Spray Application Techniques Research Articles

Fabrication of a robust superhydrophobic coating exhibiting superior corrosion resistance via spray application technique

Superhydrophobic materials often underperform in practical metal corrosion protection owing to the vulnerability of their rough structures. Additionally, stringent fabrication requirements and high production costs further constrain their development. Consequently, enhancing their mechanical stability with adhesives and streamlining their production processes are focal points of interest. In this research, we employed a combination of modified hydrophobic SiO2 particles and epoxy resin to fabricate a durable, abrasion-resistant superhydrophobic coating on a Q235 steel substrate using a one-step spray technique. Throughout the experimental phase, we systematically investigated the ideal ratio of hydrophobic SiO2 particles to epoxy resin within the coating, comprehensively assessing its wettability, mechanical stability, and corrosion resistance. The ideal hydrophobic SiO2 content was found to be 65%, achieving a contact and sliding angles of 158.9° and 4.27°, respectively. This coating maintained its superhydrophobicity after 4.5 m of mechanical abrasion and 40 tape peeling cycles. In terms of corrosion protection, the coating exhibited an impedance two orders of magnitude higher than that of the bare Q235 substrate. It significantly reduced the corrosion current density by two orders of magnitude, with a corrosion inhibition efficiency of 99.36%. Moreover, the superhydrophobic coating retained its properties after 12 h of immersion in strong acids and bases, 30 d in a 3.5 wt% NaCl solution, and outdoor exposure, demonstrating a degree of anti-fouling capability and excellent self-cleaning properties. Notably, the room-temperature, one-step spray method facilitates practical application on various substrates, improving production efficiency and expanding usability.

Omniphobic coatings based on functional acrylic polymer

Omniphobic coatings were prepared on flat surfaces using a functional acrylic polymer and common micron sized inorganic particles by a simple spray application technique. This coating comprises of a blend of functional acrylic polysiloxane polymer and liquid epoxy resin as a primer base coat followed by spray application of a mixture of organosilanes and inorganic microparticles. The microparticles are fillers commonly used in the paint and coating industry. The resulting surface has the desired surface energy and surface morphology to enable liquid repellency with contact angles of ∼150° for water and 142° for diiodomethane with a roll off angle of <5°. Scanning Electron Microscopic (SEM) and Atomic Force Microscopy (AFM) analysis were performed to study surface morphology. This coating can be applied on large areas and can be cured under ambient conditions. This omniphobic coating is robust, free of nanoparticles and can be used for potential applications in the field of self-cleaning coatings, anti-microbial coatings, and easy cleaning coatings.

Developing of New Technologies Driving Advances in Precision Agriculture to optimise inputs and reduce environmental footprint

Technological advances in the agri-tech sector offer the opportunity for food production systems to contribute to achieving global policy aims such as achieving net zero carbon systems and reducing environmental footprint through eliminating harmful emissions and increasing biodiversity. A range of sensors can detect crop health and stress due to biotic and abiotic threats, often with an early detection which permits appropriate action to be taken before crop yield is affected or pest and disease pressure cannot be controlled without the use of synthetic pesticides. Detection technology uses imaging techniques, often beyond the visible spectrum, detection of volatile compounds using e-nose techniques and real time molecular diagnostic techniques to identify plant pathogens collected in air samples. The data generated by such technologies relies on connectivity of the hardware and subsequent analytical processes to provide growers with temporal and spatial information. It is possible to identify plant locations with great accuracy, even with satellite systems, which permits precision application of crop inputs, such as fertilisers and pesticides, directly to the plant or crop area as required. Spray application techniques can now treat individual plants, both crop and weeds, using data acquired to control the flow to individual nozzles

Comparative Insecticide Application Techniques (Micro-Sprinkler) Against Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Highbush Blueberry.

