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United States Department of Agriculture

Agricultural Research Service

Title: Fumigant Concentration Distribution in Forest Nursery Soils under Water Seal and Plastic Film after Application of Dazomet, Metam Sodium, and Chloropicrin

Authors
item Wang, D - UNIV OF MINNESOTA
item Fraedrich, S - USDA FOREST SERVICE
item Juzwik, J - USDA FOREST SERVICE
item Spokas, K - UNIV OF MINNESOTA
item Zhang, Y - UNIV OF MINNESOTA
item Koskinen, William

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 15, 2005
Publication Date: February 15, 2006
Citation: Wang, D., Fraedrich, S.W., Juzwik, J., Spokas, K., Zhang, Y., Koskinen, W.C. 2006. Fumigant concentration distribution in forest nursery soils under water seal and plastic film after application of dazomet, metam sodium, and chloropicrin. Pest Management Science. 62:263-273.

Interpretive Summary: Production of tree seedlings in forest nurseries has relied on soil fumigation with methyl bromide (MeBr) to control soilborne plant pathogens, weeds, parasitic nematodes and insects. Since the announcement of the scheduled MeBr phase-out, a number of nurseries throughout the United States have participated in research programs on MeBr alternatives. There does not appear to be any information on the environmental fate and emission of these potential alternative fumigants when applied in forest tree nurseries. The objective of this study was to evaluate atmospheric emissions of fumigants MITC and CP for four alternative fumigation methods as combinations of two fumigants and two surface cover treatments. Consistently higher MITC and CP concentrations were found in the top 30-cm soil under the tarp than water seal covers. Despite potential environmental and economic benefits with the water seal method, the tarp cover appeared to be more reliable in achieving and maintaining higher MITC and CP concentrations than the water seal cover, and less prone to variations in irrigation/rain, soil bulk density, and environmental conditions. These data will help scientists determine effective replacements for MeBr by providing important information on MITC and CP emissions during soil fumigation management in forest tree nurseries.

Technical Abstract: Adequate concentration exposure time and distribution uniformity are prerequisites for a successful soil fumigation. Field experiments were conducted to evaluate spatial and temporal distribution characteristics of methyl isothiocyanate (MITC) and chloropicrin (CP) in two forest tree nurseries. Soil air concentrations of MITC and CP were measured from replicated microplots received dazomet, metam sodium, and CP. Half of the plots were covered with a high density polyethylene tarp immediately after fumigation; the other half was not covered but received daily sprinkler irrigation for one week to create a water seal. Results showed similar (in magnitude) MITC concentrations from either dazomet or metam sodium applications. Consistently higher MITC and CP concentrations were found in the top 30-cm soil under the tarp than water seal covers. Despite potential environmental and economic benefits with the water seal method, the tarp cover appeared to be more reliable in achieving and maintaining higher MITC and CP concentrations than the water seal cover, and less prone to variations in irrigation/rain, soil bulk density, and environmental conditions.

Last Modified: 11/28/2014