Metabolism of Tordon Herbicide (4-Amino-3,5,6-trichloropicolinic Acid) in Cotton and Decomposition in Soil
Meikle, R. W.; Williams, E. A.; Redemann, C. T.
Journal of Agricultural and Food Chemistry 14(4): 384-387
ISSN/ISBN: 0021-8561 DOI: 10.1021/jf60146a015
In glasshouse experiments, 40 micro g of picloram-14C in 25 ml water per pot was applied to a sandy loam soil 21 days after sowing cotton. The rate of metabolism of picloram by the cotton plants and by soil microorganisms was measured from the amount of radioactive CO2 evolved. Soil containing living plant roots was shown to be significantly more active than bare soil in decomposing picloram even though the rate of metabolism by the cotton plants was very slow. After 14 days, no radioactive compounds other than picloram were detected in total plant extracts with hexane. On a total plant weight basis, the leaf and stem tissue of the cotton plant contained 95 % of the total radioactivity present and of this 3 % was associated with insoluble protein and could not be removed by extraction procedures.