The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Christian Nansen - One of the best experts on this subject based on the ideXlab platform.
-
Optimizing pesticide Spray Coverage using a novel web and smartphone tool, SnapCard
Agronomy for Sustainable Development, 2015Co-Authors: Christian Nansen, J. Connor Ferguson, Lloyd Groves, Rob Emery, Nicolas Garel, John Moore, Andrew HewittAbstract:The overuse of pesticides leads to contamination of water and food. Therefore, there is a need for tools and strategies to optimize pesticide application. Here we present SnapCard, a user-friendly and freely available decision support tool for farmers and agricultural consultants, available at snapcard.agric.wa.gov.au. SnapCard allows to predict, measure, and archive pesticide Spray Coverage quantified from water-sensitive Spray cards. Variables include Spray settings such as nozzle orifice size, Sprayer speed, water carrier rate and adjuvant, and weather variables such as barometric pressure, relative humidity, temperature, and wind speed at ground level. We use separate regression models for four nozzles types. Our results showed that there are strong and positive correlations between water carrier rate and Spray Coverage for all four nozzle types. Moreover, Sprayer speed is highly negatively correlated with obtained Spray Coverage. In addition, there is no consistent effect of either nozzle type or use of a particular adjuvant, across water carrier intervals. We conclude that varying combinations of Spray settings and weather conditions caused marked ranges of Spray Coverages among the four nozzle types, thus highlighting the importance of selecting the right nozzle orifice size and type. We demonstrate that realistic scenarios of environmental conditions and Spray settings can lead to predictions of very low Spray Coverage with at least one of the four nozzle types. We discuss how the novel and freely available smartphone app, SnapCard, can be used to optimize Spray Coverage, reduce Spray drift, and minimize the risk of resistance development in target pest populations.
-
quantitative impact assessment of Spray Coverage and pest behavior on contact pesticide performance
Pest Management Science, 2012Co-Authors: Xavier Martini, Christian Nansen, Natalie KincyAbstract:BACKGROUND:Standardproceduresforevaluationofpesticideperformancedonottakeintoaccountpestbehavioralresponse or incomplete Spray Coverage. In this study, a series of laboratory experiments was conducted with two non-systemic miticides (propargite and hexythiazox) applied to cotyledon cotton plants, which were subsequently infested with spider mites. The results of these laboratory experiments are discussed through a comprehensive pest population dynamics model. RESULTS: When cotton leaves were submerged in miticide solutions, both miticides provided effective control of spider mites. In a two-choice test it was demonstrated that propargite was repellent to spider mites, but not hexythiazox. Finally, the Spray Coverage on cotton plants was varied, and, for both miticides, significantly positive relationships between Spray Coverage and spider mite mortality were shown. However, propargite required higher Spray Coverage (20%) than hexythiazox (10%) to control spider mites. A theoretical model showed that, without repellency, the pesticide performance is positively correlated with target pest mobility. If the pesticide is repellent, the probability of exposure decreases, especially for a less mobile pest. CONCLUSION: With an experimental and theoretical modeling approach, it was demonstrated how the combination of behavioral avoidance and low Spray Coverage can markedly reduce pesticide performance. c � 2012 Society of Chemical Industry
