The 2009 ASHS Annual Conference

Raspberry nurseries use preplant soil fumigation with methyl bromide:chloropicrin (mb:pic) to produce disease- and nematode-free plants.  The use of methyl bromide has been largely phased out, and exemptions for continued use are becoming more difficult to obtain.  Successful alternatives to mb:pic must provide full control of plant-parasitic nematodes, Agrobacterium tumefasciens, and Phytophthora rubi.  In trials conducted over two years mb:pic and alternative fumigants were evaluated, including: Midas^® (Methyl Iodide:cloropicrin), Telone^® C-35 and InLine^® (Telone:cloropicrin), solarization and a solarization + Inline^® combination.  Midas^® applied at 350 lb/A under a conventional (HDPE) tarp consistently provided excellent control of all weeds and pathogens.  Reduced (175 lb/A) rates of Midas^® were less effective than full rates.  Use of a Virtually Impermeable Film (VIF) tarp enhanced the efficacy of Midas^® applied at the reduced rate, and also enhanced efficacy of Telone^® C-35.  All of the treatments except for solarization controlled root lesion nematode (Pratylenchus penetrans), and all of the treatments evaluated enhanced marketable yield of nursery plants.