm); XR TeeJet 8008 or GreenLeaf TDAD04, coarse (326-400 μm); XR TeeJet 8004, medium (226-325 μm); and XRTeeJet 8003 fine (145-225 μm). Crabgrass pressure was low in Ohio, and herbicide efficacy at 60 days after treatment was considered acceptable when applied from all spray nozzles that produced spray droplet sizes ranging from ultra coarse to fine. Crabgrass pressure was severe in Pennsylvania, and herbicide efficacy at 60 DAT was considered marginally acceptable when applied from spray nozzles that produced spray droplet sizes ranging from very coarse to medium. Future research should consider cultural practices that would be complementary to postemergence herbicide applications with the goal to reduce pesticide use further and minimize any potential environmental impacts related to spray drift. Highlights - In turfgrass sites with low crabgrass pressure, one postemergence application of quinclorac herbicide could potentially achieve acceptable control with spray nozzles that produce spray droplets ranging from ultra coarse (&gt;650 μm) to fine (145-225 μm). - In turfgrass sites with heavy crabgrass population and pressure, one postemergence application of quinclorac herbicide is best optimized with spray nozzles that produce spray droplets ranging from very coarse (401-500 μm) to medium (226-325 μm). - Overall, turfgrass management practitioners should avoid using spray nozzles that produce a hollow cone spray pattern with ultra coarse (&gt;650 μm) spray droplets which can result in poor or irregular herbicide coverage, or fine (145-225 μm) spray droplets which are subject to potential drift and possible negative off-target effects. - Overall, in an effort to reduce herbicide use for postemergence crabgrass control, a single quinclorac herbicide application could be properly timed and optimized with nozzles that produce spray droplets ranging from very coarse (401-500 μm) to medium (226-325 μm) in size, however, future research should consider cultural practices that would further optimize and also reduce herbicide applications.

Computational study of internal flow characteristics of the air induction nozzle

Air induction nozzle has been used in many applications to decrease the drift potential and increase the crop protection efficacy. The efficient operation and design of these nozzles require understanding the flow characteristics inside the nozzle. Compared to other types of nozzles the studies related to air induction nozzles are very limited especially those concerned with the internal flow. The most important parameter that characterizes the operation of AIN is the air-liquid ratio. There are no studies investigate the effect of internal flow behavior and geometric parameters on the air-liquid ratio. Therefore, the main goal of this study is to investigate the influence of geometric parameters on air-liquid ratio based on the internal flow characteristics. The volume of fluid (VOF) method was used to investigate the internal flow characteristics of an air induction nozzle (AIN). The effect of internal flow characteristics on the air-liquid ratio (ALR) that defined as the ratio between air to liquid mass flowrates was studied. The analysis results of the air-liquid ratio were validated via comparison with the experimental results. The simulations were carried out using the STAR CCM+ software. Different mesh sizes and turbulence models were tested to achieve the best results agree with experimental results. The realizable k-ε turbulence model and mesh with a base size of 0.07 mm at throat diameter of 14 mm and diffuser angle of 20O had the best results so the internal flow was studied using these parameters. The results demonstrated that the performance of AIN represented by ALR was affected by the internal flow characteristics such as velocity, pressure, and film thickness. The effect of diameter ratio (the ratio of throat diameter to pre-orifice diameter) and diffuser angles on the ALR was also investigated. Increasing diameter ratio resulted in increasing ALR at a certain value and then decreased. While increasing diffuser angle resulted in a slight increase in the ALR with further reduction at a diffuser angle of 40O.

Spray drift deposition comparison of fluorimetry and analytical confirmation techniques.

