Conventional Spray Application Research Articles

Evaluation of an electrostatic spray charge system implemented in three conventional orchard sprayers used on a commercial apple trees plantation

Electrostatic sprayers can be an option for increasing the effectiveness of treatments and reducing pesticide consumption, but it still requires more verifications, especially in orchards. The spray deposition performances of three different electrostatic sprayers design were compared for apple tree pesticide application, all of them used with the electrostatic system activated and disactivated, as conventional spray application. Despite designs of particular type sprayers were unique, no significant differences were observed in the normalized deposition and droplets density between the conventional and electrostatic spray methods of the same sprayer, but differences were found between the vertical boom and the pneumatic sprayer in terms of coverage. The normalized deposition values of the three sprayers were very similar, ranging between 1.0 and 1.5 μg cm−2. However, the vertical boom sprayer produced the highest spray coverage, followed by the multi-fan sprayer. In general, the measured values of coverage and deposit obtained were in the three cases similar, independently on the use or not of the electrostatic device, being the sprayer type more affecting parameter rather than the electrostatic charging system. Differences in spray deposition qualities on apple trees were observed among three types of sprayers, but were not for the same sprayer with and without activation of the electrostatic charging system. Appropriate design of orchard sprayers according to the canopy structure seems to be more effective rather than the implementation of electrostatic spray charge system to achieve the European challenge of 50% reduction of pesticides by 2030.

The effect of insecticide application by dropleg sprayers on pollen beetle parasitism in oilseed rape

Dropleg sprayers apply pesticides below the flower horizon of oilseed rape plants and thus reduce unwanted side effects on pollinating insects. Whether this technique benefits parasitoids of seed and pollen feeding insect pests has not been studied earlier. To answer this question, we first assessed the vertical distribution of pests and parasitoids using a portable aspirator. In addition, parasitism rates of pollen beetle, Brassicogethes aeneus Fabricius (Coleoptera: Nitidulidae), by the larval parasitoid Tersilochus heterocerus Thomson (Hymenoptera: Ichneumonidae) were compared in conventional and dropleg sprayed fields over four years (2016–2019), using the neonicotinoids thiacloprid and acetamiprid. Our results show that seed and pollen feeders were mainly found in the flowering canopy, while the predominant location of parasitoids was species-specific. Among pollen beetle parasitoids, Phradis interstitialis Thomson (Hymenoptera: Ichneumonidae) was more abundant below flowering canopy (63% of total catch), whereas T. heterocerus was mainly caught in the flowering canopy (84% of total catch). In the spraying experiments, average parasitism rates of pollen beetles by T. heterocerus ranged between 55 and 82% in the untreated controls. In the dropleg spray treatments, parasitism rates did not differ significantly from control levels, with the exception of thiacloprid application in 2019. In contrast, conventional spray applications resulted in a reduction of parasitism rates by up to 37% compared to the control for at least one of the insecticides in three out of four years. The impact of conventional application differed between years, which may be explained by the temporal coincidence between spray application and the immigration of parasitoids into the crop. We conclude that dropleg spraying exerts lower non-target effects on the main biological control agent of pollen beetle.

Control of Insect Pests and Diseases in an Ohio Fruit Farm with a Laser-guided Intelligent Sprayer

Laser-guided variable-rate intelligent spray technology is designed to significantly reduce pesticide use with a positive impact on the environment. However, there have been no reports on applying this technology to commercial fruit farms. Comparative experiments of intelligent variable-rate and conventional constant-rate spray applications for pesticide use and pest control were conducted at a fruit farm in Ohio during two consecutive growing seasons. Apple (Malus pumila), peach (Prunus persica), blueberry (Vaccinium section Cyanococcus), and black raspberry (Rubus occidentalis) were used for the tests. Pest severity of codling moth (Cydia pomonella), oriental fruit moth (Grapholitha molesta), scab (Venturia inaequalis), and powdery mildew (Podosphaera leucotricha) in apple; oriental fruit moth, brown rot (Monilinia fructicola), and powdery mildew (Podosphaera pannosa) in peach; spotted wing drosophila (Drosophila suzukii), mummy berry (Monilinia vaccinii-corymbosi), and phomopsis (Phomopsis vaccinii) in blueberry; and anthracnose (Elsinoe veneta) in black raspberry were assessed. There was equal severity of pests between intelligent and conventional spray applications, whereas the intelligent spray reduced pesticide use by 58.7%, 30.6%, 47.9%, and 52.5% on average for apple, peach, blueberry, and black raspberry, respectively. These results illustrate that intelligent spray technology is more environmentally friendly than conventional standard spray technology and equally or more effective for control of insect and disease pests in fruit production.

