Metabolism of triadimefon in barley shoots

Barley plants grown in a greenhouse were treated at growth stage 6 (during the stem extension, when the first node of the stem was visible at the base of the shoot) by spraying with [14C]triadimefon at a rate of 500 g of triadimefon ha−1, which is four times higher than is recommended. The aerial part of the plants was harvested and analysed, 66 days after treatment, at growth stage 10 (during the stem extension, when the sheath of the last leaf was completely grown out, and the ear was swollen but not yet visible). Free triadimefon and triadimenol (the mixture of both diastereoisomers of triadimenol) accounted for 9.7 and 20.3%, respectively, of the total radioactivity incorporated into the plant; their concentrations in the plants were 1.00 and 2.10 mg of the respective products kg−1 fresh weight. Conjugated triadimenol and 4‐chlorophenol, respectively, accounted for 8.0 and 35.1% of the total radioactivity in the plant, and their concentrations in the plant were 0.80 and 1.58 mg of the respective non‐conjugated products kg−1 fresh weight. Only 13% (the bound residue) of the total radioactivity was insoluble in acetone+water (10+3 by volume).