Progress 12/11/08 to 12/10/13
Outputs
Progress Report Objectives (from AD-416): Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416): Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. This is a summary of the progress on this project which expired December 10, 2013 and was replaced with 3607-21620-009-00D. An experimental real-time variable-rate sprayer that implemented high frequency ultrasonic sensors and pulse width modulation solenoid valve- controlled spray nozzles was developed to adjust spray outputs automatically based on the liner canopy size. The sprayer performance consistency was tested in a field, and pest control efficacy of the sprayer was also conducted in a commercial nursery in Oregon. An intelligent, real-time, variable-rate, air-assisted sprayer that implemented a high speed laser scanner sensor and an automatic variable rate control system was developed for ornamental nurseries and fruit trees. The accuracy of the sprayer to maintain constant droplet size distributions and constant operating pressure was evaluated under both laboratory and field conditions. Air velocity profiles at different distances to the sprayer were also determined with various travel speeds and fan inlet sizes under laboratory and field conditions. Spray performance and pest control efficacy of the newly developed sprayer were evaluated and compared with conventional sprayers in a laboratory plot, three commercial nursery fields, a vineyard and an apple orchard in Ohio, Oregon and Tennessee. Spray deposition and coverage inside canopies and spray losses to the ground, in the air and around target trees were measured. Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. A traditional hydraulic sprayer with vertical booms was used to apply the spray applications. A mathematical model was developed to estimate the spray application rate required for different tree liner heights and to minimize excessive chemical use in rapidly growing tree liners. Quality spray applications with half the conventionally recommended volume of carrier and dosage of active ingredients were investigated with optimizing conventional sprayers to achieve effective pest and disease control under commercial nursery production conditions. Sprayers were optimized with properly sized nozzles and properly calibrated operating parameters. Test results were statistically analyzed and reported along with real cost benefits to producers, consumers and environment. A laboratory system was developed for evaluation of droplet evaporation and spread on plant surfaces. The system was able to control primary spray variables independently under controlled condition. Droplet spread area and evaporation on various waxy and hairy leaves of nursery plants, greenhouse crops, vegetables, field crops and weeds were investigated with different classes of conventional spray additives and new biological surfactants. Tests were also conducted to identify the best class of adjuvants and optimal concentrations to control weeds. A laboratory system was developed for evaluation of effects of primary spray factors on droplet impact, rebound and retention on leaves. The primary spray factors droplet size and velocity, physical property of sprays, leaf surface fine structure and inclination, sprayer travel speed, and chemical formulation. A portable scanning system was developed that could quickly evaluate spray deposit distribution and coverage area on deposit collectors. The accuracy of the system was verified with various nominal size spots through a stereoscopic microscope. A light weight system was developed to deliver entomopathogenic nematodes (biological pesticide) into the soil at a desired rate and depth to control soil pests in nurseries and vineyards. Significant Activities that Support Special Target Populations: The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with The Ohio State University/Ohio Agricultural Research and Development Center and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Accomplishments 01 Intelligent spraying system for nursery and orchard applications. Conventional spray application technology requires excessive amounts of pesticide use to achieve effective pest control in floral, nursery, and fruit crop productions. ARS at Wooster, Ohio, invented an automated variable-rate, air-assisted precision sprayer that minimizes human involvement to determine the amount of sprays needed for spray applications. This intelligent spraying system is able to characterize the presence, size, shape, and foliage density of target trees and applies the optimum amount of pesticide in real time. ARS scientists have built five prototype sprayers and are testing them for their pest control efficacy, reliability and durability in commercial nurseries in Ohio, Oregon and Tennessee. Field experiments have shown that the intelligent sprayer reduces the variation in spray deposition due to changes in tree structure and species, and it increases the uniformity of spray deposition on targets at different growth stages, as compared to conventional sprayers confirmed with best pest management practices. The pest control efficacies of the new sprayer are comparable to those of conventional sprayers, while the new sprayer reduces average pesticide use by 46% to 68%, for an annual average pesticide cost savings of $230 per acre. Additional tests in an apple orchard have shown that the new sprayer reduces spray loss beyond tree canopies by 40% to 87%, reduces airborne spray drift by up to 87%, and reduces spray loss on the ground by 68% and 93%. This new intelligent spraying systems has significantly advanced the technology for efficient variable-rate pesticide applications, and it offers an environmentally responsible approach to controlling pest insects and diseases.
Impacts
(N/A)
Publications
- Dong, X., Zhu, H., Yang, X. 2013. Three-dimensional imaging system for analyses of dynamic droplet impaction and deposition formation on leaves. Transactions of the ASABE. 56(5):1641-1651.
- Salyani, M., Zhu, H., Sweeb, R.D., Pai, N. 2013. Assessment of spray deposition with water-sensitive paper cards. Agricultural Engineering International: CIGR Journal. 15(2):101-111.