Development of canopy vigour maps using UAV for site-specific management during vineyard spraying process

Site-specific management of crops represents an important improvement in terms of efficiency and efficacy of the different labours, and its implementation has experienced a large development in the last decades, especially for field crops. The particular case of the spray application process for what are called “specialty crops” (vineyard, orchard fruits, citrus, olive trees, etc.) represents one of the most controversial and influential actions directly related with economical, technical, and environmental aspects. This study was conducted with the main objective to find possible correlations between data obtained from remote sensing technology and the actual canopy characteristics. The potential correlation will be the starting point to develop a variable rate application technology based on prescription maps previously developed. An unmanned aerial vehicle (UAV) equipped with a multispectral camera was used to obtain data to build a canopy vigour map of an entire parcel. By applying the specific software DOSAVINA®, the canopy map was then transformed into a practical prescription map, which was uploaded into the dedicated software embedded in the sprayer. Adding to this information precise georeferenced placement of the sprayer, the system was able to modify the working parameters (pressure) in real time in order to follow the prescription map. The results indicate that site-specific management for spray application in vineyards result in a 45% reduction of application rate when compared with conventional spray application. This fact leads to a equivalent reduction of the amount of pesticide when concentration is maintained constant, showing once more that new technologies can help to achieve the goal of the European legislative network of safe use of pesticides.

Evaluation of attract-and-kill strategy for management of cocoa pod borer, Conopomorpha cramerella, in Malaysia cocoa plantation

In South-East Asia, cocoa production is dramatically affected by cocoa pod borer (CPB) infestations. As an alternative tool to chemical control, the efficacy of attract-and-kill strategy (CPB sex-pheromone as attractant and Delta trap without sticky liner sprayed with cypermethrin solution as killing station) was evaluated and compared with current standard CPB management approach as control treatment during two main cocoa harvest seasons in Malaysia (with 100 µg and 33.3 µg CPB-pheromone loading per station, respectively). In both seasons, attract-and-kill strategy was highly effective at reducing male flight activity (p < 0.05) in attract-and-kill plots comparing with standard CPB management plots. For the percentage of CPB-infested pods, the attract-and-kill strategy (100 µg) was as good as the conventional pesticide spray applications of cypermethrin (p = 0.083) in first season. However, it was significantly (p = 0.021) reduced in the second season with lower pheromone loading (33.3 µg), indicating that this semiochemical based strategy is far superior to and more feasible than the currently applied conventional synthetic pesticide treatment and is therefore a good alternative in CPB integrated pest management.

Herbicidal control of bridal creeper (Asparagus asparagoides) in an ecologically sensitive environment

Asparagus asparagoides (bridal creeper) is a highly invasive noxious environmental weed in southern Australia. It poses a severe threat to biodiversity and conservation in temperate natural ecosystems. Pterostylis arenicola, a threatened terrestrial orchid endemic to South Australia, is directly imperilled by this weed in most of its remnant populations. The coincident growth phenologies of orchid and weed make for an ecologically sensitive environment when considering methods of weed control or eradication. To minimise impact on the orchid and its ecosystem, this paper examines the efficacy of herbicide application for A. asparagoides control using the weed wiping technique, comparing it to the conventional spray application method. The most prolonged control of A. asparagoides was achieved after a single wipe-application of 1.5 g a.i. (active ingredient) L−1 metsulfuron methyl, either alone or in combination with 120 g a.i. L−1 glyphosate, both treatments giving significantly better weed control five years after treatment than comparable spray applications. An investigation of the effect of glyphosate on cultures of the mycorrhizal fungus isolated from P. arenicola indicated a significant decline in mycelial growth with increasing herbicide concentration over the range 0.5–3.0 kg a.i. ha−1. These results provide further incentive for the use of ecologically sensitive herbicide application techniques, such as weed wiping, in areas of high conservation concern.