Tracer dyes are often used as surrogates to characterize pesticide spray drift and it is assumed that they accurately reflect analytical measurement of active ingredients; however, the validity of this assumption remains inconclusive. Consequently, the influence of measurement technique on the magnitude of deposition of spray drift was investigated using spray drift samples evaluated by traditional analytical techniques (HPLC-MS/MS) and fluorimetry (1,3,6,8-pyrene-tetra sulfonic acid tetrasodium salt dye tracer). The experiment was conducted in a low-speed wind tunnel under controlled meteorological conditions. The herbicide mesotrione was sprayed through three spray air induction nozzles (anvil deflector flat fan TTI11004; flat fan AI11004; flat fan AIXR11003). Spray drift deposition samples were collected using stainless steel discs pairs placed side by side in the center of the wind tunnel at distances of 5, 10, 20, 30, and 40 ft (1.5, 3.1, 6.1, 9.1, and 12.2m) from the spray nozzle. The analytical technique determined pesticide concentration on one disc per pair, and the other was evaluated by fluorimetry. The experimental results, analyzed using the linear split-split plot model, revealed that median deposition concentrations were 15% higher using the tracer dye fluorescence method relative to the analytical method, potentially due in part to procedural recovery inefficiencies of the analytical method (the mean overall procedural recovery result and RSD was 87% ± 6.4% (n=12). This relationship was consistent and held true for the three nozzle types at all distances within the wind tunnel. © 2021 Society of Chemical Industry.

Evaluation of Drift-Reducing Nozzles for Pesticide Application in Hazelnut (Corylus avellana L.)

Spraying pesticides using air induction nozzles is a well-known method to reduce drift. These drift-reducing nozzles have been tested on many different tree crops (such as apples, citrus, and grapes), but we are still lacking information on their utilization on hazelnut (Corylus avellana L.) groves, although hazelnut is a major nut crop in Italy, and in recent years its cultivated area has been constantly growing. This paper reports a comparison between treatments carried out with cone and flat-fan low-drift nozzles versus two conventional nozzles. The distribution quality, the number of droplets per cm2 of the target area, and the drift in non-target trees adjacent to those treated were evaluated by analyzing the impact of the droplets on water-sensitive papers placed on the tree canopies. The results show that because no significative differences in terms of application quality were found between the tested nozzles, low-drift nozzles can be a good alternative to the standard nozzles to reduce the drift of pesticide applications in hazelnuts without altering the chosen distribution of the pesticide.

Simulation of air-steam gasification of pine sawdust in an updraft gasification system for production of hydrogen-rich producer gas

In this paper, a kinetic model of biomass gasification for H2-rich syngas production is proposed using Aspen Plus process simulator. Having obtained the syngas composition, various parameters and characteristics of the biomass gasification can be determined; they include the gas yield, H2/CO, gas higher heating value (HHV), Carbon conversion efficiency (CCE) and cold gas efficiency (CGE). The gas yield and H2/CO increase as temperature increases from 750 °C to 900 °C. CCE and CGE were also found to increase with increasing temperature. Increasing equivalence ratio (ER) increases the gas yield and CCE due to the decreased concentration of chars in the products. Air induction also decreases the concentrations of combustible gases in the syngas, thereby decreases the HHV of the product gas. H2/CO shows a slight change with ER increasing from 0.1 to 0.4. The detailed analyses performed in the course of the present article reveals that the steam is a feasible gasification agent that can be utilized to generate a syngas with high H2 content. H2 increases from 16.75 vol% to 18.46 vol% with increasing S/B from 0.25 to 1.0. The gas HHV decreases with increasing S/B due to a slight decrease in CH4 content.

Strategies for increasing ferrous sulfate efficacy against dollar spot of creeping bentgrass

