Chloropicrin Mitigation Proposal: Control of Resident and Bystander Acute Exposure from Soil 2013a.
Planting beds were prepared with a 6-foot center wheel spacing tractor (2-wheel drive Model 6615, John Deere, Moline, IL) and were fumigated with methyl bromide 80/20 formulation (80% methyl bromide, 20%
chloropicrin) at the rate of 283.5 kg/ ha.
The researchers anticipate that growers will likely end up using an assortment of biological control and chemical options--instead of relying on a few magic-bullet chemicals like methyl bromide paired with
chloropicrin.
Many began to rely more heavily on other, still allowable fumigants: they increased the percentage of
chloropicrin they used in combination with methyl bromide, or they switched to
chloropicrin alone or in combination with 1,3-D (Telone).
* Fumigants (37 entries, including
chloropicrin, methyl bromide, 1,3-dichloropropene, metam-sodium, metam-potassium, and sulfuryl fluoride)
As a result of this phaseout, which began in 2001, the use of alternative fumigants such as 1,3-dichloropropene (1,3-D) and
chloropicrin (trichloronitromethane) has increased (CDPR 2009).
The pesticides evaluated include
chloropicrin, chlorothalonil, chlorpyrifos, S,S,S-tributyl phosphorotrithioate, diazinon, 1,3-dichloropropene, dichlorvos (naled breakdown product), endosulfan, eptam, methidathion, methyl bromide, methyl isothiocyanate (MITC; metam sodium breakdown product), molinate, propargite, and simazine.
Fumigants other than methyl bromide, such as
chloropicrin, remain widely used in California strawberry production.
Standard Test Method TMS-003: Chlorination Disinfection By-products (Heloacetonitriles, Chloroketones,
Chloropicrin, Chloral Hydrate) in Water.
Recognition of the fungicidal properties of
chloropicrin and the enhanced efficacy achieved by addition of methyl bromide lifted this limitation and allowed for a dramatic expansion in the production of fresh strawberries in California.
Eleven pesticides with more than 1 million pounds per year of use in California had insufficient toxicologic and environmental data for hazard weighting (sulfur, petroleum oil, sodium chlorate, copper hydroxide, mineral oil, copper sulfate,
chloropicrin, petroleum distillates, sulfuryl fluoride, calcium hydroxide, and diuron).
Many perennial crop growers have adopted methyl bromide alternatives such as 1,3-dichloropropene (1,3-D) and
chloropicrin. These alternatives, however, are also highly regulated because of their toxicity and the emission of volatile organic compounds (VOCs), which degrade air quality by forming ground-level ozone.