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Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416): Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. The spray performance of newly developed laser-sensor guided precision sprayer was tested in a laboratory plot, three commercial nursery fields and a vineyard, and was compared with the conventional spray applications. Spray deposition and coverage inside canopies were measured with nylon screens and water sensitive papers to determine the spray quality on target trees. In the laboratory plot, tests were conducted with three travel speeds, two size nozzles and six different tree species of different sizes on the same row. In the first commercial nursery field, tests were conducted with six different sizes of five tree species in two rows and three travel speeds. In the second nursery field, tests were conducted with four similar size trees of the same variety in two rows and three travel speeds to compare spray quality with a constant-rate application. In the third nursery field, tests were conducted in two plots with different widths of multi rows. One plot had four rows of sterling silver linden trees and the other plot had six rows of red oaks. In the vineyard, tests were conducted for the 10 year old red wine grape plants. Spray deposition samples were collected on the trunk, in the front, the middle and the back of three plant canopies as well as gaps between two plants. Field efficacy tests were conducted to evaluate the control of aphids and powdery mildew with our newly developed air-assisted precision sprayer in four commercial nurseries in Ohio, Oregon and Tennessee. The control efficiency was also compared between the new sprayer and conventional constant-rate sprayers. These tests will be continued for the next three years. Dispersion and evaporation of single droplets amended with four different classes of spray adjuvants on five weed surfaces were investigated. Tests were conducted under the controlled conditions to identify the best class of adjuvants and optimal concentrations to control these weeds. Evaporation rates of three types of pheromones at four ambient air temperatures and three relative humidities were measured under controlled environmental conditions. Dynamic processes of droplet impact, rebound and retention on various types of leaf surfaces were accessed with three-dimensional images. Five motion processes of droplets after they impacted on waxy and hairy leaf surfaces were observed and quantitatively analyzed with a 3-D image program. Significant Activities that Support Special Target Populations: The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with The Ohio State University/Ohio Agricultural Research and Development Center and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Accomplishments 01 Development of a precision air-assisted sprayer for tree crop production. Trees in nurseries and orchards have great variations in shapes, sizes, canopy densities and gaps between in-row trees. The variability requires future sprayers to be flexible to spray the amount of chemicals that can match tree structures. ARS researchers at Wooster, Ohio developed a variable-rate air-assisted sprayer implementing high- speed laser scanning technology to achieve these requirements. Field tests demonstrated that the new variable-rate sprayer produced significantly more consistent spray deposit and coverage inside tree canopies than the conventional sprayers, consequently resulting in less off-target loss and less pesticide use. Therefore, use of the new sprayer to deliver pest control agents will bring great benefits to growers economically and environmentally. 02 Air velocity distributions inside canopies from the precision air- assisted sprayer. Future precision air-assisted variable-rate sprayers should have a capability to control both liquid and air flows to match tree canopy structures. ARS researchers at Wooster, Ohio established a feasible and economic approach with adjusting fan inlet diameters to achieve the variable air rate function for new precision sprayers used in orchard and nursery applications. With this function, sprayers will be able to control the amount of air flow as needed to prevent crops from either over sprayed or under sprayed, and to minimize excessive off-target losses to the air and ground, resulting in preservation of air, water, and soil quality and sustainable ecosystems. 03 A system developed for investigation of dynamic droplet impaction and deposition formation on leaves. The need to elucidate droplet dynamic impaction and deposition formation on leaf surfaces to increase the biological control efficiency has been recognized for many years, but recent reports do not address this problem due to lack of scientific methodologies. ARS researchers at Wooster, Ohio developed a three- dimensional sophisticated system for analyses of dynamic droplet impaction, rebound and deposition formation on leaves. The system was able to manipulate variable droplet sizes, impact speeds and impact angles to independently test the dynamic impaction of droplets on different types of leaves with different spray solutions under controlled experimental conditions. This accomplishment would provide insights into pesticide droplet impaction and deposition formation on plant leaf surfaces to bridge the gaps of knowledge between the spray application technologies and biological control effectiveness. These underlying mechanisms are necessary to advance pesticide spray application technologies and strategies to increase effectiveness and reduce pesticide waste. 04 Tree growth with various fertilizer applications in container production. Because of vast varieties and species in nurseries, scientific guidelines are lacking for growers to improve their nutrition practices based on their specific production circumstance. Fertilizer practices with topdressing, incorporating and liquid feeding methods can cause substantial labor cost and excessive nutrient runoff loss. To provide solutions to this problem, ARS researchers at Wooster, Ohio investigated various fertilizer practices and nutrient applications for container-grown trees and established a scientific guideline for container production. Following this nutrition application strategy, growers will be able to maximize the one-year growth of container-grown trees, shorten tree production time, and save labor costs.
Impacts
(N/A)
Publications
- Gimenes, M., Zhu, H., Raetano, C., Oliveira, R. 2013. Dispersion and evaporation of droplets amended with adjuvants on soybeans. Crop Protection Journal. 44:84-90.
- Bartzanas, T., Kacira, M., Zhu, H., Karmaker, S., Tamimi, E., Katsoulas, N. , Lee, I.B., Kittas, C. 2013. Computational fluid dynamics applications to improve crop production systems. Computers and Electronics in Agriculture. 93:151-167.
- Gu, J., Zhu, H., Ding, W. 2012. Unimpeded air velocity profiles of air- assisted five-port sprayer. Transactions of the ASABE. 55(5):1659-1666.
- Guler, H., Zhu, H., Ozkan, H.E., Ling, P. 2013. Characterization of hydraulic nozzles for droplet size and spray coverage. Atomization and Sprays. 22(8):627-645.
- Zhu, H., Zondag, R., Merrick, J., Demaline, T., Jeon, H.Y., Krause, C.R., Locke, J.C. 2013. Fertilizer applications for container-grown ornamental tree production. Journal of Environmental Horticulture. 31(2):68-76.