AbstractDollar spot (Clarireedia spp.) is a damaging turfgrass disease. Ferrous sulfate (FeSO4) suppresses dollar spot with little risk of resistance. Optimizing FeSO4 applications is crucial for adequate dollar spot suppression. Supplementing FeSO4 applications with chlorothalonil fungicide could also increase efficacy against dollar spot and longevity of disease suppression. Four experiments were conducted to determine the 1) optimal water carrier volume for FeSO4, 2) proper nozzle selection for FeSO4 applications, 3) most efficacious rate combination of FeSO4 and chlorothalonil, and 4) longevity of chlorothalonil efficacy when applied in conjunction with FeSO4 for dollar spot suppression on creeping bentgrass (Agrostis stolonifera L.). These studies were conducted on either putting greens mown at 3.2 to 6.4 mm or fairways mown at 16.5 mm. The following carrier volumes were tested in Experiment 1: 281, 421, 842 and 1684 L ha–1. For Experiment 2, Turbo FloodJet (TF), Turbo TeeJet Induction (TTI), Air Induction Turbo TwinJet (AITTJ), and Extended Range Flat Fan (XRFF) nozzles were used to determine optimal nozzle type. In Experiment 3, chlorothalonil was applied at 0, 2.28, 4.57, 6.86 and 9.16 kg a.i. ha–1 with or without 48.8 kg ha–1 of FeSO4. In Experiment 4, 48.8 kg ha–1 of FeSO4 was applied biweekly and chlorothalonil was curatively applied at 8.2 kg a.i. ha–1 when infection centers per plot reached 30. Water carrier volume had no effect on dollar spot suppression, the AITTJ and XRFF nozzles provided the greatest disease suppression and turf quality, FeSO4 reduced effective chlorothalonil rates by up to 68.5% and FeSO4 increased longevity of chlorothalonil efficacy.

Structural Analysis of Al-CNT Nanocomposite Using X-Ray Diffraction

The development of metal-matrix composites (MMCs) has mainly been driven by the growing needs of modern applications for lightweight materials yet strong enough to withstand high service loading. On the other hand, carbon nanotubes (CNTs) presenting excellent combination of mechanical and physical properties have already performed as an excellent strengthening to reinforce MMCs. In present study, an air induction furnace was used to fabricate aluminum-multiwall carbon nanotubes (Al-MWCNTs) composite. The process was benefited for better dispersion of the CNTs, which was validated during microscopic studies. Additionally, the mechanical properties were significantly augmented i.e., the yield strength from 64±3 to 115±2 MPa, the tensile strength from 82±2 to 125±3 MPa for matrix material and Al-CNTs composite, respectively. The structural analysis including, grain size, crystallite strain and dislocation density were investigated using X-ray diffraction to relate with the improvement in the properties.

Increasing productivity and reducing energy consumption in the pizza industry by the synergetic combination of cooking technologies

Currently, there is a growing interest in increasing productivity while reducing energy consumption and emissions of air pollutants in the restaurant industry. In this regard, we studied the use of hot air, microwaves, superheated steam, infrared, and magnetic induction, and their combinations for the case of the pizza industry. Pizzas cook in hot air impingement ovens were selected as a base case scenario. The quality properties of the pizzas produced by each technology were determined using instrumental techniques. Energy consumption and CO2 emissions were measured as well. Then, we explored the combination of technologies that minimize cooking time and found that it can be reduced by 50% when using infrared in the last stage of the cooking process in hot air impingement ovens. This combination of cooking methods reduces the 27% energy consumption and 27.1% of the CO2 emissions while retaining the desired quality properties of the pizza. Practical applications This work was developed in collaboration with a well-known international manufacturer of cooking equipment. This company, like several other communities, is aware that due to environmental and economic problems, the development of cleaner and more efficient technologies is urgent. However, most of the time, changes in any cooking equipment are related to changes in the quality of the final product. Thus, beyond the need for guiding principles to measure energy efficiency, there is a need for guidelines to measure product quality. Our work addresses those needs for the case of pizza, which is an international bakery product.

Effect of nozzle selection on deposition of thiamethoxam in Actara® spray drift and implications for off-field risk assessment

