Scanning electron-microscopy of abscission-zone surfaces of Valencia-orange fruit.

The scanning electron-microscope was used to obtain a more adequate view of the separation surfaces exposed when the stem was pulled from the fruit of Valencia orange. Separations were made at 0, 24 and 48 h after ethylene treatment of the fruit. The most noticeable differences are the lessened amount of tearing in proximal vascular bundles at 48 h and decreased rupture of distal parenchyma cells first observed at 24 h.