Determination of the Time of Onset of Rest in Spur and Shoot Buds of Apricot1

Abstract

Apricot shoots were defoliated and spurs were decapitated and defoliated on successive dates to determine the onset of rest in specific axillary buds. While the spurs were still growing and the leaves expanding decapitation alone would induce axillary bud growth. Later, when the spurs and leaves stopped growing both decapitation and defoliation were necessary to induce axillary bud growth. Eventually when the onset of rest occurred both decapitation and defoliation would not induce bud growth. Decapitation alone was enough to induce bud growth of terminal shoots. After the onset of rest decapitation and defoliation would not induce bud growth in the terminal shoot buds.