DANIEL DOWNEY, Assistant Research Engineer

Ph.D., Biological and Agricultural Engineering, University of California, Davis, 1997
Department of Biological and Agricultural Engineering
1334 Bainer Hall
Phone: 530-754-9594
Email: ddowney@ucdavis.edu

Current Research

Dr. Downey’s research interests focus on micro-spray applications for weed control, real time chemical injection and fluid mixing characteristics coupled with weed imaging for target identification, and monitoring the performance of industrial and agricultural spray applications electronically and chemically. Tools used and developed include: integrating data acquisition and GPS equipment for electronic data collection; development of an image analysis program for determining statistical characteristics of spray deposition on liquid sensitive surfaces; system instrumentation for monitoring concentration, pressure, and flow.

Recent work has focused on developing an in-line monitoring system that can be used on harvesters to compare relative dust intensity during nut pick-up operations. The system developed can be used to establish differences in machine design, harvester operating conditions and orchard management practices. The system provides real-time information and feed-back during harvest operations and allows a fast, low cost evaluation of changes in machine design, operation or other cultural factors. The measurements for this in-line monitor can be used to screen promising dust reduction technologies so that extensive testing can be focused on other dust measurement activities.

GPS/GIS mapping of agricultural systems has increased considerably over the last decade. Yield, weed, and chemical application mapping procedures can be used to assess and potentially increase agricultural production. Additional work is focused on assessing effects of different cultural practices and harvest activities and converting GPS data sets for descriptive map development.

Deposition studies for spray drift control of agrochemical transport associated with encroaching urban areas is a tractable research problem. We have used real time weather monitoring capabilities along with GPS data capture to show the effects of these processes. Additional work has been done within the laboratory to characterize spray drift from common agricultural systems, in addition to assessments from commercial dispensers for consumer and personal care products. These techniques include use of a wind tunnel for transport of aerosols and sprays, air sampling materials, tracer development and analysis techniques for mass transfer, laser diffraction devices for particle size distributions, and respirable fraction characterizations of aerosols.

Representative Recent Publications

Giles, D. K., and D. Downey. 2003. Quality control verification and mapping system for chemical application. Journal of Precision Agriculture 4(1):103-124.

Gillis, K. P., D. K. Giles, D. C. Slaughter, and D. Downey. 2003. Injection mixing system for a boomless, target-activated herbicide sprayer. Transactions of the ASAE (American Society of Agricultural Engineers) 46(4):997-1008.

Giles, D. K., D. Downey, and D. C. Slaughter. 2004. Liquid property and nozzle effects on flight time of pulsed jet spray. Atomization and Sprays 14(2):111-126.

Downey , D., D. K. Giles, and D. C. Slaughter. 2004. Pulsed jet micro-spray applications for high spatial resolution of deposition on biological targets. Atomization and Sprays 14(2):93-110.

Giles, D. K., D. Downey, D. C. Slaughter, J. C. Brevis-Acuna, and W. T. Lanini. 2004. Actuator for micro-dosing of weeds in row crops: physical and biological performance. Applied Engineering in Agriculture 20(6):735-743.

Giles, D. K., and D. Downey. 2004. Dormant spray study: In-orchard distribution of spray liquid and benefits of “Smart Spray” technology. Project Report for Central Valley Regional Water Quality Control Board, Sacramento, CA, May.

Downey , D., D. K. Giles, and D. C. Slaughter. 2004. Mapping weeds using DGPS and ground based vision identification. California Agriculture 58(4):218-221.

Giles, D. K., D. Downey, and L. M. Squire. 2005. Transient droplet size spectra from trigger sprayers dispensing aqueous solutions. Transactions of the ASAE (American Society of Agricultural Engineers) 48(1):63-72.

Giles, D. K., D. Downey, H. Scher, D. Winetzky, and T. Becker. 2005. Suppression of aerosol generation during spraying and deposition of consumer products. Atomization and Sprays. In Press.

Crowe, T. G., D. Downey, D. C. Slaughter, and D. K. Giles. 2005. An electronic sensor to characterize transient response of nozzle injection for pesticide spraying. Transactions of the ASAE (American Society of Agricultural Engineers) 48(1):73-82.