Mylone (3,5-dimethyl tetrahydro-1,3,5,2H thiadiazine-2-thione) 
Activation or degradation of mylone in soil was dependent on moisture 
or free water and was a function of time and temperature. Formaldehyde 
was the first breakdown product and appeared within 15 minutes at room 
temperature. Methylamino methyldithiocarbamate appeared next and in 
turn formed CH3NH,, methyl isothiocyanate, and hydrogen sulfide. Mono- 
methyl amine and hydrogen sulfide reacted with formaldehyde to form 
methyl amino methanol, dimethyl amino methane, and 1,3,5-trithio- 
cyclohexane. Eventually this proceeded to CO,, NH3, SO9, and H90. The 
methyl isothiocyanate reacted with H,0 to yield COj, H)S, and CH3NH, 
(McKenzie, 1957; Torgeson et al., 1957; Munnecke, 1963; Munnecke and 
Martin, 1964). Methyl isothiocyanate may also react with ammonia, 
amines or sulfhydryls if present. 
Methyl isothiocyanate release was found to be a first order 
reaction and varied directly with temperature and moisture; increased 
with soil pH over the range of 2.3 to 6.5 but fell off at values up 
to pH 7.7; decreased with increased clay or peat content; not 
dependent upon soil organisms (Munnecke, 1963). 
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