Drosophila suzukii (Matsumura), spotted-wing drosophila, is a major pest in small fruit crops including highbush blueberry. Controlling D. suzukii is challenging and chemical control is the main method to manage D. suzukii populations. Growers have expressed interest in using micro-sprinklers as an alternative method to apply insecticides. The current study aimed to evaluate if insecticide applications using micro-sprinklers can be used as an alternative method to protect the fruit from D. suzukii egg-laying. Modeling was used as an additional tool to parameterize the relative insecticide efficacy on oviposition. Field measurements of different treatments were conducted over periods of eleven days on commercial-standard highbush blueberry. Cyantraniliprole and spinetoram were applied using both a micro-sprinkler and a backpack sprayer. Treatments of Chromobacterium subtsugae and zeta-cypermethrin were only applied using a backpack sprayer. Both cyantraniliprole and spinetoram treatments resulted in moderate suppression of D. suzukii egg-laying. No statistical significance was found between micro-sprinkler and backpack sprayer applications for these two insecticides. Zeta-cypermethrin treatments using a backpack sprayer resulted in the most significant suppression of D. suzukii egg-laying over eleven days, while C. subtsugae was less effective at preventing D. suzukii egg-laying. Modeling simulations estimate the impact of the control methods on D. suzukii populations dynamics and simulation outputs indicated that backpack sprayers reduced D. suzukii populations at more pronounced levels compared to micro-sprinkler applications. The present study indicates that there is an underlying value of micro-sprinkler systems as an alternative and rapid spray application technique to help suppress D. suzukii pest populations during high-pressure periods in highbush blueberry production.

Generating prediction model of fan width by optimizing paint application process for Electrostatic Rotary Bell atomizer

Fan Width plays a critical role in the paint spray application process, so much so that it can be represented as the backbone of the process. In this process, a high voltage Rotary atomizer along with shaping air discharge paint particles to create a spray pattern which defines the basic fan width. Many painting industries practice a "trial and error" method to determine the fan width of their coating process which can be inconsistent and lead to poor quality results. A predictive model for this dynamic fan width pattern, based on the application inputs, can make a significant efficiency improvement in the spray application technique to deliver a uniform paint distribution across the painted object. This research presents a fan width prediction model for a specific rotary bell atomizer and a waterborne automotive OEM paint color. A full factorial Design of Experiement has been performed to analyze factors that influence the dynamic spray pattern. From this a linear regression model has been derived to calculate the fan width which varies within 2.5 cm to maintain manufacturing tolerance. The model has been verified statistically and experimentally, so that it can eliminate the trial-and-error method to save time and cost.

Integrating Trissolcus japonicus (Ashmead, 1904) (Hymenoptera: Scelionidae) into Management Programs for Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae) in Apple Orchards: Impact of Insecticide Applications and Spray Patterns.

Simple SummaryIn the United States, the invasive brown marmorated stink bug has caused economic damage to specialty crop and tree fruit industries, including apples. Since its arrival, research has shown that altered spray programs can control brown marmorated stink bug as well as spraying an entire apple orchard, resulting in less insecticide use. Here, we evaluated three spray programs and four commonly used insecticides in combination for their impact on a non-native wasp, the samurai wasp, that parasitizes egg masses of this invasive stink bug. We exposed adult samurai wasps to egg masses from our treatments, including unsprayed areas, and recorded their survival as well as how many wasps emerged afterward. In addition, we recorded how immature wasps developing inside egg masses responded to these treatments. We found that only one insecticide had negative impacts on the adult wasps while the majority of insecticides tested impacted their offspring’s emergence. In general, insecticides tested minimally impacted wasps already developing inside egg masses treated with insecticides. These data support the idea that growers can simultaneously manage brown marmorated stink bug and conserve beneficial insects, such as the samurai wasp, while reducing insecticide use by using improved pest management tactics.Halyomorpha halys (Stål, 1855) (Hemiptera: Pentatomidae) is an invasive species in the United States, where it has caused significant damage to specialty crops, including apples. While integrated pest management techniques have been developed for H. halys in apple, including spray application techniques, it is unknown how these techniques affect foraging, adventive Trissolcus japonicus (Ashmead, 1904) (Hymenoptera: Scelionidae), and its offspring. In this study, egg masses (unparasitized and 2 and 7 day parasitized pre-treatment) were placed in apple orchards in treated and untreated locations that received full block insecticide applications or reduced application techniques, including border row or alternate row middle applications. Bifenthrin, thiamethoxam + λ-cyhalothrin, clothianidin, and methomyl were evaluated. Egg masses were retrieved 24 h after spray applications. For 2 and 7 day parasitized pre-treatment, adult T. japonicus emergence was recorded from each egg mass. For unparasitized egg masses, T. japonicus females were given 24 h to forage and oviposit on post-treatment egg masses with female survivorship, and adult emergence from egg masses was recorded. Female survivorship was significantly lower on post-treatment egg masses retrieved from areas receiving bifenthrin applications. Emergence from post-treatment egg masses was affected by thiamethoxam + λ-cyhalothrin, bifenthrin, and methomyl in some treated areas, whereas less impact was observed on 2 and 7 day pre-treatment parasitized egg masses in general. These data provide further insights into H. halys management and the potential impact of T. japonicus in sprayed orchard agroecosystems.

