Salicylic acid (SA) inhibited germination of cocklebur (Xanthium pennsylvanicum
Wlr), lower seeds, which are completely after-ripened and nondormant. SA also
inhibited ethylene production during a pre-germination period of the seeds. Exogenous ethylene overcame the inhibtion of the seed germination by SA. Moreover, SA reduced respiration in pre-germinating whole seeds as well as excised axial tissues.S A was suggested to inhibit more severely cyanide-sensitive respiration than cyanideresistant respiration. The inhibition of both ethylene production and respiration by S A was thought to be the cause of prevention of cocklebur seed germination . The mechanism of the action of SA is discussed in the inhibition of cockelbur seed germination