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Decomposition of Phenoxyalkyl Carboxylic Acids
Author(s) -
Burger K.,
MacRae I. C.,
Alexander M.
Publication year - 1962
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1962.03615995002600030016x
Subject(s) - carboxylic acid , chemistry , decomposition , persistence (discontinuity) , chlorine , phytotoxicity , bioassay , acetic acid , organic chemistry , ring (chemistry) , amino acid , agronomy , biology , biochemistry , geotechnical engineering , engineering , genetics
The persistence of phenoxyalkyl carboxylic acids in soil was measured by a bioassay technique using alfalfa seedlings. Acetic, alpha‐propionic and alpha‐ and gammabutyric acid derivatives were toxic when applied to soil planted to alfalfa whereas the beta‐propionic acid derivatives showed no inhibition of the test plant. All 3,4‐dichloro‐ and 2,4,5‐trichlorophenoxyalkyl carboxylic acids exhibited prolonged persistence in soil. The duration of phytotoxicity in soil receiving 4‐chloro‐, 2,4‐dichloro‐ and 2‐methyl‐4‐chlorophenoxyalkyl carboxylic acids was governed by the type and linkage of the aliphatic side chain. A Flavobacterium sp. active in the degradation of phenoxybutyric acids was isolated. The bacterium metabolized only phenoxybutyric acids having no meta chlorine on the aromatic ring. In the decomposition, the organic chlorine was liberated and the aromatic ring cleaved. The results demonstrate that specific structural characteristics of these herbicide molecules govern persistence of the compounds in soil.