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Alternatives to Methyl Bromide Soil Fumigation in California
Pesticide Fact Sheet - January 1996
Methyl bromide (MeBr) is a widely used pesticidal gas. Some 15 to 20
million pounds are used each year in California, primarily for pre-plant
soil fumigation. Methyl bromide is being phased out internationally because
it depletes stratospheric ozone, which protects life on Earth from the
harmful effects of the sun's ultraviolet radiation.
Some have argued that methyl bromide is so important to agriculture that we
cannot stop using it, even if it is dangerous to people and the
environment. However, banning methyl bromide would have only a small effect
on most of California agriculture. In addition, many alternatives to methyl
bromide exist and are already in widespread use.
Major Uses of MeBr
Soil fumigation is the largest use in California.(1)
Type of Fumigation Total Uses in California
Major Uses of MeBr for Soil Fumigation, by Crop(2)
Only a few crops account for most of the use of methyl bromide.
Crop Share of California's MeBr Use for Soil
nursery/greenhouse crops 15%
Losses if Methyl Bromide is Banned
The United States Department of Agriculture estimates only minimal crop
losses in California if methyl bromide is banned. Yields for strawberries
are expected to drop by 14%. For all other crops, declines in yield of only
1 to 3% are predicted.(3)
Alternatives to Methyl Bromide Soil Fumigation
In 1995, the United Nations Methyl Bromide Technical Options Committee
concluded that alternatives exist or are at an advanced stage of
development for more than 90% of methyl bromide use. The Committee, made up
of 68 experts from 23 countries, identified a wide range of alternatives
for many uses of methyl bromide.(4)
For every crop that uses methyl bromide, there are examples of the same
crop being grown successfully and for profit without methyl bromide in
California, in other states, and in other countries. For example:
* Less than half of the California grape acreage planted each year is
fumigated with methyl bromide. Instead, growers monitor for pests and
do not apply pesticides if pests are not present. If pests are
present, growers manage them with fallow periods, resistant
rootstocks, cover crops and compost applications to improve soil
quality, and pesticides other than methyl bromide.(5)
* Strawberries are grown on a large scale without methyl bromide in The
Netherlands. Some are grown in greenhouses and about five thousand
acres are grown in the field. Average yields are higher than those
obtained in California. Instead of methyl bromide, the Dutch growers
use soilless potting mixes, high density plantings and fungicides.(6)
* A number of large nursery companies in California have started to use
compost instead of methyl bromide.(7) The Ohio nursery industry gave
up methyl bromide 20 years ago, primarily because they found it
expensive and unnecessary. Instead, growers use compost to suppress
soil-borne diseases. Compost is made from a variety of sources,
including urban green waste, and transforms a waste problem into a
* Steam is a highly effective control for soil-borne pests in greenhouse
nursery crops. In California, steam was largely replaced by methyl
bromide, but in other states and countries, steam treatments are still
in use and have been improved to make them cheaper and more effective.
Machines are also commercially available and in use for treating field
plots of high-value nursery crops.(8)
* Several forest tree nurseries in California and other parts of the
Western US and Canada have stopped using methyl bromide. Instead, the
nurseries use dazomet, a soil pesticide that does not deplete the
ozone layer. Costs and production efficiencies are comparable to using
methyl bromide. Other forest nurseries grow seedlings in soilless
mixes in the greenhouse, and use no methyl bromide. In all, 100% of
the forest tree seedlings in western Canada, and 40% of the seedlings
in the western U.S. are grown without any methyl bromide.(9)
This Fact Sheet was prepared by James Liebman, Ph.D., a plant pathologist
and Staff Scientist at the Pesticide Action Network North America Regional
Center, 116 New Montgomery Street #810, San Francisco, CA 94105; (415)
541-9140; fax (415) 541-9253; email firstname.lastname@example.org
1 Department of Pesticide Regulation. 1994. Annual Pesticide Use Reports,
1993. California Environmental Protection Agency, Sacramento, CA.
3 National Agricultural Pesticide Impact Assessment Program. 1993. Biologic
and Economic Assessment of Methyl Bromide Ban. United States Department of
Agriculture, Washington, DC.
4 Methyl Bromide Technical Options Committee. 1995. 1994 Report of the
Methyl Bromide Technical Options Committee for the 1995 Assessment of the
UNEP Montreal Protocol on Substances that Deplete the Ozone Layer. United
Nations Environment Programme
5 Liebman, J. and S. Daar. 1995. Alternatives to methyl bromide in
California grape production. IPM Practitioner 17(2):1-12.
6 Liebman, J. 1994. Alternatives to methyl bromide in California strawberry
production. IPM Practitioner 16(7):1-12. DeBarro, P.T. and B. Edwards.
1996. Strawberry Production in the Netherlands Without Methyl Bromide, in
Agricultural Production without Methyl Bromide - Four Case Studies. H.J.
Banks, ed. CSIRO Division of Entomology, Australia.
7 Quarles, W. and J. Grossman. 1995. Alternatives to methyl bromide in
nurseries-disease suppressive media. IPM Practitioner 17(8):1-13.
8 Grossman, J. and J. Liebman. 1995. Alternatives to methyl bromide-steam
and solarization in nursery crops. IPM Practitioner 17(7):1-12.
9 Anonymous. 1995. Alternatives to Methyl Bromide: Ten Case Studies-Soil,
Commodity, and Structural Use. Stratospheric Ozone Protection, Office of
Air and Radiation, US Environmental Protection Agency, Washington, DC.
Liebman, J. 1994. Integrating research and practice: implementing
alternatives to methyl bromide soil fumigation in California agriculture.
Presentation at the Annual International Research Conference on Methyl
Bromide Alternatives and Emissions Reductions, November 13-16, 1994,
Orlando, Florida, sponsored by Methyl Bromide Alternatives Outreach.
Pesticide Action Network North America (PANNA), 116 New Montgomery, #810,
San Francisco, CA 94105; phone (415) 541-9140; fax (415) 541-9253; email
Methyl Bromide Briefing Kit (by gopher)
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