The Inhibition of Flowering by Water Stress

Abstract

Plants of Lolium temulentum L., a single.cycle, long.day plant, and Pharbitis nil Ohois. cv. Violet, a single·cycle, short-day plant, were subjected to osmotic stress during the inductive cycle. An osmotic potential of-IS atm (using poly. ethylene glycol, mol. wt. 4000) during the 24·hr exposure to light completely prevented flowering in L. temulentum. Similarly, -6 atm osmotic potential during the 16-hr dark cycle suppressed flowering in P. nil. Water stress during induction, achieved by withholding water to soil-grown plants, also prevented flower induction in Xanthium strumarium L.