Changes in Abscission Processes with Aging

Abstract

As leaves grow older they show increasing tend- encies for abscission. With aging there are changes in the substances which can regulate abscission, such as a decline in the auxin level (9, 15), increases in the amino acids More recently the physiological processes leading to bean leaf abscission have been separated into 2 successive stages (13) and the present study aimis to analyse the increasing tendencies for abscission as they may relate to the completion of the 2 successive stages.