R. C. Derksen - One of the best experts on this subject based on the ideXlab platform.
-
Spray Characteristics and Wind Tunnel Evaluation of Drift Reduction Potential with Air Induction and Conventional Flat Fan Nozzle
2006 Portland Oregon July 9-12 2006, 2020Co-Authors: Huseyin Guler, R. C. Derksen, H. Erdal Ozkan, Yang Yu, Charles R. KrauseAbstract:Spray drift potential, Spray Coverage, droplet size, and Spray pattern width for various sizes of air induction and conventional flat fan nozzles with equivalent orifice areas were investigated and compared under the laboratory conditions. Droplet sizes were measured with a laser imaging system, Spray Coverage on water sensitive papers (WSP) was evaluated with a boom Sprayer at a constant travel speed in a greenhouse, and ground and airborne Spray deposits were determined in a wind tunnel at two wind velocities (2.5 and 5 m/s). Tests were also conducted to evaluate the effect of air intake holes being closed or open on Spray characteristics of air induction nozzles. With the equivalent nominal flow rate, air induction nozzles had approximately 2.1 to 2.75 times larger exit orifice areas than the conventional nozzles. With the equivalent orifice area and equal liquid flow rate, there was no significant difference in droplet size, Spray pattern width, Spray Coverage, ground Spray deposit, and airborne deposit among regular air induction nozzles, the air induction nozzles with two sealed air holes, and conventional flat fan nozzles. Spray characteristics of air induction nozzles could be achieved by conventional nozzles with the equivalent orifice size operated at the pressure below the manufacturer’s recommended pressure range.
-
Spray CHARACTERISTICS AND DRIFT REDUCTION POTENTIAL WITH AIR INDUCTION AND CONVENTIONAL FLAT-FAN NOZZLES
Transactions of the ASABE, 2020Co-Authors: Huseyin Guler, H. E. Ozkan, R. C. Derksen, Yang Yu, Charles R. KrauseAbstract:Spray drift potential, Spray Coverage, droplet size, and Spray pattern width for various sizes of air induction and conventional flat-fan nozzles with equivalent orifice areas were investigated and compared under laboratory conditions. Droplet sizes were measured with a laser imaging system; Spray Coverage on water-sensitive paper (WSP) was evaluated with a boom Sprayer at a constant travel speed in a greenhouse, and ground and airborne Spray deposits were determined in a wind tunnel at two wind velocities (2.5 and 5.0 m/s). Tests were also conducted to evaluate the effect of air-intake holes being sealed or open on Spray characteristics of air induction nozzles. With the equivalent nominal flow rate, air induction nozzles had approximately 2.1 to 2.75 times larger exit orifice areas than the conventional nozzles. With the equivalent orifice area and equal liquid flow rate, there was no significant difference in droplet size, Spray pattern width, Spray Coverage, ground Spray deposit, and airborne deposit among regular air induction nozzles, air induction nozzles with two sealed air-intake holes, and conventional flat-fan nozzles. Spray characteristics of air induction nozzles could be achieved by conventional nozzles with the equivalent orifice size operated at the reduced operating pressure.
-
Evaluation of Spraying Equipment for Effective Application of Fungicides to Control Asian Soybean Rust
2006 Portland Oregon July 9-12 2006, 2020Co-Authors: H. Erdal Ozkan, R. C. DerksenAbstract:Summary Fungicides manufactured to control soybean rust are effective; however, successful control of this disease will mostly depend on proper application methods. Spray Coverage and deposition from 10 application equipment/Spray nozzles were analysed. In general, the Spray treatments with air assistance were more effective in Spraying rust fungicides than the treatments with the conventional boom Sprayer. Spray performances from the boom Sprayer with a canopy opener were very similar to the air assisted Spray treatments, and were better than other treatments with the boom Sprayer. Twin jet, Turbo Dual pattern and hollow cone nozzles produced lower Spray performances than conventional flat fan nozzles. For treatments with the boom Sprayer, medium Spray quality provided higher Spray Coverage inside canopies than coarse and fine Spray qualities. Future research will address how much fungicide inside canopies can be sufficient to control the soybean rust disease.
