2007 Annual Report 1a.Objectives (from AD-416) Determine biological and microclimate factors that affect application of pest control agents. Determine effects and interactions of spray-adjuvants and plant leaf surface structure on spray droplet retention and resulting efficacy. Determine the effects of meteorological, sprayer and crop conditions on coverage and drift from air-assisted spraying. Develop system for detecting/tracking insect populations and for injecting soilborne insect control formulations. 1b.Approach (from AD-416) Use electron beam analysis to assess disease factors that limit integrated crop management systems as related to application of control agents in greenhouse/nurseries. Residues of pesticides of leaf or inert sampling surfaces will be evaluated relative to factors that affect deposit and uptake. Study foliar microstructure/spray impaction processes; assess effects of spray-solution properties, especially surfactants, and leaf surface morphology factors that govern spray retention. Assay foliar coverage, ground deposits, and airborne drift from several types of air-assisted sprayer in orchards and nurseries. Investigate acoustical detection of soilbornes insect larvae in nursery soils to determine whether sensing of larvae presence is feasible; use radar tracking to help determine behavioral patterns of adult nursery insects. 3.Progress Report A wide-swath air jet sprayer was investigated in an effort to use optimal spray techniques to effectively control pest insects or diseases for container ornamental crops. Air velocity, spray deposition, spray coverage and spray spot density on artificial targets inside and outside hydrangea plants at two heights across the spray swath were evaluated and correlated. The maximum spray range that plants can be adequately sprayed was also investigated. Treatments included three flow rates, three travel speeds, and two different nozzle settings. Trials of half amounts of chemicals for both insect and disease controls in nursery production were conducted in four nurseries in northern Ohio. Leaf samples were collected and the amounts of chemical residues on leaves were analyzed for the half-rate and full-rate chemical trials. Leaf samples were also collected for scouting damages by insects and diseases. Mathematical models were developed to assist the development of a canopy opener that would optimize spray penetration into soybean plants. Spray deposition and coverage inside soybean canopies were compared with various types of nozzles and application rates from an air assisted sprayer and a conventional boom sprayer. Laboratory-based research was launched and sequential images for the evaporation process of water droplets mixed with different chemical formulations in a small environmental chamber were obtained through a stereoscope under the experimental conditions with five droplet sizes and three relative humidity conditions. The spray mixtures included different combinations of water, a nonionic colloidal polymer drift retardant, a nonionic surfactant, insecticides and fungicides. A simple, user-friendly pressure gauge tester was investigated and modified for calibration of pressure gauges used on pesticide sprayers and irrigation lines. The modified tester consists of a hand pump, a small water reservoir, a factory calibrated gauge, and a port for the tested gauge. The tester was introduced to the extension experts for field trials. Water and fertilizer use and loss as well as tree growth were investigated for Red Sunset maple trees in a pot-in-pot system with two different potting media and one coal ash based medium. The two potting media mainly composed of aged pine bark and steamed composted nursery trimmings as well as left-over potting mix from commercial nurseries, but one with high initial amendments and the other one with low initial amendments. The coal ash based medium was mainly composed of biosolids, flue gas desulfurization gypsum, and coal combustion bottom ash. Trickle irrigation was applied to each tree with a new automatic control system developed by ourselves. Water and fertilizer use and loss as well as tree growth were investigated for pears and redbud trees in a pot-in-pot system with six different irrigation control strategies and three different fertilizer treatments. The potting substrate water content and temperature were also measured for monitoring tree growth conditions. 