Residue studies using 14C-benazolin, with special reference to its persistence on foliage under glasshouse conditions
Article first published online: 5 MAY 2006
Copyright © 1969 John Wiley & Sons, Ltd
Journal of the Science of Food and Agriculture
Volume 20, Issue 3, pages 185–190, March 1969
How to Cite
Lewis, D. K. (1969), Residue studies using 14C-benazolin, with special reference to its persistence on foliage under glasshouse conditions. J. Sci. Food Agric., 20: 185–190. doi: 10.1002/jsfa.2740200312
- Issue published online: 5 MAY 2006
- Article first published online: 5 MAY 2006
- Manuscript Accepted: 28 NOV 1968
- Manuscript Received: 27 SEP 1968
14C-Benazolin (4-chloro-2-oxobenzothiazolin-3-ylacetic acid), labelled in the carboxyl carbon, was applied to barley and other cereals, ryegrass, clover, and chickweed, and the loss of radioactivity was studied. Radioactivity was readily removed from the leaves by washing with water soon after application, but, generally, only 40 % or less of the applied dose was recoverable in this way after 3 days. the total level of radioactivity was reduced to approximately 5% of that applied to the plants 4 weeks after application in the case of clover and ryegrass, and 8 weeks after application to barley. Analysis of all field-grown cereals showed no detectable residue in grain or straw at the time of harvest, using a method capable of detecting 0.04 ppm.
Autoradiography of thin-layer co-chromatograms of the extracts showed that most of the radioactivity was present as unchanged benazolin.
There appears to be no simple relationship between the concentration of benazolin accumulating in the plant and herbicidal activity, as judged by parallel experiments on barley and ryegrass (resistant) and chickweed (susceptible species). It is concluded that the resistance cannot be related simply to an ability to exclude or metabolise 14C-benazolin.
Column percolation experiments showed that benazolin was readily removed from the soil by water.