Extension Vegetable Crops Specialist
Kearney Agricultural Center
9240 S. Riverbend Avenue
Parlier, CA 93648
Tel (209) 891-2660
Fax (209) 891-2593
BA, Occidental College, Philosophy, 1974
MS, University of California, Davis, 1988
PhD, University of California, Davis, 1995
Assistant Extension Specialist, Dep't. of Vegetable Crops, University of
California, Davis, 1994 - Present
Research and Outreach
My current research and extension program focuses on soil and water
management in vegetable production systems throughout California,
impacts of preharvest vegetable management practices on postharvest
product quality and extension methodology.
A major component of my research and extension effort involves leading
an interdisciplinary team consisting of UC Farm and IPM Advisors,
campus-based researchers, and 12 farmers in the San Joaquin Valley's
West Side region that is currently conducting on-farm demonstrations
and evaluations of biologically integrated farming practices in the
annual cropping systems of this region. The objectives of this work
are 1) to facilitate information exchange among participating farmers,
consultants and researchers on soil building practices and options for
reduced reliance on agrichemical inputs, 2) to monitor and evaluate
on-farm demonstrations of soil building practices, including cover
cropping and organic soil amendment inputs, 3) to determine the extent
to which IPM practices are utilized in row crops on the West Side and
identify constraints preventing further adoption of biologically
intensive pest management practices and 4) to provide community based
demonstrations of existing technologies to overcome constraints while
making use of participatory research teams to develop and refine
An important research component of this on-farm demonstration project
involves the evaluation of surface organic mulches in no-till
vegetable production systems. I am currently conducting a
wide-ranging program in this area to evaluate the effectiveness of
these practices for: suppressing weeds, improving production
efficiencies in terms of nutrient inputs and irrigation water, and for
providing optimal soil temperature regimes for crop growth.
Mitchell, J.P., C. Thomsen, W. Graves and C. Shennan. Cover Crops for
Saline Soils. J. Agron. & Crop Sci. (Accepted)
Mitchell, J.P., D.W. Peters and C. Shennan. Changes in Soil Water
Depletions in Winter Fallowed and Cover Cropped Soils. (To be
Mitchell, J.P. 1995. A Cropping Systems Approach to Improving Water
Use Efficiency in Semi-Arid Irrigated Production Areas. PhD
Dissertation. University of California Davis. 137 pp.
Mitchell, J.P., C. Shennan and S.R. Grattan. 1991. Developmental
Changes in Tomato Fruit Composition in Response to Water Deficit and
Salinity. Physiologia Plantarum. 83:177-185.
Mitchell, J.P., C. Shennan, S.R. Grattan and D.M. May. 1991. Tomato
Fruit Yields and Quality Under Water Deficit and Salinity. J. Amer.
Soc. Hort Sci. 116(2):215-221.
Mitchell, J.P., C. Shennan, D. May, J. Mitchell and R. Burau. 1987.
Use of Drainage Water for Irrigation of Melons and Tomatoes.
California Agriculture. 41: 27-28.