Effect of Spray Application Technique on Spray Deposition and Losses in a Greenhouse Vegetable Nursery

The cultivation of vegetables in greenhouses requires seedlings produced in nurseries with high levels of practice specialisation. The nurseries are dedicated to the early stages of growth, from sowing to the first leaves. There, the seeding density and the hydro-climatic conditions favour diseases. Plant protection treatments are carried out with the use of low-cost machines, whose efficiencies and safety conditions depend on the workers’ ability. The irrigation system with a mechanised horizontal spray boom could be an alternative solution to the hand-held spray gun. This research aimed to investigate the use of a horizontal boom sprayer for the distribution of pesticides in different pressure conditions and forward speeds compared with a spray gun, in relation to tomato growth stages. The tests were carried out on tomato seedlings grown in polystyrene seeding boxes and arranged on hanging benches. Deposits on the seedlings (µL cm−2) and losses in the soil (µL cm−2) were assessed by means of standard colorimetric analysis. In order to reduce the environmental pollution and increase the sustainability of the treatments, the pressure at the horizontal spray boom should be reduced and the arrangement of the outermost nozzles may also be better set on the boom.

Reduced Herbicide Antagonism of Grass Weed Control through Spray Application Technique

Dicamba and 2,4-D tolerance traits were introduced to soybean and cotton, allowing for over the top applications of these herbicides. Avoiding antagonism of glyphosate and clethodim by dicamba or 2,4-D is necessary to achieve optimum weed control. Three field studies were conducted in fallow fields with broadleaf signalgrass (Urochloa platyphylla) and Italian ryegrass (Lolium perenne ssp. multiflorum) pressure. A tractor-mounted dual boom sprayer was modified to spray one of three application methods: (1) two herbicides tanked-mixed (TMX); (2) two herbicides in separate tanks mixed in the boom line (MIL); and (3) two herbicides in separate tanks applied through separate booms simultaneously (SPB). One study compared the three application methods with sethoxydim applied with bentazon, the second compared clethodim applied with dicamba or 2,4-D, and the third compared glyphosate applied with dicamba or 2,4-D. In most cases over all three trials, there was a 7–15% increase in efficacy when using the SPB application method. Antagonism of all the herbicide combinations above was observed when applied using the TMX and MIL methods. In some cases, antagonism was avoided when using the SPB method. The separate boom application method increased efficacy, which allowed herbicides to be used more effectively, resulting in improved economic and environmental sustainability of herbicide applications.

