Fumigant distribution in forest nursery soils under water seal and plastic film after application of dazomet, metam-sodium and chloropicrin.
Authors:
Wang, D. Fraedrich, S.W. Juzwik, J. Spokas, K. Zhang, Y. Koskinen, W.C. USDA, FS
Source:
Pest management science. 2006 Mar., v. 62, issue 3, p. 263-273.
NALT Subjects:
forest nurseries crop management forest soils soil-borne diseases plant pathogenic fungi plant pathogenic bacteria plant viruses disease control soil fumigation fungicides pesticides dazomet metam chloropicrin application rate plastic film weed control herbicides plant parasitic nematodes nematode control Wisconsin Georgia
Other Subjects:
water seal covers
Issue Date:
Mar-2006
Abstract:
Adequate concentration, exposure time and distribution uniformity of activated fumigant gases are prerequisites for successful soil fumigation. Field experiments were conducted to evaluate gas phase distributions of methyl isothiocyanate (MITC) and chloropicrin (CP) in two forest-tree nurseries. Concentrations of MITC and CP in soil air were measured from replicated microplots that received dazomet, metam-sodium and CP. Half of the plots were covered with high-density polyethylene tarp immediately after fumigation; the other half were not covered but received daily sprinkler irrigation for 1 week to create and maintain a water seal. The magnitude of MITC concentrations was similar between nurseries for metam-sodium in both tarp and water seal treatments and for dazomet in the tarp treatment. Consistently greater MITC and CP concentrations were found in the upper 30 cm of soil in the tarped plots compared with the water-sealed plots. Despite potential environmental and economic benefits with the water seal method, tarp covers were more reliable for achieving and maintaining higher MITC and CP concentrations and less prone to variations due to irrigation/rain, soil bulk density and other environmental conditions.