An empirical model based on phenological growth stage for predicting pesticide spray drift in pome fruit orchards

An innovative spray drift model is developed to describe downwind deposits of pesticides applied in an orchard of pome fruit trees (apple, pear). The empirical model is based on 20 years of experimental data of downwind deposits of spray drift for conventional cross-flow spray applications. The model reveals the major factors affecting downwind deposits: wind speed, wind direction, air temperature and density of the tree canopy. Modelling the canopy density of the trees as a continuous function of time is an innovative approach. Canopy density is uniquely related to growth stage through the phenological BBCH index. Observed effects of the mentioned factors on deposits are discussed. Model results and measured deposits show a correlation coefficient of 87%, while covering a range of almost three orders of magnitude. The model forms the basis for risk assessment for exposure of aquatic organisms concerning all edge-of-field water bodies in the Netherlands. Implementation of drift mitigation techniques is straightforward when appropriate experimental data on reductions of downwind spray deposits is available.

Spray Deposition inside Tree Canopies from a Newly Developed Variable-Rate Air-Assisted Sprayer

Abstract. Conventional spray applications in orchards and ornamental nurseries are not target-oriented, resulting in significant waste of pesticides and contamination of the environment. To address this problem, a variable-rate air-assisted sprayer implementing laser scanning technology was developed to apply appropriate amounts of pesticides based on tree canopy characteristics including tree height, width, volume, foliage density, and occurrence. The new sprayer performance was evaluated in an apple orchard by quantifying spray deposition inside canopies at three different growth stages (leafing, half-foliage, and full-foliage) with three sprayer treatments: the new variable-rate sprayer (S 1 ), the same sprayer without the variable-rate function (S 2 ), and a conventional air-blast sprayer (S 3 ). Their spray coverage and deposits inside canopies were measured and compared with water-sensitive papers and nylon screens. The three sprayer treatments provided fairly consistent spray coverage and deposits in the spray direction (or canopy depth direction) at the leafing stage. The variations in spray coverage and deposits in the spray direction increased considerably for S 2 and S 3 at the half-foliage and full-foliage stages. S 1 produced better uniformity in spray coverage and deposits across the tree height direction than S 2 and S 3 at all growth stages. Compared to constant-rate sprayers, the new variable-rate sprayer only consumed 27% to 53% of the spray mixture while still achieving adequate spray coverage inside the canopies. In addition, the spray deposition from the new sprayer was very consistent regardless of the canopy growth stage. Therefore, the new sprayer increased spray efficiency and improved spray accuracy by greatly lowering the possibility of overspray, resulting in reduced spray costs and potential reduction of environmental pollution.

Farm‐scale dispersal of Bactericera cockerelli in potato crops measured using Bt mark‐capture techniques

AbstractNatural populations of Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), also known as tomato/potato psyllid, were marked in potato [Solanum tuberosum L. (Solanaceae)] crops using Bacillus thuringiensis Berliner (Bt) to investigate the impact of dispersal on crop infestation and management of potential insecticide resistance in New Zealand. The technique was adapted from previous studies that used conventional spray applications of Bt to mark Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), and identified marked individuals with selective microbiological assays and identification of characteristic crystal inclusions. Initially, marking rates of B. cockerelli were improved by using ultra‐low volume applications of undiluted Bt, but this result was not consistent. Several other pests and natural enemies were also marked. In mark‐capture studies, marked B. cockerelli were captured over 3 days on yellow sticky traps in small trap plots of potatoes at 60, 120, 180, 250, and 350 m from the sprayed crop. Bactericera cockerelli flight activity occurred throughout daylight hours with evidence of bimodal diurnal peaks. Significantly greater numbers of B. cockerelli were captured in downwind traps. The combined dispersal curve derived from two mark‐capture experiments estimated a mean dispersal distance for B. cockerelli of 100 m in 3 days and indicated that 10% of the population dispersed further than ca. 250 m. Over the period of a growing season, this level of dispersal suggests that B. cockerelli can disperse throughout a vegetable‐growing region, with implications for crop infestation and management of potential insecticide resistance.