Revisiting Sustainability of Fungicide Seed Treatments for Field Crops

The use of fungicide seed treatment (FST) is a very common practice worldwide. The purported effectiveness of many fungicides in providing broad-spectrum and systemic control of important diseases and the perception that FST reduces overall pesticide use, hence lowering environmental impacts, have greatly promoted the use of FST in the last five decades. Since there have been rapid advancements in the types, formulations, and application methods for seed treatments, there is a need to re-evaluate the benefits versus the risks of FST as a practice. While the use of seeds treated with neonicotinoid insecticides has come under scrutiny due to concern over potential nontarget effects, there are knowledge gaps on potential negative impacts of FST on operators' (those who apply, handle, and use treated seeds) health and nontarget soil organisms (both macro- and microorganisms). Here we review existing knowledge on key fungicides used for seed treatments, benefits and risks related to FST, and propose recommendations to increase benefits and limit risks related to the use of FST. We found FST is applied to almost 100% of sown seeds for the most important arable crops worldwide. Fungicides belonging to 10 chemical families and with one or several types of mobility (contact, locally systemic, and xylem mobile) are used for seed treatment, although the majority are xylem mobile. Seed treatments are applied by the seed distributor, the seed company, and the farmer, although the proportion of seed lots treated by these three groups vary from one crop to another. The average quantity of fungicide active ingredient (a.i.) applied via seed treatment depends on the crop species, environment(s) into which seed is planted, and regional or local regulations. Cost-effectiveness, protection of the seed and seedlings from pathogens up to 4-5 weeks from sowing, user friendliness, and lower impact on human health and nontarget soil organisms compared with foliar spray and broadcast application techniques, are among the most claimed benefits attributed to FST. In contrast, inconsistent economic benefits, development of resistance by soilborne pathogens to many fungicides, exposure risks to operators, and negative impacts on nontarget soil organisms are the key identified risks related to FST. We propose eight recommendations to reduce risks related to FST and to increase their benefits.

Operator exposure to spray deposits using various application techniques in paddy fields

Purpose The safety of operators handling pesticides is still one of the main problems facing Thai agricultural workers. The purpose of this paper is to study the safety of farmers and the techniques recommended to farmers by the Department of Agriculture in Thailand, i.e. spraying to achieve optimum spray volume with consideration for wind direction – henceforth referred to as officer techniques. Design/methodology/approach Operator exposure was detected by verifying the deposition of dye tracer on the coveralls worn by ten spray service team leaders, for all applications between May and June 2017. For each technique, a total of 15 patches were attached at the lower legs, thigh, chest, forearms, upper arms, hands, face, forehead and back. Each individual technique was performed four times in the area of 1,800 m2. Findings The results showed that the deposits with the farmers’ techniques was much higher than with officers’ techniques ranging from 2.32 to 23.91 times at the tillering stage and 9.90 to 56.79 times at the booting stage, respectively. These results indicate that the spray application technique has a considerable potential for reducing the contamination of spray operators by 56.96–98.23 percent. Operator safety can be considerably improved by the spray application technique employed. Without any investment and changing equipment, only by considering wind direction, officers’ techniques could avoid much deposition, which is the most practical operation in the field. The boom sprayer as a novel recommended technique is an alternative giving a positive result and it can be a substitute for the conventional method. Furthermore, the authors must pay attention to personal protective equipment (PPE) because depositions were discovered on the whole of the bodies of those tested. PPE is the best way to protect an operator from pesticide contamination. Originality/value Operator exposure data can be helpful in further development of exposure models and databases for risk assessment and pesticide registration in Thailand.

Biomechanical Comparison of Fibrin Sealants for Mesh Fixation

Adhesive use for fixation in hernia repair allows for complete and immediate mesh surface area adherence. Little is known about the fixation strengths of the products and application methods available. The purpose of this study was to compare the immediate and early strength of fixation of Tisseel™ and Evicel™ using hand and spray application techniques. Sixteen Mongrel swine underwent implantation of large-pore, mid-weight polypropylene mesh fixated with either Tisseel™ or Evicel™, applied by hand or with a spray apparatus. Time points studied were zero and four days. All samples underwent lap shear testing to quantify the strength of the mesh-tissue interface as an indicator of mesh fixation strength. Thirty Day 4 and 16 Day 0 samples were tested. Manually applied Tisseel™ mean fixation strength was 2.05 N/cm at Day 0 and 6.02 N/cm at Day 4. Sprayed Tisseel™ had mean fixation strength of 1.22 N/cm at Day 0 and 7.21 N/cm at Day 4. Manually applied Evicel™ showed mean fixation strength of 0.92 N/cm at Day 0 and 6.73 N/cm at Day 4. Mean fixation strength of sprayed Evicel™ was 0.72 N/cm at Day 0 and 6.70 N/cm at Day 4. Analysis of variance showed no difference between groups at Day 0 or Day 4. Immediate strength of mesh fixation could have significant implications for early recurrence and mesh contraction. This study demonstrates that no difference exists in immediate or early fixation strength between these two brands of sealants or their method of application.

