Chloropicrin can be used at low concentrations as an odorant in conjunction with methyl

bromide for detection of escaping fumes of methyl bromide. Chloropicrin is an irritant to the

eyes and respiratory tract and allows detection prior to inhalation of substantial quantities of the

chemical. It has been recommended that chloropicrin (not less than 2%) be used in conjunction

with methyl bromide for detection of atmospheric methyl bromide (Noling, 1993b).


Application of Methyl Bromide as a Soil Fumigant

 In preparing a field for subsequent use of methyl bromide, plowing and disking should

be performed to turn under old crop residue in order to reduce detrimental soil organisms and

to allow for decomposition of crop residue. Disking ensures that large clods of soil are broken

down and aids in leveling the field for ease of future activities such as bed formation. Bed

formation can be done using a disc hiller or bedding disc. The soil should be analyzed for pH

adjustment and fertilizer requirements (Hochmuth, 1989a). Bed widths generally range from 24

to 36 inches depending on the crop and irrigation type. The height of the bed is approximately

8 inches. The number of beds between irrigation-drainage furrows varies from one to four,

depending on the soil type and drainage capabilities of the land.

 Methyl bromide for preplant fumigation is sold in pressurized gas cylinders, in various

formulations with chloropicrin. The chemical is delivered via a positive pressure system using

nitrogen gas for pressure. Methyl bromide is injected into the soil as a liquid to a depth of 8

to 12 inches using tractor drawn chisels or shanks spaced no more than 12 inches apart. The

liquid then vaporizes and diffuses through the soil from the point of injection. One or more

shanks per bed may be required depending on the width of the bed. Rates of application can

range from 100 pounds to over 400 pounds of active ingredient per acre depending on the