ARS | Publication request: Evaluation of Reduced Methyl Bromide Rates and Alternative Fumigants in Field Grown Perennial Crop Nurseries.

Submitted to: Proceedings of International Research Conference on Methyl Bromide Alternatives
Publication Type: Abstract
Publication Acceptance Date: September 1, 2006
Publication Date: November 6, 2006
Citation: Hanson, B.D., Gerik, J.S., Schneider, S.M. 2006. Evaluation of Reduced Methyl Bromide Rates and Alternative Fumigants in Field Grown Perennial Crop Nurseries. Proceedings of International Research Conference on Methyl Bromide Alternatives, pgs. 126-1 - 126-4, Orlando, Florida, 2006.

Technical Abstract: Preplant fumigation with methyl bromide (MeBr) has commonly been used in field grown ornamental crops to provide broad-spectrum control of plant parasitic nematodes, soil-borne disease pathogens, and weed propagules. In California field nursery production, nematode-free certification requires a minimum of 300 lb/A MeBr in sandy soils or 400 lb/A in clay loam soils (33.6 or 44.8 g/m2). Many producers use a standard preplant fumigation treatment of 350 lbs/A (39 g/m2 MeBr) of the 98:2 MeBr:chloropicrin (PIC) formulation. MBTOC standard presumptions for recent evaluations of critical use nominations (CUN) suggest that reduced rates of 26 g/m2 for nutsedge and 20 g/m2 for pathogens and other weeds should be effective where low permeability barrier films (LPBF, ie VIF) are not available. Where LPBF is available, MBTOC standard presumptions suggest that MeBr rates of 17.5 and 15 g/m2 should provide effective control of nutsedge and pathogens, respectively. Currently, California regulatory agencies do not permit use of low permeability barrier films in soil fumigation and relatively little research has been done under local conditions to determine the efficacy of reduced MeBr rates for control of nematodes, pathogens, and weeds under local conditions. In this on-going research, preliminary data suggests that, on the weeds and pathogens present, reduced MeBr rates provide similar control to the standard treatment.