Soil Mobility of Allyl Isothiocyanate and Chloropicrin as Influenced by Surfactants and Soil Texture

Abstract

Methyl bromide (MeBr) was identified as a stratospheric ozone depletory; therefore, the use of MeBr was phased out in the United States in 2005. Chloropicrin (CP) and allyl isothiocyanate (AITC) are MeBr replacements. A mixture of CP and AITC is commonly applied to broaden the pest control spectrum. These two fumigants have low soil mobility; however, their efficacy could be improved if their soil mobility were enhanced. This research was conducted to study the effects of surfactants applied at 5% (v/v) for CP mobility and AITC mobility in soils. Mobility of the CP/AITC mixture applied with a nonionic surfactant comprising oleic, linoleic, and palmitic acids (nonionic-1) and mobility of the CP/AITC mixture applied with a nonionic surfactant comprising C9 hydrocarbon aromatics and calcium alkylarylsuphonate (nonionic-2) were compared with mobility of the CP/AITC mixture applied without surfactants in three soils (Elder sandy loam, Chualar loam, and Blanco clay loam) during a laboratory study. Nonionic-1 surfactant increased the concentration of total leachate collected for AITC by five and CP by 11 compared with CP/AITC applied alone. Surfactants may influence the fumigant mobility in soil by affecting the sorption/desorption equilibrium. Our research suggested that increased AITC mobility and CP mobility in soil with the addition of adding nonionic-1 surfactant may be due to the adsorption behavior of the surfactant in the soil and the solubilizing capability of the surfactant with pesticides.

Sorghum cover crop and repeated soil fumigation for purple nutsedge management in tomato production

“…Nutsedge management with fumigants is desirable because it would reduce the need to apply herbicides in the crop and would prevent mulch punctures. Many alternative soil fumigants have been evaluated since the phase‐out of methyl bromide 19–24 . A number of fumigants including 1,3‐dichloropropene (1,3‐D), chloropicrin (Pic), allyl isothiocyanate, dimethyl disulfide (DMDS), and methyl isothiocyanate generators such as metam potassium have been registered for use in specialty crops 7, 25–29 .…”

“…Many alternative soil fumigants have been evaluated since the phase-out of methyl bromide. [19][20][21][22][23][24] A number of fumigants including 1,3-dichloropropene (1,3-D), chloropicrin (Pic), allyl isothiocyanate, dimethyl disulfide (DMDS), and methyl isothiocyanate generators such as metam potassium have been registered for use in specialty crops. 7,[25][26][27][28][29] However, application of a single product tends to only provide effective control of only one or two classes of pests.…”