Nineteen-day-old soybean [Glycine max (L.) Merr. cv. A 2] plants were treated with soil-applied paclobutrazol, an antigibberellin growth inhibitor, at the rate of 125 µg per 10 cm pot. The plants were then grown for 14 days under a 14 hr photoperiod after which they were transferred to the dark for senescence induction