Stereoselective degradation of fungicide triadimenol in cucumber plants.

The stereoselective degradation of triadimenol in different cucumber plant tissues (root, stem, leaf, and fruit) has been investigated. Rac-triadimenol was applied to cucumber plants by root irrigation mode under field conditions. The degradation kinetics and the enantiomer fraction were determined by normal-phase high-performance liquid chromatography with diode array detector and on-line optical rotatory dispersion detector on Chiralpak AS-H column. It has been shown that the degradation of triadimenol in cucumber plants was stereoselective under field conditions. The results indicated that RS enantiomer was degraded faster than SR enantiomer, and SS enantiomer was degraded faster than RR enantiomer, which resulted in plants enriched with SR and RR enantiomers. Furthermore, it was found that leaf was the dominating location for triadimenol enantiomer accumulation and stereoselective degradation, comparing with the root, stem, and fruit tissue. 2009 Wiley-Liss, Inc.