-
Evaluation of various Spraying equipment for effective application of fungicides to control Asian soybean rust
Aspects of applied biology, 2020Co-Authors: H. E. Ozkan, R. C. Derksen, Huseyin Guler, C. KrauseAbstract:Fungicides manufactured to control soybean rust are effective; however, successful control of this disease will mostly depend on proper application methods. Spray Coverage and deposition from 10 application equipment/Spray nozzles were analysed. In general, the Spray treatments with air assistance were more effective in Spraying rust fungicides than the treatments with the conventional boom Sprayer. Spray performances from the boom Sprayer with a canopy opener were very similar to the air assisted Spray treatments, and were better than other treatments with the boom Sprayer. Twin jet, Turbo Dual pattern and hollow cone nozzles produced lower Spray performances than conventional flat fan nozzles. For treatments with the boom Sprayer, medium Spray quality provided higher Spray Coverage inside canopies than coarse and fine Spray qualities. Future research will address how much fungicide inside canopies can be sufficient to control the soybean rust disease.
-
Influence of application equipment on deposition of Spray droplets in wheat canopy.
Aspects of applied biology, 2020Co-Authors: H. E. Ozkan, Pierce A. Paul, R. C. DerksenAbstract:Summary Fungicides manufactured to control various diseases in wheat are effective; however, successful control of diseases will mostly depend on proper application methods. The ability to provide protection across the wheat plant is important because different infections may occur on different parts of the plant canopy depending on the pathogen. The objective of this work was to identify effective application parameters to apply adequate amount of fungicides for protection against spike and foliar diseases of wheat. Field trials were conducted in 2009, 2010 and 2011 to evaluate the effect of different nozzle types and Spray qualities on Spray Coverage at three levels within the wheat canopy: at the height of the spike, flag leaf, and 30 cm below the flag leaf. Nozzles selected for this three-year study included two single flow pattern nozzles (XR 8003 and XR11003) with respectively Medium and Fine Spray qualities, and three twin-flow pattern nozzles (TJ, TTJ, TT Duo) with Spray qualities of Fine, Medium and Coarse. Water Sensitive Paper cards placed vertically at spike level (vertical), at the height of the flag leaf (horizontal top), and 30 cm below flag leaf (horizontal middle). In all three years, the mean percent Spray Coverage on vertical, horizontal top, and horizontal middle targets varied from 5–15%, 18–35%, and 8–28%, respectively, across all five treatments. The three nozzles with double Spray patterns outperformed the two single-flow pattern nozzles in deposition on vertical targets representing wheat spike. However, single-flow pattern nozzles produced higher Coverage on middle horizontal targets than the twin-flow nozzles.
Matthew J. Grieshop - One of the best experts on this subject based on the ideXlab platform.
-
Comparison of within canopy deposition for a solid set canopy delivery system (SSCDS) and an axial–fan airblast Sprayer in a vineyard
Crop Protection, 2020Co-Authors: Rajeev Sinha, Lav R. Khot, Rakesh Ranjan, Gwen-alyn Hoheisel, Matthew J. GrieshopAbstract:Abstract Solid set canopy delivery systems (SSCDS) are novel ways of pesticide Spray applications in modern high–density orchards and vineyards. Through our prior efforts, SSCDS variants have been tested and adjusted to provide optimal system configurations for Spray application in high–density apple orchards and vineyards. This present study compared two prior optimized variants of an SSCDS comprising treatments with 1–tier and 2–tier of emitters/nozzles and an axial–fan airblast Sprayer for Spray performance in a modified vertical shoot position (VSP) vineyard. Such vineyards have the vine canes constricted under trellis wires, with the top of canes being loose and more sprawling. SSCDS 1–tier had a pair of full–circle emitters installed per vine at 76 cm above the cordon. For SSCDS 2–tier, two hollow–cone nozzles were installed per vine near the drip line at 45 cm above ground level in combination with additional emitters as in 1–tier. The Sprayate was a fluorescent tracer dissolved in water at 500 ppm. Spray deposition and Coverage were quantified in different canopy zones and on either side of leaf surfaces using mylar cards and water sensitive papers (WSPs) as samplers, respectively. The samplers were respectively analyzed using fluorometry and image processing techniques. Analysis of deposition data indicated statistically similar mean deposition for different treatments, however, uniformity of distribution was higher for the airblast Sprayer treatment. Similar and uniform deposition on the mylar cards on the adaxial and abaxial leaf surfaces was observed in all the treatments, indicating that emitters/nozzles placed within a canopy can deposit similar amounts of active ingredient as an airblast Sprayer. Contrary to the deposition data, Spray Coverage was highest for the airblast Sprayer (33.5 ± 2.8%) followed by SSCDS 1–tier (21.5 ± 2.9%) and 2–tier (19.9 ± 3.0%). Such differences could be because of the use of air-assist which was absent in SSCDS based application. In summary, SSCDS provided higher canopy deposition, however, the airblast Sprayer provided higher Spray Coverage and better Spray application uniformity. Prior biological efficacy studies in apple orchards have reported equivalent insect-pest control for SSCDS and airblast Sprayer, notwithstanding the uniformity and heterogenous Spray Coverage. Therefore, future studies are warranted to collect season long pest management data in economically viable plot sizes in a vineyard.
