California Department of Transportation

Weed and Pest Control Research

Weed Control

Invasive and noxious species are studied to prevent and control their spread within and from the highway right-of-way.

Vegetation Management Weed Mat Trial, 2008

This field trial research project studies the performance of a permanent vegetation control product (weed mat). Potential benefits of this field trial include improved weed control, reduced herbicide use and reduced potential of herbicides in storm water runoff.


This study evaluates several established sequences to determine effective ways to convert exsisting annual non-native vegetation to native perennial species.

Enhanced Biological Control of Yellow Starthistle and Tumbleweed (Russian Thistle), 2006

This study evaluates host plant specificity and potential efficacy of proposed insect and mite biological control agents of two invasive alien weeds, yellow starthistle and tumbleweed.

Exploring Alternate Methods for Vegetation Control and Maintenence aloNg Roadsides, 2003

The use of synthetic herbicides on Caltrans managed acreage has raised concerns over environmental quality, public health, and worker safety, especially in the North Coast area of California. Alternative methods of vegetation control were studied to determine their efficacy and economic feasibility.

Biological Control of Cape Ivy, 2002.

This report documents the status of the development of biological control agents for Cape ivy. Research of promising insects and pathogens has demonstrated reduction in biomass and structure of Cape ivy plants.

International Broom Initiative, 2002.

This is the final report on work carried out for the biological control of French broom in California by Commonwealth Scientific and Industrial Research Organization at it European Laboratory in France in collaboration with the USDA European Biological Control Laboratory.

Biological Control of Weeds, 2002.

This report summarizes the research during the calendar years 1999 and 2000 that was directed by Research Entomologist, Joseph Balciunas, at the USDA-ARS Exotic & Invasive Weed Research Unit in Albany, California. The primary project during this period was Yellow Starthistle.

An Integrated Pest Management Plan for Control of the Eucalyptus Longhorned Borer in California. December 1994

This report documents the integrated pest management program for control of the Eucalyptus Longhorn Borer. The basic biology of the insect and silvicultural practices are critical for limiting risk of infestations. Site conditions and tree maintenance are important contributors to species susceptibility or resistance. The introduction and establishment of parasitic wasps offers a cost effective, safe and permanent reduction in beetle populations


Updated 07-11-2012