Fumigant pesticide combinations with a high potential to replace methyl bromide/chloropicrin (MB/Pic) for management of a multi-pest complex were tested as preplant treatments under two different types of plastic mulch (high density polyethylene film, HDPE, and virtually impermeable film, VIF) in a commercial floricultural system in California. Field studies were initiated in Moss Landing in 2006. Shank-applied fumigant treatments were MB/Pic, Pic, Telone C35, and Midas at 350, 300, 400, and 300 lb/A, respectively. Drip-applied fumigant treatments were MB/Pic, Pic, InLine, and Midas at 200, 200, 300 and 200 lb/A, respectively. Metam potassium was applied sequentially at 35 gal/A to half of the drip-applied treatments and the untreated control 6 days past the first fumigant application. Mesh bags containing pathogen, weed seed and flower bulb samples were installed at 15 cm soil depth before fumigation and removed 1 to 2 weeks after fumigation. Mesh bags were analyzed for survival of weed seeds, flower bulbs, and pathogens following standard procedures. Calla lily (Zantedeschia sp.), were planted at the entire plot area 3 weeks after fumigation, and conventional production practices and pest management were followed. Densities of native weed populations and plant growth parameters were evaluated at regular intervals during the season. Flower stems and bulbs will be harvested, counted, and bulbs will be graded according to size (circumference) and weight for quality evaluation. Relative to MB/Pic drip-applied alternative fumigants showed similar or better control of Verticillium dahliae, Fusarium oxysporum, Phytophthora cactorum and Pythium spp. Sequential metam potassium application significantly increased control of key pathogens by ≥ 40 and 90% in fumigated and untreated soils, respectively. Relative to shank application, drip applied fumigants showed similar or better control of soil-borne pathogens, with exception of Rhizoctonia sp. Flower stem and bulb yield and quality data will be presented.