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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Research Project #425625

Research Project: Improved Pest Control Application Technologies for Sustainable Crop Protection

Location: Application Technology Research

2017 Annual Report


Objectives
Objective 1: Establish comprehensive ground-based strategies to increase foliar retention of pesticide spray for traditional and specialty crops produced in greenhouses and the field. Sub-objective 1.1: Determine the influence of spray parameters including droplet size, formulation physical properties, ambient air conditions, and plant surface morphology on the droplet behavior, evaporation, absorption, and residual pattern on plant surfaces. Sub-objective 1.2: Determine the influence of droplet size and velocity, travel speed, spray formulation physical properties, crop characteristics, leaf surface morphology, and leaf surface orientation on spray droplet dynamic impact, retention, rebound and coverage. Objective 2: Develop intelligent-decision spraying systems to increase spray application efficiency and reduce off-target losses. Sub-objective 2.1: Develop advanced sensor-based intelligent decision systems that can be adapted for different types of sprayers. Sub-objective 2.2: Investigate spray deposition uniformity, off-target losses and pesticide savings with intelligent-decision controlled sprayers. Sub-objective 2.3: Develop drift reduction technologies (DRT) with intelligent decision systems to aid in reducing off-target losses and enabling development of sustainable production programs. Objective 3: Develop ground-based methods for improving delivery of weed management materials to nursery containerized production systems. Sub-objective 3.1: Optimize application factors such as droplet size, spray volume and irrigation volume to improve delivery efficiency of herbicides through a nursery crop canopy to the substrate surface. Sub-objective 3.2: Determine the influence of delivery and plant parameters such as air-assistance, travel speed, irrigation volume, and canopy structure on deposition of granular materials on container substrates. Objective 4: Develop alternative delivery methods for agrochemicals and bio-products. Sub-objective 4.1: Develop mechanical delivery devices to apply entomopathogenic nematodes. Sub-objective 4.2: Develop methods and strategies for efficiently applying pheromones.


Approach
This project envisions that research on intelligent spray technologies, efficient applications of bio-products as alternative pesticides, and coordinated strategies can enhance pesticide application efficiency for efficacious and affordable control of insects, diseases and weeds. The research will focus on delivery systems in conjunction with spray droplet transport, fate of spray droplets upon target impact, epidemiology of pests and pathogens, pesticide formulation, and microclimatic conditions. Selective approaches to achieve the objectives will be to: (1) establish comprehensive ground-based strategies to increase pesticide retention on specialty and traditional crops in greenhouse and field environments; determine the influence of spray parameters such as droplet size, formulation physical properties, ambient air conditions, and plant surface morphology on the droplet impaction, rebound, retention, spread, evaporation, absorption, and residual pattern on plant surfaces under the conditions that individual parameters can be controlled separately; (2) innovate advanced intelligent-decision spraying systems to increase spray application efficiency; investigate spray deposition uniformity, spray drift, off-target losses and pesticide savings for ornamental nurseries, orchards and other specialty crops with intelligent-decision controlled sprayers; develop drift reduction technologies with intelligent decision systems to aid in enabling development of sustainable production programs; (3) develop methodologies to improve herbicide applications for containerized nursery production systems; optimize application factors such as droplet size, spray volume and irrigation volume to improve delivery efficiency of herbicides through a nursery crop canopy to the substrate surface; determine the influence of delivery and plant parameters such as air-assistance, travel speed, irrigation volume, and canopy structure on deposition of granular herbicides on container substrates; (4) develop mechanical delivery devices to apply new agrochemicals and bio-products for pest control; discover innovative techniques for accurate delivery of entomopathogenic nematode infected insect larvae to effectively control soil pests; develop methods and strategies for efficiently applying pheromones by designing new dispensers with controlled evaporation rates.


Progress Report
A universal intelligent spray control system was developed for field tests. The control system was retrofitted on growers’ existing sprayers in two ornamental nurseries in Ohio and one peach orchard in South Carolina. With the retrofit, growers’ sprayers were upgraded to perform intelligent functions controlling spray outputs to match canopy presence, size and leaf density. Intelligent sprayer prototypes were evaluated for their efficacy, efficiency and reliability in nurseries, vineyards and fruit farms in Ohio, Oregon, Tennessee, California and South Carolina in the 2017 field season. Conventional sprayers were also used for comparison. Insect pests and diseases were assessed weekly at each test site. Host crops were apple, black raspberry, blueberry, wine grapes, peach, serviceberry, crabapple, red maple, dogwood, birch, and sycamore. Chemical use, application time and labor costs were recorded through communication with site managers and sprayer operators. Unmanned aerial systems (UAS) were investigated to identify and quantify diseases and insect pest infestations in the intelligent sprayer field tests. Additionally, soilborne pathogens of seed corn and Fusarium head blight of wheat were also assessed with UAS in collaboration with faculty at Ohio State University. Standard color images and multispectral imagery of test sites were collected regularly throughout the growing season. Four decision support systems (DSS) were evaluated for managing pesticide spray application schedules to control diseases and insect pests in orchards. On-site weather stations were installed to transmit data to the web via a wireless or cellular connection. Approaches were proposed to adaptively implement the orchard DSSs for use in commercial nursery production. Information gathered from the individual insect pest and disease models was combined for future development of a consensus model for spray application recommendations. Statistical analysis was conducted for test data obtained from the evaluation of different classes of spray additives on plant leaf surfaces to improve pesticidal droplet retention and spread. Bio-pesticides of six different classes were tested with three flow capacities of five different types of hydraulic nozzles under laboratory conditions. The six classes of bio-pesticides were horticultural oil, mineral, bacterial, fungal, and insecticidal growth regulator. Droplet size spectrum, spray pattern uniformity, and spray deposition of the bio-pesticides discharged from different nozzles were quantified. Release rates of six different classes of pheromones were measured with an environmentally-controlled precision system at ambient temperatures of 20, 25, 30, 35 and 40 °C and relative humidity of 50%. The measurements were used for development of mathematical models to precisely manage semiochemicals to control forestry pests.


