Methyl bromide is a broad-spectrum fumigant that is widely used to control insect, pathogen, nematode, weed and rodent pests. Approximately 90% of the methyl bromide use in California is for pre-plant soil fumigation to control soilborne pathogens and pests principally in strawberries, nursery crops, grapes, and tree fruits and nuts. Postharvest commodity treatment accounts for about 5-10% of the methyl bromide use and is directed largely at insects of nuts, cherries, grapes, raisins, and imported materials. Structural fumigation accounts for most of the remainder of the methyl bromide use in California.

Methyl bromide has been identified as an ozone-depleting substance, with an ozone-depleting potential of 0.6. Under the Clean Air Act, the U.S. Environmental Protection Agency has prohibited the production and importation of methyl bromide starting January 1, 2005. In addition, the United States has joined 140 other nations in signing the Montreal Protocol, which in 1994 froze production and importation of methyl bromide at 1991 levels, and which requires use to be reduced in developed countries by 25% in 1999, 50% in 2001, 70% in 2003 and 100% in 2005.

Thus, this widely used pesticide for the production and export of high value crops and commodities in California will be lost within the next few years. [ML3] Several potential chemical and non-chemical alternatives to methyl bromide have been identified nationally and internationally and some of these alternatives are currently being evaluated in California. However, none of the alternatives have been adequately shown to be as effective or economical as methyl bromide within California farming systems. Therefore, there is an urgent need to develop and evaluate effective, economical alternatives to the agricultural use(s) of methyl bromide as a pre-plant soil fumigant and postharvest commodity and quarantine treatment.

Since 1999, SAREP has supported research and implementation of alternatives to methyl bromide within California farming systems. 

2012-2015 funded research:

Sustainable Strawberry Production in the Absence of Soil Fumigation

This project evaluates strawberry cultivars and the use of compost in non-fumigated soil in three different California geographic regions. The performance of strawberry cultivars will be evaluated by measuring yield and fungal damage. The results of this project will help to guide growers in selection of cultivars and the use of compost to optimize production.

Partially funded by SAREP, the study is managed by plant pathology graduate student Margaret Lloyd and plant pathology Professor Tom Gordon.

Visit the project website.

1999 funding for alternatives to Methyl Bromide

Full project reports 

Background

Background information on Methyl Bromide phase out

U.S. EPA methyl bromide phase out website

UC ANR: Alternatives to Methyl Bromide

Pacific-Area Methyl Bromide Alternatives Program

Resources

Selecting Legume Cover Crops When Managing Verticillium Wilt