-
Spray Coverage and pest management efficacy of a solid set canopy delivery system in high density apples
Pest Management Science, 2019Co-Authors: Paul Owensmith, R L Perry, John C Wise, Raja Zalinda Raja Jamil, George W Sundin, Matthew J. GrieshopAbstract:BACKGROUND: Air blast Sprayers are not optimized for Spraying the short statured trees in modern apple orchards, resulting in off target drift and variable Coverage. A solid set canopy delivery system (SSCDS) consisting of a microSprayer array distributed throughout the orchard was investigated as a replacement agrochemical application method in this study. SSCDS's have the potential to optimize Coverage, rapidly Spray applications, and remove the operator and tractor from the orchard. RESULTS: Air blast and SSCDS applications were compared using water sensitive paper, bioassays, and pest damage assessments. Pest management and Coverage were compared using application volumes of 700 and 795 L ha-1 , respectively. In 2013, adaxial Coverage measurements showed no difference between the treatments, but air blast Sprayers had higher Coverage levels on the abaxial surfaces. There were no significant differences in Coverage in 2014. Bioassays using Choristoneura rosaceana fed on leaf discs treated by the SSCDS displayed 95.8% mortality in 2013 and 94.2% mortality in 2014, and air blast treated larval mortality was 95% in 2013 and 100% in 2014. Damage evaluations in both years generally showed no significant differences between the air blast plots and the SSCDS plots, but significant differences between the treated plots and untreated control. CONCLUSIONS: The prototype SSCDS was an effective pest management tool in high density apples, and offered a number of advantages over an air blast. Further engineering and research into Coverage optimization would offer producers a novel tool for foliar agrochemical applications. © 2019 Society of Chemical Industry.
H. E. Ozkan - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of various Spraying equipment for effective application of fungicides to control Asian soybean rust
Aspects of applied biology, 2020Co-Authors: H. E. Ozkan, R. C. Derksen, Huseyin Guler, C. KrauseAbstract:Fungicides manufactured to control soybean rust are effective; however, successful control of this disease will mostly depend on proper application methods. Spray Coverage and deposition from 10 application equipment/Spray nozzles were analysed. In general, the Spray treatments with air assistance were more effective in Spraying rust fungicides than the treatments with the conventional boom Sprayer. Spray performances from the boom Sprayer with a canopy opener were very similar to the air assisted Spray treatments, and were better than other treatments with the boom Sprayer. Twin jet, Turbo Dual pattern and hollow cone nozzles produced lower Spray performances than conventional flat fan nozzles. For treatments with the boom Sprayer, medium Spray quality provided higher Spray Coverage inside canopies than coarse and fine Spray qualities. Future research will address how much fungicide inside canopies can be sufficient to control the soybean rust disease.
