Vegetable Research & Information Center, UC Cooperative Extension

Staff of the Center

The UC Vegetable Research and Information Center (VRIC) was organized to provide a statewide program to which all University of California personnel with any research or extension activities related to vegetable production, postharvest handling, marketing or consumption could affiliate. A second primary purpose to provide the vegetable industry, related industries, and others interested in vegetables, with a focal point to which they could obtain information and establish appropriate linkages with the University. The expected results are improved effectiveness and efficiency within UC; and improved collaboration, linkage and communication between UC and the vegetable industry, and between UC and other interested vegetable constituencies.

The VRIC Director provides leadership to accomplish short and long term goals; convenes and leads the internal Steering and external Advisory Committees to determine Center priorities, and develops and implements strategies for addressing those priorities. Past VRIC Directors were Ron Voss and Don Nevins.

VRIC Staff
Timothy K. Hartz, Director, VRIC (May 2007-present)
Gale Perez , Program Representative

Timothy HartzTimothy K. Hartz

Extension Specialist/Agronomist
University of California, Davis
Dept. of Plant Sciences
103 Asmundson Hall
Phone: (530) 752-1738
Fax: (530) 752-9659


BS, Bowling Green State University, Biology, 1973
MS, Colorado State University, Horticulture, 1977
PhD, Virginia Polytechnic Institute, Horticulture, 1980

Professional Experience

Extension Specialist, Dept. of Horticulture, Texas A&M Univ., 1981-87
Extension Specialist, Dept. of Botany & Plant Science, UC Riverside, 1988-91
Extension Specialist, Dept. of Plant Sciences, UC Davis, 1991-Present

Research & Outreach

I conduct an applied research and outreach program to aid California's large, diverse commercial vegetable industry. The overall goal of my program is to help the industry maintain productivity and profitability, while meeting the mounting environmental and political pressure to adopt more sustainable production practices. My research focus is on improving irrigation and fertility management. 

California agriculture will face increasing competition for water from urban and environmental interests. Conversion from conventional furrow or sprinkler irrigation to drip irrigation is one approach to improve water use efficiency; currently at least 40,000 ha of vegetables are drip irrigated annually in the state, and the pace of conversion is accelerating. We have studied many aspects of drip irrigation management: irrigation scheduling (Breschini and Hartz, 2002; Hartz, 1993, 1997), fertigation (Hartz et al, 1994) nutrient monitoring (Hartz et al, 1993), modified tillage practices, etc. The results of these investigations have been widely disseminated, and have had substantial impact on the commercial vegetable industry, in California and beyond. 

Conventional vegetable production relies heavily on synthetic fertilizer inputs, particularly nitrogen. Inefficient fertilizer use is not only a waste of a non-renewable resource, but also a significant contributor to groundwater pollution. I have worked extensively to document crop nutrient requirements under conventional production practices, and to develop practical diagnostic techniques (for both laboratory and on-farm use) to improve fertility management (Breschini and Hartz, 2002; Hartz et al., 2001 a, b; Hartz et al., 2002). Examples of these diagnostics include: petiole sap analysis for NO3-N, and an alternative soil K test based on the rate of K release. 

In my role as Extension Specialist I provide support to industry groups, individual growers, and county-based UC Farm Advisors on a wide range of vegetable production problems. This support takes several forms: diagnosing individual field problems, conducting field trials and demonstrations, organizing field days and educational meetings, etc. The bulk of my activities relate to cucurbits, solanaceous crops, lettuce, and celery.

Gale Perez

Program Representative
University of California, Davis
Dept. of Plant Sciences
154 Robbins Hall
Phone: (530) 752-1748
Fax: (530) 752-4604

Professional Experience

Gale began her UC career in 1987 at the Cooperative Extension: Entomology office with Shirley Humphrey, Eric Mussen, Vernon Burton, and Russell Fontaine. She managed the registration process for the UC Pest Management Seminars. With the reorganization, the UC Pest Management Seminars and Gale were relocated to the Statewide IPM Program and were under the supervision of Pat O’Connor-Marer. Gale has traveled as far north to Klamath Falls and Tulelake and as far south to Holtville and San Diego working with farm advisors and specialists to provide continuing education to pest control advisers. For the next 15 years, Gale continued working with O’Connor-Marer and his Pesticide Safety Education Program.

In the Fall of 2004, Gale moved on to work at the UC Davis Extension’s International Law Programs unit. She oversaw the logistics and registration process of three summer programs for lawyers, judges, and other legal professionals from other countries.

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