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United States Department of Agriculture

Agricultural Research Service

Title: Fumigant Use in California – Response to the Phase-Out

Author
item Trout, Thomas

Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: October 20, 2006
Publication Date: November 6, 2006
Citation: Trout, T.J. 2006. Fumigant use in california – response to the phase-out. International Conference on Methyl Bromide Alternatives and Emissions Reductions.

Interpretive Summary: Fumigants are used to kill pests in soils before planting and in commodities before storage or shipping. Methyl bromide (MeBr), one of the most effective fumigants, is being phased out because it contributes to depletion of atmospheric ozone. The phase-out began in 1999 and was completed in 2005. Use of MeBr declined gradually between 1991 and 1999, the first year of the phase-out. In 2000 and 2001, use dropped dramatically to below phase-out levels as a result of a price increase and restrictive California regulations. MeBr use in 2003 and 2004 exceeded the phase-out limit through use of material carryover from prior years and Quarantine Exemptions. Although 2005 completed the phase-out, 6.4 million pounds was used in California under critical use and quarantine/pre-shipment exemptions – nearly the same amount as had been used annually since 2001. The MeBr reduction has been achieved primarily through full or partial substitution of alternative fumigants, and total fumigant use in California has remained relatively constant since 1991. Since Telone was re-introduced in California in 1995, use of this product has increased substantially and it’s use now exceeds MeBr. Chloropicrin use increased due to increasing proportions of chloropicrin in MeBr/chloropicrin mixtures. Metam sodium is the most widely used fumigant in California, but is not often used as a replacement for MeBr.

Technical Abstract: The Pesticide Use Reporting (PUR) requirements in California allow tracking of the uses of methyl bromide (MeBr) and alternative fumigants during the MeBr phase-out. Use of MeBr declined gradually between 1991 and 1999, the first year of the phase-out. In 2000 and 2001, use dropped dramatically to below phase-out levels as a result of a price increase and restrictive California regulations. MeBr use in 2003 and 2004 exceeded the phase-out limit through use of material carryover from prior years and Quarantine Exemptions. Although 2005 completed the phase-out, 6.4 million pounds was used in California under critical use and quarantine/pre-shipment exemptions – nearly the same amount as had been used annually since 2001. The MeBr reduction has been achieved primarily through full or partial substitution of alternative fumigants, and total fumigant use in California has remained relatively constant since 1991. Since 1,3-D was re-introduced in California in 1995, use of this product has increased substantially and it’s use now exceeds MeBr. Chloropicrin use increased due to increasing proportions of chloropicrin in MeBr/chloropicrin mixtures. Metam sodium is the most widely used fumigant in California, but is not often used as a replacement for MeBr.

Last Modified: 9/10/2014
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