Off-target drift during pesticide spray applications represents a potential pathway for the introduction of active ingredient into field-adjacent water, soils, and/or vegetation. This study investigated the extent of downwind spray drift deposition of thiamethoxam (as a model insecticide) from an application of Actara® 25WG using standard nozzles (TeeJet XR11003, DG11004, and AIXR11002) onto a fallow field test site in the Midwestern USA. Single broadcast applications at a target rate of 96 g a.i./ha were made uniformly via tractor boom to a mowed stubble plot at a spray volume of 93.5 L/ha. Sampling devices (stainless steel disks, filter paper, and stainless steel rods) were located upwind of the spray swath (as negative control samples), within the spray swath (filter paper only), and downwind (all samplers), perpendicular to the spray swath from 12.5 to 400 ft. (3.8 to 122 m) from the edge of the treated field. Comparison of measured residues from the three types of samplers indicated that filter paper generally had greater variability in results than metal disks. When nozzles were compared, the AIXR11002 air induction nozzle produced less off-field deposition than other nozzles tested.Measured downwind concentrations of thiamethoxam from disk samplers were used to predict distances for mitigating potential effects to honey bees. Based on field-derived models, downwind distances from the spray swath required to reduce exposure levels below levels of concern for honey bees varied from <1 ft. to 148 ft. (0.3 to 45 m) depending on the hazard endpoint and nozzle used. These distances were considerably lower than those predicted using the AgDRIFT model, particularly for distances further downwind. At 400 ft. (122 m), AgDRIFT over-predicted the calculated concentrations by up to a factor of 4.8, 7.2, and 10 for DG11004, XR11003, and AIXR11002, respectively. These data suggest that the AgDRIFT model is less reliable for predicting spray deposition at further downwind distances, with implications for risk assessment.

Junglerice control with glyphosate and clethodim as influenced by dicamba and 2,4-D mixtures

AbstractJunglerice has become a major weed in the mid-south and other areas of the United States. Glyphosate resistance has been documented in junglerice populations and is part of the reason for the increase in its prevalence. However, reduced junglerice control with glyphosate + dicamba and clethodim + dicamba mixtures has been observed in many production fields where glyphosate resistance has not yet evolved. Therefore, research was conducted to assess reduced junglerice control with glyphosate and clethodim when applied with dicamba. Adding dicamba to the spray tank with glyphosate reduced junglerice control by 27%. Adding dicamba to the spray tank with clethodim reduced junglerice control by 11%. The use of Turbo Teejet Induction (TTI) nozzles reduced junglerice control an additional 8% compared to applications with an air induction extended range (AIXR) nozzle. When a drift reduction agent (DRA) was added to dicamba mixtures with glyphosate or clethodim, junglerice control was reduced 36%. Junglerice control was similar with the glyphosate + dicamba treatment compared to the glyphosate + 2,4-D mixture. There was no interaction between nozzles and herbicide treatment. Regardless of herbicide treatment junglerice control was always lower when applied with the ultracourse TTI nozzle. Many applicators in Tennessee prefer to make one application of glyphosate + dicamba in a mixture to save time (authors’ personal experience). These results show that the addition of dicamba to glyphosate or clethodim applied with labeled nozzles and a DRA results in reduced junglerice control and should be avoided.

Spray technology for deposition of droplets on coffee leaves and fruits1

ABSTRACT The correct deposition of spray along the canopy is important for the phytosanitary control in coffee plants; however, the structure of the plant makes this distribution difficult. This study aimed to evaluate the deposition of a tracer on leaves and fruits in coffee cultivation, with respect to the application rate and type of hydraulic nozzle, as well as the use of an electrostatic spraying system. A hydropneumatic sprayer was used, with hydraulic nozzles of empty conical jet of the series TVI (coarse droplets with air induction) or JA (fine droplets), at rates of 200 and 400 L ha-1. An electrostatic system, with SPE-2 nozzle and rate of 200 L ha-1, was also evaluated. The deposition of the tracer on leaves and fruits of the upper, middle and lower thirds of the trees, as well as the losses to the ground in the canopy projection, were quantified using spectrophotometry. The results indicated that the electrostatic application provides a greater deposition on leaves of the upper third than the hydropneumatic application, regardless of the application rate. The use of the TVI nozzle results in a greater deposition on the fruits of the middle third and a greater loss to the ground than the JA nozzle. Although an application rate of 400 L ha-1 results in a greater deposition on the fruits of the middle third than an application rate of 200 L ha-1, it also causes a greater loss to the ground.