-
Spray CHARACTERISTICS AND DRIFT REDUCTION POTENTIAL WITH AIR INDUCTION AND CONVENTIONAL FLAT-FAN NOZZLES
Transactions of the ASABE, 2020Co-Authors: Huseyin Guler, H. E. Ozkan, R. C. Derksen, Yang Yu, Charles R. KrauseAbstract:Spray drift potential, Spray Coverage, droplet size, and Spray pattern width for various sizes of air induction and conventional flat-fan nozzles with equivalent orifice areas were investigated and compared under laboratory conditions. Droplet sizes were measured with a laser imaging system; Spray Coverage on water-sensitive paper (WSP) was evaluated with a boom Sprayer at a constant travel speed in a greenhouse, and ground and airborne Spray deposits were determined in a wind tunnel at two wind velocities (2.5 and 5.0 m/s). Tests were also conducted to evaluate the effect of air-intake holes being sealed or open on Spray characteristics of air induction nozzles. With the equivalent nominal flow rate, air induction nozzles had approximately 2.1 to 2.75 times larger exit orifice areas than the conventional nozzles. With the equivalent orifice area and equal liquid flow rate, there was no significant difference in droplet size, Spray pattern width, Spray Coverage, ground Spray deposit, and airborne deposit among regular air induction nozzles, air induction nozzles with two sealed air-intake holes, and conventional flat-fan nozzles. Spray characteristics of air induction nozzles could be achieved by conventional nozzles with the equivalent orifice size operated at the reduced operating pressure.
-
Development of a Variable-Rate Sprayer with Laser Scanning Sensor to Synchronize Spray Outputs to Tree Structures
Transactions of the ASABE, 2020Co-Authors: Y. Chen, H. E. OzkanAbstract:Efficient and effective precision Spray equipment and strategies are in high demand to reduce pesticide use in tree crop production. An experimental variable-rate air-assisted Sprayer implemented with a high-speed laser scanning sensor was developed to control the Spray output of individual nozzles in real time. The Sprayer consisted of a laser scanning sensor control system and an air and liquid delivery system. Each nozzle in the delivery system, coupled with a pulse width modulated (PWM) solenoid valve, achieved variable-rate delivery based on occurrence, height, and width of the target tree and its foliage density. Other components of the sensor control system included a unique algorithm for variable-rate control that instantaneously processed measurements of the canopy surfaces. To determine system delay time, a high-speed video camera was used to record the time period between sensor detection of the canopy and nozzle activation. Spray deposition uniformity inside canopies was verified by quantifying Spray Coverage inside four ornamental nursery trees of different sizes and canopy densities at 3.2 and 6.4 km h-1 travel speeds. Test results demonstrated that differences in Spray Coverage inside the canopies of these four trees in the Spraying direction were not statistically significant, even though these trees had different structures, canopy volumes, and foliage densities. The canopy volume and foliage density measured with the algorithm developed for the laser sensor-controlled detection system exhibited little variation between the two travel speeds. Design criteria for the sensor-controlled system in the experimental Sprayer were acceptable for variable-rate application, having great potential for Spray volume and drift reduction, and thus reducing environmental impact.
-
Influence of application equipment on deposition of Spray droplets in wheat canopy.
Aspects of applied biology, 2020Co-Authors: H. E. Ozkan, Pierce A. Paul, R. C. DerksenAbstract:Summary Fungicides manufactured to control various diseases in wheat are effective; however, successful control of diseases will mostly depend on proper application methods. The ability to provide protection across the wheat plant is important because different infections may occur on different parts of the plant canopy depending on the pathogen. The objective of this work was to identify effective application parameters to apply adequate amount of fungicides for protection against spike and foliar diseases of wheat. Field trials were conducted in 2009, 2010 and 2011 to evaluate the effect of different nozzle types and Spray qualities on Spray Coverage at three levels within the wheat canopy: at the height of the spike, flag leaf, and 30 cm below the flag leaf. Nozzles selected for this three-year study included two single flow pattern nozzles (XR 8003 and XR11003) with respectively Medium and Fine Spray qualities, and three twin-flow pattern nozzles (TJ, TTJ, TT Duo) with Spray qualities of Fine, Medium and Coarse. Water Sensitive Paper cards placed vertically at spike level (vertical), at the height of the flag leaf (horizontal top), and 30 cm below flag leaf (horizontal middle). In all three years, the mean percent Spray Coverage on vertical, horizontal top, and horizontal middle targets varied from 5–15%, 18–35%, and 8–28%, respectively, across all five treatments. The three nozzles with double Spray patterns outperformed the two single-flow pattern nozzles in deposition on vertical targets representing wheat spike. However, single-flow pattern nozzles produced higher Coverage on middle horizontal targets than the twin-flow nozzles.
