This study investigates whether, and how, 1-aminocyclopropane-1-carboxylic acid (ACC) is concerned in flower bud abscission of pistachio (Pistacia vera L.). Abscission was studied about the activation of the abscission zone, located between shoot and flower bud, from Uzun pistachio cultivar where the abscission profiles and the scanning electron micrographs pictorial differences in the abscission program, under natural conditions of flower bud. |