Comparison of Spray Configurations in a Spray Cabin Design for Ornamental Potted Plants: A Proof-of-Concept Study

Abstract. With the implementation of integrated pest management in the European Union, growers are obliged to manage pests in a manner that minimizes health and environmental risks due to the use of plant protection products. Among other approaches, this goal can be achieved by optimizing spray application techniques. As an alternative to the predominantly used handheld equipment, such as spray guns, spray boom systems might substantially improve spray application, and thus crop protection management, in greenhouses. The aim of this proof-of-concept study was to compare different spray configurations in a spray cabin designed to spray ornamental potted plants that are moving on a conveyor belt. Seven different spray configurations were examined for optimal spray deposition in two crops (azalea and ivy) using mineral chelate tracers. The deposition tests showed that the presented prototype can satisfactorily spray potted plants up to a height of 25 cm including the pot height. The best spray deposition was found with two flat-fan nozzles oriented 35° upward, spraying at 1.0 bar and an application rate of 1047 L ha-1. This configuration increased deposition on the underside of the leaves and at the middle foliage layer compared to the other configurations that were evaluated. The spray cabin with a band spray setting has potential to mitigate the use of plant protection products and achieve a more efficient spray application compared to traditional handheld techniques and broadcast spray boom techniques. Keywords: Crop protection, Integrated pest management, Nozzle type, Spray deposition.

Effect of spray application techniques on spray deposits and residues of bifenthrin in peas under field conditions.

Five spraying techniques were evaluated for the coverage of bifenthrin on peas under open field conditions. Ultra-low volume sprayer (ULVA) and Ground hydraulic motor with conventional spray gun (GMG) gave number mean diameters (NMDs) from 27 to 68 and from 33 to 73 N/cm2 with volume mean diameter (VMD) from 50 to 120 and from 320 to 508, respectively. Homogeneity factor values were 2, 2, 2.5, 2.8, and 13.5 in ULVA, Domestic modification of the ground hydraulic motor sprayer with one nozzle (GMO), Ground hydraulic motor sprayer with vertical boom (GMV), Motorized knapsack mist blower sprayer (MKM) and GMG. The percentages of the lost spray in the ground were 23, 39, 21, 24, and 36% for ULVA, MKM, GMG, GMO and GMV, respectively. An analytical method was developed using QuEChERS and GC-ECD to determine the initial deposit of bifenthrin in pods and leaves. Initial deposits were from 0.006 to 0.05 mg/kg in pods and from 0.03 to 0.66 mg/kg in leaves. The most efficient technique was single nozzle Twinjet, followed by the motorized knapsack sprayer.

Spray Deposition with Conventional Nozzles, Low-Drift Nozzles, or Permanent Sprinklers for Controlling Apple Orchard Pests

