labeled simazine-c!4, it was found that field corn (Zea mays) 
produced little (about 2%) cl4o, (Davis et al., 1959a, b; Foy, 
1960) whereas in sweet corn the rate of decomposition to cl4o,, 
was high (Ragab and McCollum, 1961). 
Other studies have demonstrated the formation in plants of 
2-hydroxy-4, 6-bis(ethylamino) -S-triazine from simazine (Roth, 
1957; Montgomery and Freed, 1959, 1960, 1961, 1964; Gysin, 1960a, 
b, 1962; Anon, 1961; Castelfranco et al., 196la, b; Hamilton and 
Moreland, 1962, Funderburk and Davis, 1963; Plaisted and Thornton, 
1964). 
A cyclic hydroxamate was postulated as the responsible agent 
in the metabolism of triazines by plants and a mechanism was pro- 
posed. This was confirmed with the isolation of 2,4-dihydroxy- 
7-methoxy-1,4-benzoxazin-3-one from Zea mays and the demonstration 
that it can convert simazine to its hydroxy analog (Roth and Knuesl1li, 
1961; Castelfranco et al., 196la, 1962; Hamilton et al., 1962). 
Studies have shown that many soil microorganisms metabolize 
simazine (Montgomery, 1958; Pochon et al., 1960; Guillemat et al., 
1960a, b; Ragab and McCollum, 1961; Kaufman et al., 1963; Farmer 
et al., 1965). One of the major metabolites has been identified as 
hydroxysimazine (Harris, 1965). The soil fungus Aspergillus fumi- 
gatus, however, attacked the side chain only of simazine (Kaufman 
et al., 1965). Degradation proceded via dealkylation, deamination, 
or both, and hydroxysimazine was not an intermediate. A major 
metabolite has been identified as 2-chloro-4-amino-6-ethylamino- 
S-triazine (Kearney et al., 1965). 
161 
