Steven A. Fennimore

Steven Fennimore

Position Title
Professor of Extension

  • Faculty
UC Davis, One Shields Ave, Davis CA 95616


  • Ph.D., Purdue University; Weed Science, 1997
  • M.S., University of California, Davis; Weed Science, 1983
  • B.A., University of Oregon; Public Affairs, 1977

Research interests and expertise: 

Steve Fennimore is an Extension Specialist with UC Davis located at Salinas, California. Since 1997, Steve has conducted a research and extension program focused on weed management in vegetables, flowers and strawberries, and he spends most of his time working in coastal production areas between Watsonville and Oxnard, California. His program combines chemical and nonchemical methods, for both organic and conventional systems with the objective of containing or reducing weed management costs. More recently, his program focuses on development of automated weeding systems to mitigate the severe labor shortages in California, and development of field scale steam applicators to reduce the need for chemical fumigation in sensitive sites and near urban areas.

Current projects:

  • Effects of proposed regulations by CDFA on weed management programs in vegetables (proposed project); CDFA, 2018ñ2021
  • Weed management in strawberry (current project); California Strawberry Commission, 2017ñ2018
  • Weed management in leafy greens (current project); California leafy Greens Research Program, 2017ñ2018
  • Crop signaling for automated weed/crop differentiation and mechanized weed control in vegetable crops (current project); USDA NIFA Specialty Crops Research initiative, 2014ñ2018
  • Production of strawberry in soils disinfested with enhanced steam and allyl isothiocyanate (current project); USDA NIFA Methyl Bromide Transitions, 2015ñ2018
  • Integration of allyl-isothiocyanate, steam and exothermic substances for soil disinfestation in strawberry nurseries (current project); USDA NIFA Methyl Bromide Transitions, 2017ñ2020
  • Use of precision-applied steam to control soilborne pathogens and weeds in lettuce (current project); USDA NIFA Crop protection and pest management, 2017ñ2020
  • Weed management in strawberry (pending project); California Strawberry Commission, 2018ñ2019
  • Weed management in leafy greens (pending project); California Leafy Greens Research Program, 2018ñ2019

Outreach and Extension:

  • Currently I am director of the Vegetable Research and Information Center, a website that provides information on vegetable production in California.
  • My Extension program consists of providing support for UC farm advisors, primarily those that work on vegetables and strawberry.
  • Additionally, I provide support for the UC IPM program publications on pest management.
  • I am an active participant in the UC Vegetable and Pest management program teams as well as the UC Weed workgroup. I am current chair of the Vegetable Program Team

External activities that contribute to scholarship:

  • Associate Editor, Weed Technology, since 2003
  • Current chair, WSSA Committee on Research and Competitive Grants

Prizes, Awards, Honors:

  • Fulbright Scholar Award Uruguay on Weed management, 2019
  • California Weed Science Society Award of Excellence, 2016
  • Oscar Lorentz Award, 2015


  • Lettuce
  • Strawberry
  • Vegetable weed control
  • Soil disinfestation
  • Steam
  • Automated weed control
  • Nonchemical weed control