-
development of a canopy opener to improve Spray deposition and Coverage inside soybean canopies part 2 opener design with field experiments
Transactions of the ASABE, 2008Co-Authors: R. C. Derksen, H. E. Ozkan, Michael E Reding, C R KrauseAbstract:Conventional boom Sprayers usually are not effective in delivering droplets to inner parts of dense target canopies, such as soybeans at growth stages from R3 to R5. An experimental mechanical canopy opener was developed with the assistance of mathematical models and attached to a conventional boom Sprayer to increase Spray deposition and Coverage inside soybean canopies. The opener consisted of a 2.5 cm diameter metal pipe to push canopies forward, and a frame for connecting the pipe to the Spray boom. Field experiments were conducted to determine the amount of Spray deposition and percentage of Spray Coverage on artificial targets at the middle and lower portions of soybean canopies with three opener depths (7.5, 15, and 22.5 cm), three opener widths (15, 25, and 35 cm), and two different sizes of flat-fan nozzles. Additional field experiments were conducted to compare Spray deposition and Coverage inside soybean canopies among treatments using an air-assisted Sprayer, the conventional boom Sprayer with the opener, and the boom Sprayer with a conventional flat-fan nozzle and a dual-pattern nozzle assembly without the opener. At the time of experiments, the soybean plants were at R5 growth stage with an average height of 1.06 m. An opener width of 25 cm or larger significantly increased the Spray deposition and Coverage inside the canopies. An opener depth from 7.5 to 15 cm had better Spray Coverage than the 22.5 cm opener depth. The boom Sprayer with the opener produced no significant difference in Spray deposition and Coverage at the middle of canopies compared to the air-assisted Sprayer, but it did produce significantly lower Spray deposition and Coverage at the lower portions of canopies than the air-assisted Sprayer. With assistance from the opener to push the top of canopies, Spray deposition and Coverage on targets inside soybean canopies by the boom Sprayer was improved.
Beate Berkelmann-loehnertz - One of the best experts on this subject based on the ideXlab platform.
-
Early pathogen detection under different water status and the assessment of Spray application in vineyards through the use of thermal imagery
Precision Agriculture, 2008Co-Authors: Manfred Stoll, Hans R. Schultz, Gerhard Baecker, Beate Berkelmann-loehnertzAbstract:Remote detection using thermal imagery has potential for use in the pre-symptomatic diagnosis of abiotic stress or of early disease detection. The latter is an issue of great importance since late detection of fungus attacks or poor Spray Coverage are major factors contributing to weak disease control affecting fruit quality or reducing yield in grapes. In greenhouse experiments the effects on spatial and temporal variability of leaf temperature of grapevine ( Vitis vinifera L. cv. Riesling) leaves inoculated with a fungal pathogen ( Plasmopara viticola (Berk. & Curt. Ex de Bary) were studied in either well-irrigated or non-irrigated potted plants. Due to the high sensitivity of leaf temperature to the amount of water transpired, infra-red thermography can be used to monitor irregularities in temperature at an early stage of pathogen development. Evidence for characteristic thermal responses in grapevines was apparent well before visible symptoms appeared. Contrasting thermal effects due to the pathogen attack were found between measurements on well-irrigated and water-stressed plants. Furthermore, from a technical point of view, thermal imagery has the potential to assess the evenness of Spray Coverage within a canopy, hence optimizing pesticide application efficiency.
