Important fungi that decay wood protucts were "inoculated" into nonpressure-treated southern pine timbers as vapor-sensing agents to evaluate the effect of wrapping on the movement and persistence of fungitoxic concentrations of chloropicrin, Vapam, and Vanicide TH in the timbers. Fumigant movement and persistence in the timbers was enhanced by wrapping the timbers in polyethylene after fumigation. Chloropicrin moved fastest and exhibited the highest fungitoxicity at the greatest distance from the treatment center (CL). Almost 100% of fungal cultures implanted into chloropicrin-treated timbers died up to 1.22 m (4 ft) from CL by 4 months after treatment. Vapam was the next best with good fungitoxicity at 0.61 m (2 ft) from CL within 4 months; most cultures were killed at 1.22 m from CL by 8 months. Vanicide TH killed most cultures at 0.30 m (1 ft) from CL by 4 months and at 0.61 m from CL by 8 months. Fungitoxicity of Vanicide TH at 1.22 m from CL was variable. By 12 months, fungitoxicity decreased for all treatments, although chloropicrin and Vapam continued to kill all cultures at 0.30 m from CL. Bioassay of cores extracted from chloropicrin- and Vapam-treated timbers at 12 and 24 months exhibited a fungistatic effect at 0 30, 0.61, and 1.22 m from CL. Cores from Vanicide TH-treated timbers exhibited little fungistatic effect at 12 months but good fungistatic effect up to 0.61 m from CL at 24 months.

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