- Chen, Y., Zhu, H., Ozkan, E. 2012. Development of variable-rate sprayer with laser scanning sensor to synchronize spray outputs to tree structures. Transactions of the ASABE. 55(3):773-781.
- Zhu, H., Wang, X., Reding, M.E., Locke, J.C. 2011. Distribution of chemical and microbial pesticides delivered through drip irrigation systems. In: Stoytcheva, M. editor. Pesticides - Formulations, Effects, Fate. Rijeka, Croatia:InTech. p 155-180.
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Progress 10/01/11 to 09/30/12
Outputs
Progress Report Objectives (from AD-416): Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416): Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. An automatic flow rate control system with a new high speed laser sensor and pulse width modulation controlled solenoid valves was designed to manipulate the output of spray nozzles simultaneously to match tree structures. Multi-channel driver and protection circuits for activating solenoid valves were developed to modulate variable-rate outputs in real time. An embedded computer (PC/104) along with a touch screen was used to process control algorithms and to fulfill communications between the operator and the control system. Laboratory tests were conducted to verify the accuracy and reliability of the flow rate control system. Air jet velocity distributions from the newly developed air assisted, five-port sprayer were measured at various locations in an open terrain and inside tree canopies. The air jet velocity was controlled by changing the sprayer fan inlet diameter and was measured with a constant temperature anemometer system coupled with hot-film sensors. Other variables for the tests were sprayer travel speed, tree canopy structure, horizontal and vertical distances from spray nozzles, and fan inlet diameter. Spray deposition and coverage inside canopies of various structures were determined with different application rates and air jet velocities for the development of new variable-rate air-assisted sprayers. Field efficacy tests were conducted to evaluate the control of aphids and powdery mildew by use of a newly developed ultrasonic sensor controlled variable-rate sprayer in a commercial nursery in Oregon. The control efficiency was also compared between the new variable-rate sprayer and a conventional constant-rate sprayer. Biological surfactants were investigated to improve droplet behaviors on leaf surfaces. Droplet spread area and evaporation rate on various waxy and hairy leaf surfaces were measured with different concentrations of the biological surfactants, and were compared with conventional surfactants. Dispersion and evaporation of single droplets amended with four different classes of spray adjuvants on four soybean plant surfaces were investigated. Tests were conducted under the controlled conditions to identify the best class of adjuvants and optimal concentrations to improve pesticide spray application efficiency for soybeans. A system was developed to determine pheromone evaporation rates under controlled environmental conditions. The system was able to control ambient temperature and relative humidity separately. Weight changes of three commonly used pheromones were measured at various temperatures and relative humidities. Each sample was tested for seven days with the sampling rate of 15 minutes per weight measurement. A system was developed to investigate droplet dynamic impact and retention on leaf surfaces. The system consisted of a uniform droplet generator, two high speed digital video cameras, a constant speed track, a leaf holder, and a cool light source. Dynamics of droplet impact, rebound and retention on two waxy leaves were determined with different droplet diameters, droplet discharge speeds, nozzle travel speeds, and leaf surface orientations. Significant Activities that Support Special Target Populations: The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with The Ohio State University/Ohio Agricultural Research and Development Center and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Accomplishments 01 Air velocity profiles of air-assisted five-port sprayer. Although curren air-assisted sprayers provide improved spray penetration and deposition uniformity, they are not able to adjust both liquid and air flow rates a needed and thus spray losses are still considerable. Future variable-rat sprayers should have a capability to control both liquid and air flows t match tree canopy structures. This study investigated the effect of fan inlet diameters on characterization of air velocity profiles from an air assisted five-port sprayer, in an effort to form a basis for the development of an automatic device to control the air flow rate for the future variable-rate sprayers. Test results demonstrated that the air velocities and airflow pressures for a particular fan inlet diameter wer relatively uniform, confirming the capability of the sprayer to discharg uniform spray profiles for carrying droplets. Consequently, this study established a feasible and economic approach for the new precision sprayers to achieve the variable air rate function in orchard and nurser applications. With this function, sprayers will be able to control the amount of air flow as needed to prevent crops from either over sprayed o under sprayed, and to minimize excessive off-target losses to the air an ground from droplets passing through the canopy. 02 Development of variable-rate hydraulic boom sprayer for nursery liner applications. Pesticide application rates for ornamental nursery fields are determined by the largest tree group. Thus, over-applications of pesticides in ornamental nurseries are frequently observed due to tree size variations and no automated rate adjustment function in field sprayers. An experimental sprayer, which autonomously detects nursery tr canopy and its size and adjusts spray output in real time, was developed to address the pesticide over-application in ornamental nursery fields. The sprayer was tested to determine sprayer�s accuracy in spray timing. addition, reliability in detecting canopy and ground speed effects in spray deposit and coverage were investigated in a laboratory test field. The results from this study demonstrated the newly developed sprayer was able to deliver uniform spray deposition and coverage for nursery liner applications despite variations in liner canopy size and sprayer travel speed. The new variable-rate sprayer would be beneficial to growers in terms of reducing pesticide cost and off-target loss with the capability of adjusting spray outputs automatically to match tree sizes. 