Methyl bromide (MeBr) was suspended in 2005 for agricultural use in the U.S. with the exception of yearly critical exemptions. Although the 2008 approved critical use exemptions allow 4813.5 metric tonnes of MeBr to be used in the U.S. (Perez-Sullivan, 2007), the need for an efficient, low-cost alternative still exists. The main aim of this study was to compare the efficacy of three colored films (black virtually impermeable film (VIF), metallized polyethylene (PE), and blue PE) with better distribution of the three biologically active compounds (Z)- and (E)-1,3-D and CP in field beds after chisel injection of Telone C35. It is recognized that VIF is a better barrier than metallized PE film which is better than blue PE for reducing volatilization of Telone C35, an alternative fumigant to MeBr, into the atmosphere. Maintaining appropriate concentration of the three biologically active compounds in the root zone for an adequate period of time after fumigation is essential for effective pest-pathogen management. It was demonstrated that carbonating Telone C35 provided better distribution; hence, it should enable a lower application rate to be as effective as high rate application by N2. Our results also indicated that carbonated Telone C35 initially penetrated deeper than non-carbonated Telone C35. Although this was beneficial by inhibiting re-infestation by deep dwelling nematodes, it may be problematic for areas with shallow water tables. The eventual goal is to link the three plastic covers and carbonation versus non-carbonation with fumigation efficacy. It is anticipated that those plastic films having higher capacity to retain a fumigant in the root zone such as black VIF and metallized PE combined with better distribution of the fumigant should provide greater efficacy for the fumigant even at reduced rate of application. METHODS Field site, fumigant, and plastic mulches. The field site was located at the Plant Science Research and Education Unit of the University of Florida in Citra about 35 km south of Gainesville, Florida. Soil at the site was classified as Arredondo fine sand. Analytical grade (Z) - and (E)-1,3-dichloropropene (1,3-D) and chloropicrin (CP) with greater than 99% purity plus Telone C35 (about 65% 1,3-D and 35% CP) were provided by Dow AgroSciences (Indianapolis, IN). Methyl Bromide (53%) mixed with chloropicrin (47%) was obtained from Great Lakes Chemical Corp. (West Lafayette, IN). Two colored high density PE (blue and metallized) with 0.033mm thickness and black VIF with 0.035mm thickness were used. Plots and fumigant treatment. Prior to fumigation, raised beds (0.90 m wide and 11 m long) were formed. These beds were injected with Telone C35 by three conventional sweptback chisels at 30 cm apart to 30 cm depth at rates of 327 or 245 liters/ha and immediately covered with one of the three plastic mulches. The 327 liters/ha as full rate and 245 liters/ha as three- quarter rate were applied using N2. Other beds received 245 liters/ha using CO2 as propellant/dispersant. Prior to application, the Telone C35 dispersed by CO2 was carbonated for