Wheat (Triticum aestivum L. ‘Holley’) was grown for 14 days in 0.5 strength Hoagland and Arnon's complete mineral nutrient solution containing 0. 15.6, 31.25, 62.5, 125.0, or 250.0 ppbw EPTC (S-ethyl dipropylthiocarbamate). Gibberellic acid (GA) content, as measured by gas-liquid chromatography, was decreased 96.4% by 125.0 ppbw EPTC. When 0.05 μCi mevalonic acid-2-14C-(MVA-2-14C) (DBED salt) (0.15 mCi/mg MVA) was added to the nutrient solution, incorporation of MVA-2-14C into total kaurenoids was decreased 90% by 250 ppbw EPTC. Metabolism of kaurene was reduced by 250 ppbw EPTC with resultant 3-fold accumulations of kaurene.