Field experiments were conducted to compare deposition of spray on leaves in a high-density apple orchard for different spray application systems. A permanent sprinkler system was installed for pesticide applications. Sprinklers were installed above the canopy centered on the tree row and compared to a conventional radial sprayer with reduced airflow and fitted with conventional or low-drift nozzles. The ratio of bottom to top of leaf deposit was closer to 1 with the low-drift nozzles, greater than 1 with the conventional nozzles, and close to 0 with the sprinklers. Leaf coverage with the low-drift nozzles was not statistically different from deposits with conventional nozzles in all tree locations on both top and bottom surfaces of the leaves except in the lower part of the trees close to the trunk, where low-drift nozzles produced higher deposits. Overall, the low-drift nozzles produced less variability in deposits among the positions in the trees. On the trees as a whole, sprinklers and low-drift nozzles deposited more spray than conventional nozzles. Contrary to our initial hypothesis, differences in spray application technique efficacy were more important for insect control than for apple scab control but were generally small. Insect control with conventional nozzles proved slightly better than with low-drift nozzles, which were in turn slightly better than the sprinklers. Apple scab control under severe infection conditions was equivalent in all three systems, which suggests that pesticide coverage with sprinklers, which is close to a rain pattern, effectively reached infection sites despite minimal coverage of the abaxial leaf surfaces. The absence of pesticide residue on the abaxial surfaces of sprinkler-treated leaves may also serve as a refuge for predatory mites. These results show that perfect coverage is not an absolute requirement for good pesticide efficacy, as exemplified by our results on the efficacy of sprinklers for applying pesticides. Pesticide efficacy results from appropriate coverage of the target, with the target defined by pest epidemiology, crop status, and meteorological conditions.

Target precision and biological efficacy of two nozzles used for precision weed control

Site-specific weed control at a high resolution level imposes high demands on the application technology in order to obtain a precise application and control of weeds in areas where threshold values are exceeded and to limit waste of herbicide in areas outside the intended sprayed area. The approach reported in this paper was to divide the field into small cells with a width of 250 mm. The other dimension in the longitudinal direction could be varied. The aim of the part of the study described in this paper was to test the precision of commercially available spray application techniques for the purpose of applying herbicides to decimetre-size cells. Two narrow angled nozzles, a TeeJet 4002 and a TeeJet 6502 were used in combination with the WeedSeeker valve. Two types of tests were performed, biological efficacy tests and droplet distribution tests. In the biological efficacy tests, efficacy of cell application at various places inside and at the border zone of the intended sprayed cell was compared with efficacy of a continuous application. The results of applications at 1 and 2 m/s showed that biological efficacy at positions in the central part of 160 mm long cells were comparable to efficacy obtained at the same positions using continuous application. In the spray distribution test, number and area of droplets in 10 × 10 mm cells were measured at different application speeds. From the distribution test, the displacement of the spray swath at increasing application speed could be described. Both efficacy and distribution tests showed a high precision targeting decimetre-size cells with the tested nozzle/valve combination at a low application speed. Increasing the speed above 2 m/s, increased variability of the application.

Spray distribution evaluation of different settings of a hand-held-trolley sprayer used in greenhouse tomato crops.

Hand-held-trolley sprayers have recently been promoted to improve spray application techniques in greenhouses in south-eastern Spain. However, certain aspects remain to be improved. A modified hand-held-trolley sprayer was evaluated under two different canopy conditions (high and low canopy density) and with several sprayer settings (nozzle type, air assistance and spray volume). In this study, the deposition, coverage and uniformity of distribution of the spray on the canopy have been assessed. The deposition on leaves was significantly higher when flat-fan nozzles and air assistance were used at both high and low spray volumes. No differences were detected between the reference system at a high spray volume and the modified trolley at a low spray volume. Flat-fan nozzles with air assistance increased penetrability into the canopy. Air assistance and flat-fan nozzles allow volume rates to be reduced while maintaining or improving spray quality distribution. The working parameters of hand-held sprayers must be considered to reduce environmental risk and increase the efficacy of the spraying process. © 2015 Society of Chemical Industry.

Spray deposition assessment using different application techniques in artificial orchard trees

Seven orchard spray application techniques were compared in terms of within-tree deposition quality and off-target losses to the ground and behind the target trees. The studied spray techniques included different sprayer types, fan speeds and air deflector settings. An artificial pear canopy was realized for this purpose. Filter papers and a multiple tracer methodology were used to evaluate deposition. All measurements were conducted indoor and will be used as an input and to validate a CFD orchard spray model.Results showed that spray application technique has an effect on spray deposition. Sprayer design caused major differences in spray distribution and off-target losses. A sprayer with individual spouts gave the highest deposits on the tree (0.15 L), followed by an axial sprayer (0.10–0.12 L). Changing settings on the axial sprayer only caused minor differences, although the high fan gear performed significantly better than the low gear. Lowest tree depositions were found for a cross-flow sprayer (0.08–0.09 L). A significant portion of the spray liquid was lost to the ground and directly behind the trees with all spray techniques. The axial fan sprayer and the sprayer with individual spouts caused higher ground deposits than the cross-flow sprayer. The cross-flow sprayer on the other hand gave higher losses behind the trees, especially when a high fan speed was applied.