Accomplishments
1. Laser sensor for detection of complex shaped plants. Simultaneous measurements of plant architecture are critical for determining amounts of chemicals in variable-rate spray applications. ARS researchers in Wooster, Ohio evaluated a laser sensor with a specially designed algorithm for its accuracy to detect complex targets. Evaluations included regular shaped objects and irregular-shaped ornamental trees of different sizes at different travel speeds and detection distances. Test results demonstrated that the use of the laser sensor and the specifically designed algorithm was able to accurately measure shapes and sizes of complex target surfaces. Subsequently, air-assisted variable-rate prototype sprayers with the integration of the laser sensor and the algorithm were developed to deliver reduced amounts of sprays to target plants based on the plant canopy structures and sprayer travel speeds in real time; providing an advanced and sustainable approach to pest control. The research received 2017 American Society of Agricultural & Biological Engineers Superior Paper award.

2. Validation of intelligent sprayer for managing pests in nurseries. Conducting on-farm evaluations of pest control and economic feasibility is a necessary procedure to assure successful adoption of new spray technologies by commercial horticulture enterprises. ARS researchers in Wooster, Ohio developed and tested a new intelligent sprayer for control of insect pests in three commercial nurseries in Ohio and Oregon. Efficacy of the sprayer for pest control treatments was compared with two types of conventional air-assisted sprayers. The variable rates from the intelligent sprayer was achieved automatically based on the plant presence, canopy structure and foliage density. Compared to conventional sprayers with comparable and effective insect control, the intelligent sprayer used 30% to 78% less spray volume and chemicals to control pest insects, thereby offering an economically and environmentally responsible spray system to controlling pests.

3. Specially designed sprayer for multiple-row nurseries. Multiple-row planting has been suggested to maximize the number of nursery plants that can be grown in a given area. However, sprayers used for multiple-row nurseries are adopted from other crops; hence, the spray efficiency is very low. Specially designed sprayers are needed to improve pesticide application efficiency and reduce pesticide waste. A laser-guided air-assisted sprayer was designed and evaluated by ARS researchers in Wooster, Ohio to discharge variable-rate sprays for multiple-row nursery crop production. The sprayer was coupled with pulse width modulated solenoid valves to control nozzle flow rates based on tree structures. Field tests demonstrated that the newly developed sprayer could significantly reduce spray volume for multiple-row nursery crop production while providing adequate spray deposition and coverage inside canopies to protect crops against damage from insects and diseases.

4. Computer simulation models to predict sprayer airflow distribution. To improve pesticide application accuracy, it is essential to understand sprayer-induced airflow patterns that carry spray droplets in and around the target canopy as well as at locations far from the targets. An integrated computational fluid dynamics (CFD) model was developed by The Ohio State Univrsity and ARS researchers in Wooter, Ohio to simulate air velocity distributions inside and around tree canopies discharged from a newly developed air-assisted sprayer. The CFD model calculated complex airflow patterns including integration of the sprayer motion and tree canopy architecture. Validation of the CFD model demonstrated that simulated air velocities downwind from the sprayer agreed with the measurements. Consequently, this CFD simulation will provide a new economic approach to understand airflows through tree canopies with complex architectures and leaf densities, and will be used to assist sprayer design and guide spray application practice.


Review Publications
Liu, H., Zhu, H. 2016. Evaluation of a laser scanning sensor on detection of complex shaped targets for variable-rate sprayer development. Transactions of the ASABE. 59(5): 1181-1192.
Lin, H., Zhou, H., Xu, L., Zhu, H., Huang, H. 2016. Effect of surfactant concentration on the spreading properties of pesticide droplets on Eucalyptus leaves. Biosystems Engineering. 143: 42-49.
Zhu, H., Rosetta, R., Reding, M.E., Zondag, R., Ranger, C.M., Canas, L., Fulcher, A., Krause, C.R., Derksen, R.C., Ozkan, E. 2017. Validation of laser-guided variable-rate sprayer for managing insects in ornamental nurseries. Transactions of the ASABE. 60(2): 337-345.
Yu, R., Zhao, L., Hadlocon, L.S., Zhu, H., Ramdon, S.K. 2017. Laboratory evaluation of electrostatic spray wet scrubber to control particulate matter emissions from poultry facilities. Environmental Technology. 38(1):23-33.