Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2011
Publication Date: 4/7/2011
Publication URL: http://dx.doi.10.1002/ps.2162
Citation: Gerik, J.S., Hanson, B. 2011. Drip Application of Methyl Bromide Alternative Chemicals for Control of Soilborne Pathogens and Weeds. Pest Management Science. 67: 1129-1133. Interpretive Summary: Several emerging chemicals have been proposed for use as preplant soil treatments as replacement for methyl bromide. These treatments were tested in two field trials as supplements for metam sodium treatments. The chemicals included 2-bromoethanol, dimethyl disulfide, furfural, propylene oxide, and sodium azide. In general the additional treatments improved the control of metam sodium of soilborne pathogens, but did not improve weed control in most cases. With increasing regulations of the methyl bromide alternatives, some of these emerging treatments may prove to be useful tool for growers of high value crops such as cut flowers.
Technical Abstract: BACKGROUND: Producers of several high value crops in California have traditionally used preplant soil fumigation with methyl bromide/chloropicrin. Although methyl bromide has been phased out since 2005, several crop industries, including cut flower producers, have continued methyl bromide use under Critical Use Exemptions, a provision of the Montreal Protocol. The present research was conducted to evaluate newer, emerging methyl bromide alternative chemicals. RESULTS: Two field trials were conducted to test several emerging chemicals in combination with metam sodium as replacements for methyl bromide. Emerging chemicals included 2-bromoethanol, dimethyl disulfide, furfural, propylene oxide, and sodium azide. Weed and pathogen populations were measured after chemical application and seed viability was assessed from weed seed previously buried in the plots. In the first trial, the emerging chemicals did not improve pest control compared to metam sodium alone. However, in the second trial several of these chemicals did improve the pest control performance of metam sodium. CONCLUSIONS: The emerging alternative chemicals alternative chemicals have the potential to provide better control of soilborne pathogens and weeds when used with metam sodium the metam sodium along. Registration of these materials could provide California growers with a broader choice of tools compared with the limited methyl bromide alternatives now available.