03 Evaluation of a newly developed variable-rate sprayer for nursery liner applications. Properly applying chemicals to nursery liner crops is essential to protect them from biological harm and maintain their qualit However, few application technologies have been specifically designed fo these crops and nursery growers have to use either orchard or modified ground sprayers for their chemical applications. An experimental variabl rate sprayer was designed and tested for liner applications in a laboratory plot. Its spray deposit, coverage, and droplet density insid canopies of various nursery liner varieties was compared with constant- rate applications. The variable-rate application had lower variation in spray deposits inside tree canopies than constant-rate applications. Moreover, spray volume savings of the variable-rate sprayer were up to 7 compared to the conventional application of the constant rate that was normally recommended for liner spray applications. Therefore, the newly developed variable-rate sprayer would bring great reductions in pesticid use and safeguard the environment for the nursery liner production. 04 Development of variable-rate air-assisted sprayer. In nurseries and orchards, foliar pesticide application is the most effective method to protect crops from pest damages and prevent yield losses. However, due t a great diversity in canopy structure and foliage density, conventional spray systems and methodologies are inefficient and often cause excessiv pesticide usage. This research developed an experimental air-assisted variable-rate spraying system with integration of high-speed laser scanning technology to characterize the occurrence, height, width and foliage density of tree canopies and then control spray outputs to match targeted tree structures. The accuracy of the variable-rate sprayer to deliver chemicals to targets was validated by examining the uniformity o spray coverage inside different ornamental trees at different travel speeds. Test results demonstrated that the sprayer had capabilities to achieve variable spray rates for different canopy volumes and foliage densities with acceptable variations in spray coverage inside tree canopies. Now, it is feasible to have a new generation of precision sprayers for nursery and orchard growers to prevent excessive pesticide use, and thus reduce production costs, worker exposure to pesticide risk and adverse environmental contamination. 05 Dispersion and evaporation of droplets amended with adjuvants on soybean Soybeans are often susceptible to insect infestations and to diseases th cause significant yield losses. Protective pesticide spray applications soybeans can increase yield and quality, but they also increase producti costs which can be ameliorated with less spray mixtures and minimized of target loss. The effects of four different groups of adjuvants at variou concentrations on dispersion and evaporation of single droplets were investigated under controlled conditions. This systematic investigation precisely demonstrated that adjuvant-amended foliar sprays increased the coverage area on soybean plants by over 400%, which is a fourfold reduction in spray volume. The use of adjuvants also improved the homogeneity of sprayed pesticides. These findings provide convincing evidence to growers that they can potentially reduce significant amounts of spray mixtures by using adjuvants to increase droplet dispersion on soybean plants, resulting in reduced soybean production cost and also reduced environmental contamination.
Impacts
(N/A)
Publications
- Jeon, H., Zhu, H. 2012. Development of variable-rate sprayer for nursery liner applications. Transactions of the ASABE. 55(1):303-312.
- Jeon, H., Zhu, H., Derksen, R.C., Ozkan, E., Krause, C.R. 2012. Performance evaluation of a newly developed variable rate sprayer for nursery liner applications. Transactions of the ASABE. 54(6):1997-2007.
- Gu, J., Zhu, H., Ding, W., Jeon, H. 2011. Droplet size distributions of adjuvant-amended sprays from an air-assisted five-port PWM nozzle. Atomization and Sprays. 21(3):263-274.
- Zhu, H., Zondag, R.H., Krause, C.R., Merrick, J., Daley, J. 2011. Reduced use of pesticides for effective controls of arthropod pests and plant diseases. Journal of Environmental Horticulture. 29(3):143-151.
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Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416) Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. An experimental real-time variable-rate sprayer that implemented high frequency ultrasonic sensors and pulse width modulation solenoid valve- controlled spray nozzles was developed to adjust spray outputs automatically based on the liner canopy size. The accuracy of the sprayer in triggering spray against detected targets was evaluated by use of a high-speed camera. A laboratory field consisting of six different sized tree species was used to test the sprayer performance consistency. Influences of liner canopy size and sprayer travel speed on uniformity of spray deposition and coverage inside nursery liner canopies were analyzed. An experimental, real-time, variable-rate, air-assisted sprayer that implemented a high speed laser scanner sensor and portable computer was developed for ornamental nurseries and fruit trees. The accuracy of the sprayer to maintain constant droplet size distributions and constant operating pressure was evaluated under both laboratory and field conditions. Air velocity profiles at different distances to the sprayer were also determined with various travel speeds and fan inlet sizes under laboratory and field conditions. Droplet spread area and evaporation on various waxy leaves were investigated with different classes of spray additives. Tests were conducted under the controlled conditions. The magnitude of the influence of individual variables on droplet behaviors was determined. Impact, rebound and retention of mono-size droplets on various surface characteristics were investigated with high speed video cameras under laboratory-controlled conditions. Quality spray applications with half the conventionally recommended volume of carrier and dosage of active ingredients were investigated with existing spray equipment to achieve effective pest and disease control under commercial nursery production conditions. Investigations included six different air-assisted sprayers in two tests and State inspector surveys for the control of arthropod pests and plant diseases. Sprayers were optimized with properly sized nozzles and properly calibrated operating parameters. Test results were statistically analyzed and reported along with real cost benefits to producers, consumers and environment. Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on two and three-year old red maple liners. A traditional hydraulic sprayer with vertical booms was used to apply the spray applications. A mathematical model was developed to estimate the spray application rate required for different tree liner heights and to minimize excessive chemical use in rapidly growing tree liners. A portable scanning system was developed that could quickly evaluate spray deposit distribution and coverage area on deposit collectors. The system is integrated with a handheld business card scanner, deposit collectors, a laptop computer, and original software package entitled �DepositScan�. The accuracy of the system was verified with various nominal size spots through a stereoscopic microscope. Significant Activities that Support Special Target Populations The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with The Ohio State University/Ohio Agricultural Research and Development Center and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Accomplishments 01 Optimal spray application rates for ornamental nursery liner production. Production of liners is an essential process for providing abundant bareroot stocks for the ornamental nursery industry to beautify our environment. Liners are one to three-year old young trees grown in nurseries prior to being transplanted to fields or containers where they continue growing into larger, market-ready shade trees. They are normall planted densely and grow rapidly during a growing season, which can aggravate the severity and incidence of insect infestations and diseases In response to an onset of pest infestations and diseases, spray applicators must make decisions within a very narrow time window on how much pesticide and spray volume is needed for economical control. ARS researchers at Wooster, Ohio quantified the amount of spray deposition a coverage inside ornamental nursery liner canopies from an over-the-row frame vertical boom sprayer, determined its optimal application rates, a established a spray rate model for different size liners. Growers are no using the research findings to increase spray application efficiency, minimize potential environmental contamination due to over application o pesticides, maximize the effectiveness of pest management strategies, an achieve real cost savings for their liner production. 02 Capability of patch antennas in a portable radar system to track insects Every year insect pests cause substantial economic losses to agricultura and forest crops. To develop more effective pest control measures and limit their spread, data on the dispersal and behavioral patterns of the insects are needed to help develop control and management strategies. AR researchers at Wooster, Ohio and The Ohio State University researchers investigated the performance of their newly developed entomological rada tracking system as a potential tool to study insect behavior, migration, and population. The system was light and had low power consumption. This technology has a great potential to be used for tracking agricultural an forest insects and even animals. 03 Comprehensive application technology and strategy to reduce pesticide us Pesticide applications are critical to ensure healthy, unblemished ornamental nursery plants. However, conventional spray application practices only suggest for the modification of carrier volume for preparations of spray mixtures, but not the amount of active ingredients per unit area. ARS researchers at Wooster, Ohio have tested their strategies of using half-rate applications of pesticides and judicious adjustments of air-assisted sprayers in commercial nurseries. They demonstrated that growers could use their existing spray equipment to reduce pesticide and water use by 50% with properly changing spray nozzl at no extra cost and still achieve the effective pest and disease contro This equals to doubling the pesticide application efficiency with reduce pesticide costs, reduced health risk to applicators, and diminished adverse impact to the environment. Other benefits accrued with this approach included increased operational efficiency (the area sprayed is doubled, the frequency and travel time required for the tank refilling times are reduced) and reduced costs for energy consumption and for new equipment, as well as reduced risk of pesticide exposure of workers. By using the half-rate practice, growers reported savings of over $200-$500 per acre. 04 Development of variable-rate sprayer for nursery liner applications. Growing liners is a specialized business for some ornamental nurseries. These liners are young trees that are grown in densely planted rows for two to three years and then sold to other nurseries who then transplant and grow them to market size. Because of their rapid growth in a confine space, pesticide applications are needed to protect them from insect pes and diseases. However, variations in tree size and varieties invariably confound spray applications and over-applications of pesticide are alway possible. ARS researchers at Wooster, Ohio developed an experimental intelligent sprayer using ultrasonic sensors and pulse-width modulated spray nozzles to deliver real-time variable-rate sprays to liners based their canopy size. The newly developed sprayer could achieve uniform spr deposition and coverage for nursery liner applications despite variation in liner canopy size and sprayer travel speed. 05 Droplet evaporation and spread on waxy and hairy leaves. Pesticide spra application efficiency is often improved with enhanced droplet adhesion leaf target surfaces which is achieved by the addition of adjuvants to spray mixtures. Use of pesticide will be reduced resulting in effective pest control if the active ingredients in droplets uniformly spread out and remain on the target area. ARS researchers at Wooster, Ohio and The Ohio State University researchers determined the fate of water droplets amended with different classes of adjuvants at various concentrations on plant leaves. They clearly demonstrated the fact that the use of adjuvan could greatly improve the homogeneity of sprayed pesticides to increase the coverage area on waxy and hairy leaves, thereby offering possibiliti of reduced pesticide usage, and leading to economic benefit to the farme and reduced risk of contamination of the environment by pesticides. Growers, extension educators and chemical companies in the U.S. and othe countries are using the research findings to increase pesticide application efficiency.
Impacts
(N/A)
Publications
- Jeon, H., Zhu, H., Derksen, R.C., Ozkan, H., Krause, C.R. 2011. Evaluation of ultrasonic sensors for the variable rate tree liner sprayer development. Computers and Electronics in Agriculture. 75(1):213-221. DOI:10.10161j. compag.2010.11.007.
- Xu, L., Zhu, H., Ozkan, E., Bagley, B., Krause, C.R. 2011. Droplet evaporation and spread on waxy and hairy leaves associated with type and concentration of adjuvants. Pest Management Science. 67:842-851. DOI: 10. 1002/ps.2122.