DIRECT INJECTION TECHNIQUE FOR BIO-PESTICIDE SPRAY

Chemical pesticides have been used in agriculture and horticulture for several decades as a brute force method of achieving pest control. As a result, the persistence of some of these chemicals has left a long-lasting impact on the environment and non-target organisms. Pollution, pest resistance, and possible implications to cancer and diseases are a few such impacts. Modern pest control is shifting away from reliance on persistent chemical pesticides in favor of a more integrated approach to pest management. Applied biological pest control is an important component in an Integrated Pest Management (IPM) program. The main objective of the current research is reducing the organism damage due to these individual mechanisms in conventional agricultural spray application system by using the direct injection of bio-pesticide. The tequniche of biopesticied (Bacillus Thuringiensis . BT) was constructed and developed in Agriculture engineering dept. kafr El.sheikh University. The result indicate the mean values of B.T. spores for direct injection and Albuz B nozzle were 4×106, 6×107 and 8x107 at operating pressure 250 kPa, 150 kPa and 100 kPa respectively. Further more, the values of B.T. at the same operating pressure for indirect sprayer were 1×105, 4×105 and 8x105 at operating pressure 250 kPa, 150 kPa and 100 kPa respectively

A New Process for Manufacturing Straw Particleboard by Impregnating and Enzyme Treatment

However, the wheat straw surface was difficult to be penetrated by adhesive due to the wax layer existed on its surface. It is a key point that how to manufacture straw particleboard with traditional resin. This paper explored a novel method to solve this problem by pre-treating straw particles with enzyme and impregnating with resin. Different from conventional spray application, straw was impregnated with phenolic resin (PF). Part of these straws was pretreated with xylanase and lipase before impreanating to improve the bonding between adhesive and straw. The results indicated that when straw was pretreated with lipase and and then applied 10% PF by impregnating, the properties of wheat straw particleboard were optimal, bending strength was 13.81 MPa, elastic modulus was 2.67GPa, internal bond strength was 0.113MPa and 2h thickness swelling was 16.74%.

Optimization of agrochemical application in olive groves based on positioning sensor

Typically, agrochemicals are applied to olive trees uniformly within a whole orchard without regard to the spatial variability of the target tree profile. The treatment efficiency can be improved by reducing the spray losses associated with deposition on the ground and off-target drift. The goals of this study were to develop a technique to evaluate the chemical losses resulting from a spray treatment applied to Spanish olive trees and to design an automated control system to adjust the application volume based on tree structure information incorporated in a prescription map and GPS technology. The automatic control system selectively actuated individual sections of the spray boom in real-time based upon the prescribed demand in the GPS map and the current geo-position information provided by the tractor’s RTK GPS system. Test results indicated that the control system, mounted on a conventional sprayer, was able to reduce the volume of spray application on the six tree rows tested by 19% when compared to conventional spray application techniques. Results also indicated that the average application loss to the soil, for all the trees, was reduced 15.25% compared to treatment with conventional equipment. Two spray collection masts of 9.5 m height were designed and built to measure the drift produced during spray application and therefore to provide data for analysis of spray distribution at various application heights within the tree. Results show that the new control system was able to achieve the same spray distribution on the tree as the conventional sprayer while reducing the volume of chemical applied.

Variable rate dosing in precision viticulture: Use of electronic devices to improve application efficiency

Two different spray application methods were compared in three vine varieties at different crop stages. A conventional spray application with a constant volume rate per unit ground area (l ha −1) was compared with a variable rate application method designed to compensate electronically for measured variations in canopy dimensions. An air-blast sprayer with individual multi-nozzle spouts was fitted with three ultrasonic sensors and three electro valves on one side, in order to modify the emitted flow rate of the nozzles according to the variability of canopy dimensions in real time. The purpose of this prototype was to precisely apply the required amount of spray liquid and avoid over dosing. On average, a 58% saving in application volume was achieved with the variable rate method, obtaining similar or even better leaf deposits.

Control of summer fruit tortrix moth, Adoxophyes reticulana, by an experimental "attract and kill" formulation.

