Author
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Trout, Thomas |
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Submitted to: Proceedings California Plant and Soil Conference Farming in Crisis
Publication Type: Proceedings Publication Acceptance Date: 2/5/2002 Publication Date: 3/1/2002 Citation: Trout, T.J. 2002. METHYL BROMIDE-ALTERNATIVES FOR CALIFORNIA. Proceedings California Plant and Soil Conference Farming in Crisis. Interpretive Summary: Preplant soil fumigation with methyl bromide (MeBr) has been a standard practice for several California high value crops such as strawberry, sweet potato, and certified nursery stock, common practice for replant of several tree and vine crops, and has also been widely used for pepper, melon, tomato, lettuce, and carrot production. Methyl bromide has been determined to be an ozone depleter, and thus is being phased out under the international Montreal Protocol. USDA- ARS invests about $16 million per year in research related to MeBr alternatives - approximately 30% of that effort is located in California (Fresno, Salinas, Davis, and Riverside). Combinations of alternative fumigants (Telone, Chloropicrin, Iodomethane), improved application methods (drip-irrigation application), and beneficial cultural practices (fallowing) have been shown to maintain yields of several crops nearly as good as those with MeBr. However, there is no drop-in replacement. The cost and management requirements of most alternatives will be higher than with MeBr. Most fumigant alternatives are in jeopardy of regulatory restrictions, so we cannot depend completely on one chemical replacement. We must continue to work towards diagnosing, understanding, and targeting specific pathogens and problems, improving germplasm resistance, and improving our understanding of soil biology. Technical Abstract: Preplant soil fumigation with methyl bromide (MeBr) has been a standard practice for several California high value crops such as strawberry, sweet potato, and certified nursery stock, common practice for replant of several tree and vine crops, and has also been widely used for pepper, melon, tomato, lettuce, and carrot production. Methyl bromide has been determined to be an ozone depleter, and thus is being phased out under the international Montreal Protocol. USDA- ARS invests about $16 million per year in research related to MeBr alternatives - approximately 30% of that effort is located in California (Fresno, Salinas, Davis, and Riverside). Combinations of alternative fumigants (Telone, Chloropicrin, Iodomethane), improved application methods (drip-irrigation application), and beneficial cultural practices (fallowing) have been shown to maintain yields of several crops nearly as good as those with MeBr. However, there is no drop-in replacement. The cost and management requirements of most alternatives will be higher than with MeBr. Most fumigant alternatives are in jeopardy of regulatory restrictions, so we cannot depend completely on one chemical replacement. We must continue to work towards diagnosing, understanding, and targeting specific pathogens and problems, improving germplasm resistance, and improving our understanding of soil biology. |