- Zhu, H., Salyani, M., Fox, R.D. 2011. A portable scanning system for evaluation of spray deposit distribution. Computers and Electronics in Agriculture. 76(1):38-43.
- Zhu, H., Psychoudakis, D., Brazee, R.D., Thistle, H.W., Volakis, J.L. 2011. Capability of patch antennas in a portable harmonic radar system to track insects. Transactions of the ASABE. 54(1):355-362.
- Zhu, H., Grewal, P.S., Reding, M.E. 2011. Development of a desiccated cadaver delivery system to apply entomopathogenic nematodes for control of soil pests. Applied Engineering in Agriculture. 27(3):317-324.
- Zhu, H., Altland, J.E., Derksen, R.C., Krause, C.R. 2011. Optimal spray application rates for ornamental nursery liner production. HortTechnology. 21(3):367-375.
- Jeon, H., Tian, L.F., Zhu, H. 2011. Robust crop and weed segmentation under uncontrolled outdoor illumination. Sensors. 11(6)6270-6283.
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416) Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. Residue patterns and evaporation time of single droplets that incorporated four classes of adjuvants on five different waxy plants were investigated under the controlled conditions. Droplets were generated with a single-droplet generator and deposited on target leaves placed in an environmentally-controlled chamber at 60% relative humidity and 25 �C ambient temperature. Droplets with oil-based adjuvants had more uniform residual distribution in the deposition patterns than droplets with the surfactant adjuvant. Evaporation and deposit pattern formation of single droplets deposited at various locations on waxy leaves were investigated under controlled conditions. The leaf locations included the interveinal area, midrib and secondary vein on both adaxial and abaxial surfaces. Tests were conducted with two sizes of droplets containing water and a nonionic surfactant. A light weight system was developed to deliver infected desiccated cadavers carrying entomopathogenic nematodes into the soil. The system mainly consists of a metering unit, an air pressure source, a cadaver scraper, a custom-designed cadaver container, tension adjustment devices, double disk soil opener, a discharge tube, a packer wheel, and a press/drive wheel. Laboratory and field tests were conducted to verify the system delivery accuracy. Reduced rate applications of chemicals for control of insect and disease in nursery production were investigated in nurseries in Ohio and Kentucky. Leaf samples were collected and assessed for insect and disease damage for the half-rate and full-rate chemical trials. A portable scanning system was developed that could quickly evaluate spray deposit distribution and coverage area on deposit collectors such as water sensitive paper. After scanning the collectors, individual droplet sizes, their distributions, total droplet number, and percentage of area coverage are displayed on the computer screen and saved in a spreadsheet. A series of tests to evaluate durability and detection stability of an ultrasonic sensor was carried out under cold weather exposure, wind, dust, travel speed, air temperature and spray cloud conditions. A strategy to configure the sensor with spray nozzles was developed to reduce root mean square errors. A real-time variable-rate experimental sprayer was developed to reduce pesticide usage by coinciding spray outputs with canopy sizes. Srayer performances including accuracy of spray timing and spray modulation as well as percent spray coverage inside tree canopies were evaluated under both laboratory and field conditions. A precision air-assisted sprayer implementing an automatic variable rate control system is in the process of development for ornamental nurseries and fruit trees. A high speed laser scanner was investigated to detect gaps between trees, and measure tree characteristics. Interfaced program between laser and computer was developed to determine the tree size and shape. Laboratory and field tests were conducted to verify the accuracy of spray controller timing and modulation. A laboratory system was developed for evaluation of droplet impact, rebound and retention on leaves. Significant Activities that Support Special Target Populations The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with OSU/OARDC and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Accomplishments 01 Adjuvant effects on behaviors of pesticide droplets on waxy leaves. Pesticide applications have ensured a bountiful supply of high quality crops, but the public has concerned about its increased use and its effects on worker safety, environmental contamination, and adverse impac on a vulnerable ecosystems. Residue patterns of single droplets and thei evaporation time in four classes of adjuvants on five different waxy plants were determined under the controlled conditions. Results of this study demonstrated that the use of an appropriate class of adjuvants significantly improved droplet deposition on waxy leaves and the effectiveness of pesticides, and is critical to the process to reduce of target losses. 02 Behavior of droplets amended with or without surfactants at different sites of waxy leaf surfaces. Although numerous studies have been conduct to accurately deliver chemical droplets on targets, the behavior of chemical droplets after their deposition on leaf surfaces largely remain unknown. Our studies under controlled conditions on the rate of evaporation and residue formation from single droplets amended with or without surfactants and depositied at various locations on waxy leaves provided answers to this challenging question. This study demonstrated that the ratio between the coverage area and the amount of spray require at different sites of waxy leaves was increased by the use of surfactant and offered the possibilities of reduced spray application rates and increased application efficiency. 