Hero Image

Brent A. Holtz Ph.D.

County Director and Farm Advisor
Cooperative Extension San Joaquin County
2101 East Earhart Avenue, Suite 200
Stockton, CA 95206
(209) 953-6124
baholtz@ucanr.edu Create VCard


Dr. Brent Holtz has been an Orchard Systems Farm Advisor for the University of California for 30 years and County Director in San Joaquin County’s UC Cooperative Extension office for 15 years.  Brent was raised on an almond ranch in the Northern San Joaquin Valley, attended schools in California: Modesto Junior College, California Polytechnic State University, San Luis Obispo (B.S.), and earned both M.S. and Ph.D. degrees in Plant Pathology from the University of California, Berkeley.  Following graduation in 1993, Dr. Holtz was a post-doctoral research associate with Dr. Themis Michailides at the University of California, Davis, before becoming the Orchard Systems Farm Advisor in Madera County in 1994. 

Brent's research and education programs are focused on growing almond and pistachio in the San Joaquin Valley of California, helping growers in production agriculture find more sustainable farming practices without compromising product quality or yield.  Brent is currently leading a research effort on whole orchard recycling (WOR) where removed orchards are ground-up and incorporated into the soil to increase soil organic matter and soil water holding capacity, instead of being burned in the field or a co-generation facility (‘Resilience: the whole orchard recycling origin story’).  Brent is currently serving on San Joaquin County’s Agricultural Advisory Board, the San Joaquin Farm Bureau Federation Board of Directors, and the California Clean Biomass Collaborative, with a mission of finding alternatives to agricultural burning.


Ph.D. Plant Pathology, UC Berkeley. 1993
M.S. Plant Pathology, UC Berkeley. 1989
B.S. Biology, Plant Pathology, Entomology, California Polytechnic State University, San Luis Obispo. 1986
A.A. Science and Mathematics, Modesto Junior College. 1983


  • Finalist, Fresno, CA
    Presented by Friends of Agriculture,  2002
  • Proclamation of Achievement Award
    Presented by Madera County Board of Supervisors,  2002
  • National Achievement Award, Albuquerque, New Mexico,
    Presented by National Association of County Agricultural Agents,  2001


Pomology, deciduous tree fruits and nuts, plant pathology, Whole Orchard Recycling

Areas of Expertise (click to see all ANR academics with this expertise)


Peer Reviewed

California Agriculture Article Contributions

ANR Workgroup Associations

Return to School Garden Consultation