Cladoptosis

Cladoptosis (Greek: clados - a branch, ptosis - falling; it is sometimes pronounced with the p silent) refers to the phenomenon in botany of the regular shedding of branches. It is the counterpart for branches of the familiar process of regular leaf shedding by deciduous trees. As in leaf shedding, an abscission layer forms and the branch is shed cleanly.

Read more about Cladoptosis:  Functions of Cladoptosis