03 Desiccated cadaver delivery system for application of entomopathogenic nematodes to control soil pests. Root-feeding larvae are important economical pests of crops and require control measures. However, the use of conventional pesticides has raised concerns over potential contamination to the environment. Consequently, biological control agent which are considered safer and offer environmentally-friendly advantages have been promoted as an alternative approach. Entomopathogenic nematode when harbored within desiccated cadavers are more capable as a control measure of root-feeding larvae. In this study, a crop seed planter was modified to determine whether irregular-shaped, fragile and nematode- infected desiccated cadavers could be effectively delivered into the soi at a desired rate and depth as the seed planter traveled continuously along a row. Laboratory and field tests demonstrated that, although feasible, to improve accuracy of the seed planter, metering plates must specifically designed for this system to discharge desiccated cadavers a different rates. 04 Optimization of technologies for pesticide application rates in nursery production. Traditional settings of air-assisted sprayers for nursery applications often result in excessive spray deposition inside tree canopies and exacerbate off target losses. Since 2005, we have annually tested our strategies of using half-rate applications of pesticides and judicious adjustments of air-assisted sprayers in commercial nurseries. Adaptations by nursery growers of the half-rate technology have resulted in overall reduction in pesticide usage. By using the half-rate technolo growers not only reduced the use of pesticides, but also safeguarded th environment and reported savings of over $200-$500 per acre. 05 A handy helper scanning system to quickly evaluate spray deposition. Inaccurate pesticide applications on target areas cause serious spray drift and off-target loss problems, and result in excessive use of pesticides, compromise food safety, contaminate the environment and are hazard to workers. Prevention of over- or under-spray applications on intended targets requires a system that can rapidly measure spray covera and provide spray quality feedback information. �DepositScan�, a portabl scanning system, was developed that quickly evaluated spray deposition a coverage on deposit collectors. The software for DepositScan is availabl to the public without charge, and can be downloaded from our website. DepositScan is a tool for farmers, extension educators, researchers and manufacturers to increase pesticide delivery accuracy, minimize off-targ loss, and improve pesticide spray application efficiency and efficacy. 06 Detection of nursery liner canopies with ultrasonic sensors. Ornamental nursery liners (or seedlings) grow quickly during a growing season. The limited capabilities of conventional sprayers to compensate for the rapi growth of liners with the proper amount of sprays are responsible for mu of the inaccurate pesticide applications. Traditional ultrasonic sensors coupled with variable-rate sprayers cannot evaluate small tree liners. Thus, sensors in advanced sprayers that automatically adjust spray outpu based on canopy sizes are needed. Our newly designed detecting system implementing fast detection ultrasonic sensors for high travel speeds satisfied the requirements for durability and measurement stability unde field conditions. This new generation of detecting technologies has made advanced variable-rate sprayers for tree liner application a reality. 07 A real-time variable-rate sprayer for nursery liner applications. Pesticide applications on ornamental nursery tree liners with convention sprayers to control pests and diseases are excessive. A real-time, variable-rate experimental sprayer where spray outputs coincided with canopy sizes was developed to reduce pesticide usage. In laboratory test the experimental sprayer reduced the average application rates by 59 to 75%, and demonstrated that pesticide usage could be greatly reduced when variable-rate spray applications are determined by canopy sizes and occurrences. The potential use of the sprayer could be extended to other fruit crops including vineyards.
Impacts
(N/A)
Publications
- Yu, Y., Zhu, H., Frantz, J., Reding, M.E., Chan, K.C. 2009. Evaporation and Coverage Area of Pesticide Droplets on Hairy and Waxy Leaves. Biosystems Engineering. 104:324-334.
- Yu, Y., Zhu, H., Derksen, R.C., Krause, C.R. 2009. Evaporation and Deposition Coverage Area of Droplets Containing Insecticides and Spray Additives on Hydrophilic, Hydrophobic and Crabapple Leaf Surfaces. Transactions of the ASABE. 52(1):39-49.
- Xu, L., Zhu, H., Ozkan, E., Thisle, H. 2010. Evaporation Rate and Development of Wetted Area of Water Droplets with and without Surfactant at Different Locations on Waxy Leaf Surfaces. Biosystems Engineering. 106: 58-67.
- Xu, L., Zhu, H., Ozkan, E., Bagley, B., Derksen, R.C., Krause, C.R. 2010. Adjuvant Effects on Evaporation Rates and Wetted Area of Droplets on Waxy Leaves. Transactions of the ASABE. 53(1): 13-20.
- Zhu, H., Yu, Y., Ozkan, H. 2010. Influence of Spray Formulation and Leaf Surface Structure on Droplet Evaporation and Wetted Area. Aspects of Applied Biology. 99:333-340.
- Wang, X., Zhu, H., Reding, M.E., Locke, J.C., Leland, J.E., Derksen, R.C., Spongberg, A.L., Krause, C.R. 2009. Delivery of Chemical and Microbial Pesticides from Drip Irrigation Emitters. Applied Engineering in Agriculture. 25(6):883-893.
