Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2005
Publication Date: N/A
Technical Abstract: Open field rose nurseries commonly use methyl bromide to fumigate the soil prior to planting in order to insure the production of plants that are free of soilborne pests and pathogens. Under the terms of the Montreal Protocol use of methyl bromide by developed countries was phased out as of January 1, 2005. Exceptions to the phase-out include approved Critical Uses and quarantine uses. Although the United States has obtained a Critical Use Exemption for field grown nurseries for 2005 and 2006, growers of these crops need alternatives to methyl bromide. In a field trial initiated in fall 2001, fumigants were applied either through standard shank-injection equipment or as emulsifiable compounds through drip irrigation equipment. Treatments included methyl bromide; 1,3-dichloropropene (1,3-D), alone and in combination with chloropicrin (Pic); iodomethane (IM) + chloropicrin; chloropicrin alone; and metam sodium. At the time of planting (December 2001), nematodes were detected in several treatments, most notably the untreated control; untarped 1,3-D + pic; and pic alone, especially at deeper soil depths. In spring 2003, weed control was greatest in the methyl bromide and tarped 1,3-D + pic treated plots. At harvest in December 2003, rootknot nematode was detected in the roots of plants grown in untreated plots and plots treated with untarped 1,3-D + pic, metam sodium, and chloropicrin alone. These results would not be acceptable in a nursery crop. Alternative fumigants offer promise as alternatives to methyl bromide for open field nursery production systems. Additional field trials under commercial conditions and over a wider range of soil conditions are needed to further evaluate shank-injected and drip-applied 1,3-D + pic and IM + pic as alternatives to methyl bromide for open field rose nurseries.