4.Accomplishments Mathematical models to assist canopy opener development. Conventional sprayers have limited capability to deliver sufficient chemicals to inner canopies when the foliage at the top of the canopy is very dense. The hypothesis was postulated that spray deposition inside dense canopies from conventional boom sprayers could be improved by mounting a straight pipe ahead of spray nozzles. Mathematical models were developed to assist the development of a canopy opener that would optimize spray penetration into soybean plants. The models can estimate optimum opener depth and width required to create sufficient plant deflection for droplets to reach target areas inside canopies. With insight from models, the development process can be simplified and possible errors may be avoided. The accomplishment of this research is directed towards ARS National Program 305 – Crop Production, Research Component II – Agroengineering, Agrochemical, and Related Technology. Investigation of optimal spray techniques for nursery applications. In many cases, container-grown crops are managed in plastic-covered greenhouses. The plastic covers are used in winter while they are removed during the warm growing season. Conventional sprayers cannot efficiently apply pesticides to many container ornamental crops due to the special planting circumstance. A wide-swath air jet sprayer was investigated for the use in nurseries. The uniformity of spray deposition, coverage and air velocity distribution across the spray swath from the sprayer were determined and correlated. Investigation also included determination of the maximum spray range from the sprayer that plants can be adequately treated. Under the calm weather conditions, the wide-swath air jet sprayer can provide fairly uniform spray distributions across the spray swath. This study will assist nursery growers to identify optimal spray techniques to effectively control pest insects or diseases for container ornamental crops. The accomplishment of this research is directed towards ARS National Program 305 – Crop Production, Research Component II – Agroengineering, Agrochemical, and Related Technology. Investigation of evaporation and residual formation of spray droplets containing additives. Pest control efficiency is greatly influenced by plant fine surface structure and plant growing conditions. For the plants with thick, waxy or hairy leaf surfaces, the addition of surfactants in spray solutions can minimize variations in spray performance and improve pesticide effectiveness. It is important to understand the evaporation and spread of pesticide droplets on targets for increasing the control efficiency of foliar applied insecticide and fungicide spray applications. Evaporation process and residual patterns of water droplets mixed with a nonionic surfactant in a small environmental chamber were obtained through a stereoscope under the experimental conditions with various droplet sizes and relative humidities. Spray performances can be improved when pesticide spray mixtures containing surfactants are applied under high relative humidity conditions. High concentration of surfactants produces large residual spots and can increase the potential of phytotoxicity on plants. It is important to choose proper concentration of surfactants for desired plants. The accomplishment of this research is directed towards ARS National Program 305 – Crop Production, Research Component II – Agroengineering, Agrochemical, and Related Technology. Development of a user-friendly pressure gauge tester. Pesticide spray applicators and irrigation managers always use pressure gauges as an indicator to regulate the amount of chemical solutions for spraying and the amount of water for irrigation. Many pressure gauges become defective after being used for a while in the field. Defective pressure gauges cause plants either over or under applied with pesticides and water. It is essential to frequently check the accuracy of pressure gauges on the sprayers or in the irrigation lines. In this research, a pressure gauge tester originally used in industrial applications was investigated and modified for the calibration of pressure gauges used in agricultural fields. Pesticide spray applicators now can use it to accurately apply pesticides for effective control of insects or diseases, and irrigation managers can use it to accurately monitor irrigation practices for efficient use of water. The accomplishment of this research is directed towards ARS National Program 305 – Crop Production, Research Component II – Agroengineering, Agrochemical, and Related Technology. 5.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. 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. 6.Technology Transfer Number of active CRADAs and MTAs 1 Number of web sites managed 4 Number of non-peer reviewed presentations and proceedings 3 Number of newspaper articles and other presentations for non-science audiences 3 Review Publications Zhu, H., Brazee, R.D., Derksen, R.C., Fox, R.D., Krause, C.R., Ozkan, H.E., Losely, K.E. 2006. A specially designed air-assist sprayer to improve spray penetration and air jet velocity distribution inside dense nursery crops. Transactions of the ASABE. 49(5):1285-1294. Zhu, H., Frantz, J., Derksen, R.C., Krause, C.R. 2007. Investigation of Drainage and Plant Growth from Nursery Container Substrate. Applied Engineering in Agriculture. 23(3):289-297. Guler, H., Zhu, H., Ozkan, H.E., Derksen, R.C., Yu, Y., Krause, C.R. 2007. Spray characteristics and drift reduction potential with air induction and conventional flat fan nozzles. Transactions of the ASABE. 50(3):745-754.