The summer fruit tortrix moth, Adoxophyes reticulana Hubner is a major pest of fruit crops, particularly apple and pear, in temperate regions. Pheromonal control of summer fruit tortrix moth, Adoxophyes reticulana, by an experimental “attract and kill” formulation were carried out during year 2008 at the Fruit Research Station Cluj, Romania. The experimental product formulated by the researchers of the Chemical Research Institute Raluca Ripan-Romania, contains the pheromone of the summer fruit tortrix moth (the sex pheromone is a blend 9:1 of (Z)-9-tetradecenyl acetate and (Z)-11-tetradecenyl acetate) and a synthetic piretroid insecticide (cyfluthrin) in order to be compatible with the attract and kill biotechnique. The experimental product was applied in a rate of 4000 droplets per hectare with a hand operated pump dispenser. Field trial in 2008 of the experimental product was conducted in pear orchard, organized for experimental trials. Field trial in 2008 showed that this environmental friendly strategy can compete with the conventional spray application of insecticides and can provide a good alternative for Adoxophyes reticulana control in integrated pest management and fruit growing.

Spray Deposition from Ground‐based Applications of Carbaryl to Protect Individual Trees from Bark Beetle Attack

Bark beetles (Coleoptera: Curculionidae, Scolytinae) are recognized as the most important tree mortality agent in western coniferous forests. A common method of protecting trees from bark beetle attack is to saturate the tree bole with carbaryl (1-naphthyl methylcarbamate) using a hydraulic sprayer. In this study, we evaluate the amount of carbaryl drift (ground deposition) occurring at four distances from the tree bole (7.6, 15.2, 22.9, and 38.1 m) during conventional spray applications for protecting individual lodgepole pine (Pinus contorta Dougl. ex Loud.) from mountain pine beetle (Dendroctonus ponderosae Hopkins) attack and Engelmann spruce (Picea engelmannii Parry ex Engelm.) from spruce beetle (D. rufipennis [Kirby]) attack. Mean deposition (carbaryl + alpha-naphthol) did not differ significantly among treatments (nozzle orifices) at any distance from the tree bole. Values ranged from 0.04 +/- 0.02 mg carbaryl m(-2) at 38.1 m to 13.30 +/- 2.54 mg carbaryl m(-2) at 7.6 m. Overall, distance from the tree bole significantly affected the amount of deposition. Deposition was greatest 7.6 m from the tree bole and quickly declined as distance from the tree bole increased. Approximately 97% of total spray deposition occurred within 15.2 m of the tree bole. Application efficiency (i.e., percentage of insecticide applied that is retained on trees) ranged from 80.9 to 87.2%. Based on review of the literature, this amount of drift poses little threat to adjacent aquatic environments. No-spray buffers of 7.6 m should be sufficient to protect freshwater fish, amphibians, crustaceans, bivalves, and most aquatic insects. Buffers >22.9 m appear sufficient to protect the most sensitive aquatic insects (Plecoptera).

Leaf-Waste Pellets as a Herbicide Carrier for Container-Grown Ornamental Plants

An organic herbicide carrier could help reduce misapplication and environmental pollution associated with spray application of herbicides. Pellets prepared from landscape leaves that were dried, ground, and pelletized were evaluated as a preemergence herbicide carrier for container-grown ornamental plants. Isoxaben, pendimethalin, and prodiamine at rates of 1.12, 2.25, and 2.25 kg ai/ha, respectively, with either water or landscape leaf-waste pellets as a carrier were applied to chrysanthemum ‘Lisa’, spirea ‘Neon Flash’, and wintercreeper ‘Coloratus’. Common groundsel, common purslane, and giant foxtail were seeded following herbicide application. Leaf-waste pellets as a carrier produced equivalent efficacy and phytotoxicity ratings to conventional spray application of pendimethalin and prodiamine on both chrysanthemum and wintercreeper. The leaf-waste pellets were not an effective carrier for the application of isoxaben alone. The pellets had inconsistent effects on spirea phytotoxicity and growth.