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) Develop precision sprayers that can continuously match canopy characteristics to deliver agrichemicals and bio-products accurately to nursery and fruit crops. Identify and characterize factors that have the greatest impact on foliar pesticide spray application efficiency: determine how water droplets amended with spray additives, relative humidity and the morphological surfaces of leaves affect the droplet evaporation time, spread factor and residual pattern on leaves; determine how the droplet size and velocity, spray formulation, and morphological surface of leaves affect spray impact, retention and coverage. Identify and evaluate agrichemicals and bio-products that can be precisely delivered through drip irrigation systems. Approach (from AD-416) Precision sprayers with wide range controllable flow rate, multi-jet nozzles will be developed to reduce the amount of pesticides required by matching spray characteristics to specific types of ornamental nursery and fruit trees. Fast response, high resolution, non-contact sensors will be used to detect the plant size, shape, density and position. Based on the plant structure data from the sensors, air velocity, spray application rate and number of jets will be determined to control the spray outputs as needed. All these operations will occur as the sprayer moves past the plant, providing uniform spray coverage with minimum off- target loss. Evaporation time, spread factor and chemical residual pattern area of individual droplets containing spray additives on leaves will be measured via sequential imaging under controlled conditions. Droplets will be placed inside an environmental-controlled chamber under a stereomicroscope and a high definition digital camera. A large database will then be developed including droplet evaporation time, and deposit pattern area on leaves with different surface characteristics, droplet sizes, chemical formulation components, and relative humidity conditions. A laboratory system will be developed to determine dynamic effects of spray characteristics on spray impact, retention and coverage on fine surface structure plants. All individual pesticide spray application variables will be controlled under laboratory conditions. The system contains a turntable, a mono-disperse droplet generator and uniform air carrier to deliver droplets onto leaves or selected polymer targets with defined surface properties. Droplet impact and rebound velocity will be measured with a particle/droplet laser image analysis system. A cold field emission scanning electron microscope (CFESEM) and a variable pressure scanning electron microscope will be used to determine leaf surface fine structure, droplet coverage area, residue deposit form and composition, and distribution of active ingredients on leaf target surfaces. Variables will be droplet size, droplet velocity, travel speed, type of liquid formulation, physical properties and concentration of spray additives, leaf orientation, leaf deformation, leaf wax and leaf roughness. Relationships among the spray droplet retention, distribution and coverage area on leaf surfaces with the variables will be determined and documented in a large database as a guideline to choose the optimum operational parameters. An engineering testing system for delivering agrochemicals and bio- pesticides through drip irrigation will be developed. All individual delivery variables will be controlled in the system. The distribution uniformity of agrochemicals and bio-pesticides with different physical properties and particle sizes throughout drip lines and in the soilless substrates and soil will be investigated. Tests will also include determination of emitter sizes and amounts of water needed to diffuse bio- pesticides in the soilless substrate in various size containers. A new injection unit will be developed to precisely deliver suspendable bio- pesticides through drip irrigation. Significant Activities that Support Special Target Populations A precision air-assisted sprayer implementing an automatic variable rate control system is in the process of development for fruit trees and ornamental nurseries. A high speed laser scanner was investigated to detect gaps between trees, and measure tree characteristics. Interfaced program between laser and computer was developed to determine the tree size and shape. Ultrasonic sensors were evaluated for the development of variable-rate sprayers to apply pest control agents for liner nurseries. Durability and detection stability of the sensors were tested under the conditions of winter storage and field spray application. A laboratory system was developed for evaluation of droplet evaporation and residual pattern on leaves. Experiments were conducted under controlled conditions to investigate effects of droplet size, relative humidity, and physical property of sprays on evaporation and on the deposition coverage of single droplets on waxy and hairy leaf surfaces. The sprays included different combinations of water, a nonionic colloidal polymer drift retardant, a nonionic surfactant, insecticides and fungicides. Reduced rate applications of chemicals for control of insect and disease in nursery production were investigated in nurseries in Ohio and Kentucky. Leaf samples were collected and assessed for insect and disease damage for the half-rate and full-rate chemical trials. A portable scanning system, �DepositScan,� was developed to quickly evaluate the deposition quality of pesticide spray applications. In operation, the system first scans samples with a handheld business card scanner, and then reports individual droplet sizes, their distribution, total numbers, and percentage of coverage areas. The analysis of a spray deposition sample is completed in less than 30 seconds even under field conditions. The software is available to the public without charge, and can be downloaded from the website (http://www.ars.usda. gov/mwa/wooster/atru/depositscan). Significant Activities that Support Special Target Populations The floral and nursery grower industry needs timely weather data to aid decision making in crop management and protection. This information also benefits small farms and nurseries with less than $250,000 annual gross receipts. Research weather stations have been developed and upgraded cooperatively with OSU/OARDC and commercial nurseries in northern Ohio. Web pages have been developed to report charts on wind speed and azimuth, solar radiation, atmospheric temperature and relative humidity, precipitation, leaf wetness, barometric pressure, soil temperatures, soil moisture contents at depths from 10 to 100 cm below the soil surface, and interrelationships among variables related to leaf wetness. In addition to application technology research, data and summaries are available in real time to the grower industry via web sites to aid in crop management and protection decisions and irrigation scheduling. Technology Transfer Number of Web Sites managed: 1 Number of Other Technology Transfer: 2
Impacts
(N/A)
Publications
- Yu, Y., Zhu, H., Ozkan, H.E. 2008. Evaporation of Pesticide Droplets under Various Relative Humidity Conditions. Journal of ASTM International. 6(1) :1-8.
- Zhu, H., Brazee, R.D., Fox, R.D., Derksen, R.C., Ozkan, H.E. 2008. Development of a Canopy Opener to Improve Spray Deposition and Coverage Inside Soybean Canopies -- Part 1: Mathematical Models to Assist Opener Development. Transactions of the ASABE. 51(6):1905-1912.
- Zhu, H., Derksen, R.C., Ozkan, H.E., Reding, M.E., Krause, C.R. 2008. 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. 51(6):1913-1921.
- Zhu, H. 2009. DepositScan, a Scanning Program to Measure Spray Deposition Distributions. Software and User Manual Public Release. Available: http://www.ars.usda.gov/mwa/wooster/atru/depositscan.
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