Soil persistence of dimethyl disulfide combined with chloropicrin after repeated applications

Applying pre-plant soil fumigation is a commonly used practice in plasticulture production systems to control some weed species, bacteria, and pathogenic fungi that can cause damage to high value crops such as cut flowers and vegetables. Since the phasing out of methyl bromide, growers have been seeking an alternative that has similar broad spectrum efficacy. Dimethyl disulfide (DMDS) alone or combined with chloropicrin (Pic) has proven to be effective against pathogens and has the potential to become a widely used pre-plant soil fumigant. The results show that the addition of Pic significantly increases the soil persistence of DMDS when compared to pure DMDS under totally impermeable film (TIF). Dissipation of pure DMDS during the fall application was quicker during the spring application. The dissipation curve exhibited by DMDS:Pic in the fall was not typical of this mixture. It is unclear if this trend is a result of the sequential applications.