Advanced Technologies for the Improvement of Spray Application Techniques in Spanish Viticulture: An Overview

Spraying techniques have been undergoing continuous evolution in recent decades. This paper presents part of the research work carried out in Spain in the field of sensors for characterizing vineyard canopies and monitoring spray drift in order to improve vineyard spraying and make it more sustainable. Some methods and geostatistical procedures for mapping vineyard parameters are proposed, and the development of a variable rate sprayer is described. All these technologies are interesting in terms of adjusting the amount of pesticides applied to the target canopy.

Evaluation of disposable diaper construction hot melt pressure‐sensitive adhesives using blends of olefinic block copolymer and amorphous polyolefin polymers—Adhesive performance, sprayability, and viscoelastic characteristics

ABSTRACTPressure‐sensitive adhesives (PSAs) used in disposable diaper construction have been formulated using blends of olefinic block copolymer (OBC) and an ethylene–propylene (PE‐PP) amorphous polyolefin (APO) polymer, with three different unsaturated hydrocarbon resins (with varying aromatic content), and also with two different saturated aliphatic hydrocarbon resin (with varying cycloaliphaticity). The viscoelastic properties of theses PSA formulations were studied using dynamic mechanical analysis (DMA). Viscosity profiles at five different temperatures were generated to better understand the application window for the resulting adhesive formulation. Rheology master curves were generated using time–temperature–superposition analysis and correlated with the processability characteristics. Adhesives used in disposable diaper construction were applied between a polyethylene backing and a nonwoven substrate with an air‐assisted spiral spray application technique on an Acumeter Spray Coater. After the adhesive was applied, peel adhesion testing on the samples was performed. It has been observed that the OBC/PE–PP‐based disposable diaper construction PSA has a lower application temperature along with wider tolerance for hydrocarbon resin chemistries, especially for the saturated aliphatic resin‐based PSA formulations. Based on the coating parameters used, it has been learned that the adhesive formulations seem to show a higher shear rate at the nozzle, but Reynolds number calculated indicated no major turbulence occurring at the nozzle during spraying. Very good spray patterns were obtained for the olefinic polymer‐based PSA formulations. Disposable diaper construction article showed good adhesive peel properties, especially for the adhesive formulations containing saturated aliphatic hydrocarbon resin, which were comparable to the SBS‐based control. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3311–3318, 2013

Improving the biocontrol potential of entomopathogenic nematodes against Mamestra brassicae : effect of spray application technique, adjuvants and an attractant

Steinernema carpocapsae Weiser, an entomopathogenic nematode (EPN), is a potential biological control agent for the cabbage moth (Mamestra brassicae L.). This research aimed to identify a suitable spray application technique, and to determine whether yeast extract added to an EPN spray has an attracting and/or a feeding stimulant effect on M. brassicae. The biological control capabilities of EPN against this pest were examined in the field. Good coverage of the underside of cauliflower leaves, the habitat of young instar larvae (L1-L4) of M. brassicae was obtained using different spray boom configurations with vertical extensions that carried underleaf spraying nozzles. One of the configurations was selected for field testing with an EPN spray. Brewer's yeast extract stimulated larval feeding on leaves, and increased the mortality of these larvae when exposed to EPN. The field trial showed that a spray application with S. carpocapsae, Addit and xanthan gum can effectively lower the numbers of cabbage heads damaged by M. brassicae. Brewer's yeast extract did not significantly increase this field performance of EPN. Steinernema carpocapsae, applied with an appropriate spray technique, can be used within biological control schemes as part of a resistance management programme for Bt.