Landscape Leaf-waste Pellets as an Herbicide Carrier for Container-grown Landscape Plants

Conventional herbicide applications to container-grown landscape plants, often requires multiple spray applications of herbicides in a growing season and presents problems such as non-uniform application, leaching, run-off, environmental pollution, worker exposure and phytotoxicity to the landscape plants. The use of an organic herbicide carrier could help reduce some of the problems associated with spray applications. Landscape-leaf waste pellets were evaluated as a preemergent herbicide carrier for container-grown landscape plants. Isoxaben, prodiamine and pendimethalin were applied to Chrysanthemum × grandiflorum `Lisa', Euonymus fortunei `Coloratus' and Spiraea japonica `Neon Flash', at rates of 1.12, 2.25, and 2.25 kg·ha-1 active ingredient, respectively, with either water or landscape leaf waste pellets as a carrier. Portulaca oleracea, Senecio vulgaris, and Setaria faberi were seeded following treatment application. Visual ratings on efficacy and photoxicity to landscape plants, and shoot fresh and dry biomass were determined for both weeds and crop plants. Landscape leaf pellets served as an effective carrier for application of prodiamine and pendimethalin and combinations of these herbicides with isoxaben in controlling weeds. Leaf waste pellets as a carrier produced equivalent weed control and phytotoxicity ratings to conventional spray application of these herbicides, on both Chrysanthemum and Euonymus. The pellets did not make a consistently effective carrier for the application of isoxaben alone. Application of herbicides on leaf pellets could result in more uniform herbicide applications, minimize loss of herbicides to the environment and reduce the risk of herbicide contact with nursery workers.

The Vivostat® application system: A comparison with conventional fibrin sealant application systems

The method of applying fibrin sealants may affect their physical properties and surgical performance. In this study, the characteristics of a novel fibrin-sealant application system (Vivostat were compared with conventional fibrin sealant spray systems. Delivery rates of Vivostat were highly reproducible in both high and low delivery modes (coefficient of variation [CV] < 1.0%) Airflow rates of Vivostat were 578 ml/min (6.6% (6.5% were lower and less variable than conventional systems, which ranged from 5000 to 10000 ml/min depending on the pressure. Spray forces of Vivostat were consequently lower than other systems and the deposited fibrin films formed were of more consistent thickness. Unlike other systems, blockages with Vivostat were rare on intermittent use. The Vivostat system offers the surgeon a controlled, precise and efficient means of fibrin sealant application with potential performance advantages over conventional spray application systems.

Precision Offset Spray System for Roadway Shoulder Weed Control

A precision offset spray system was developed for use by highway maintenance departments for the control of unwanted vegetation in the graded shoulder area adjacent to roadways. The offset sprayer consisted of two fundamental elements: (1) a machine vision system; and (2) a rapid response intermittent spray system. This study showed that it is feasible to use machine vision on a moving vehicle to automatically detect the presence of green plant material and to apply herbicides exclusively to plants and not to nonplant materials (e.g., bare soil). The system substantially reduced the amount of herbicide applied to non-plant material. In system tests, there was up to a 97% reduction in applied spray mix over conventional continuous spray applications with a plant deposition rate of 57% of continuous spray systems. Implementation of this technology would allow highway maintenance departments to reduce the cost of week control and the amount of chemical herbicides released into the environment, while maintaining current levels of weed control efficacy.

Efficacy of tebufenozide applied by aircraft using only upwind atomizers to control spruce budworm (Lepidoptera: Tortricidae)

The efficacy of an aerial spray technique that used only two atomizers on the upwind wing to reduce drift was evaluated by comparing it with a conventional spray application that used two atomizers on each wing. The techniques were field tested in 1995 using double applications of tebufenozide at 70 g in 2 L ha −1 to suppress populations of spruce budworm Choristoneura fumiferana (Clem.) on balsam fir, Abies balsamea. The ‘upwind only’ technique emitted 35–69% of the flow rates (L min −1) and dosages (g AI ha −1) prescribed for and achieved by the conventional spray techniques. Nevertheless, spray deposit (drops cm −2) on kromekote cards did not differ significantly between the two application methods; but significantly more ( P < 0.05) tebufenozide was recovered from foliage after conventional sprays than after sprays with the upwind atomizers. The reduction of spruce budworm populations and protection of host trees in sprayed plots were not significantly different ( P > 0.05) between the spray treatments but both were significantly better ( P < 0.01) than the untreated controls. The use of upwind atomizers only to reduce drift, effectively suppressed spruce budworm populations when tebufenozide was used at label rates.