ABSTRACT
The intensity of emitted energy as the secretion is accumulating, increased up to a peak after 2 weeks in April, and decreased to zero at the end of April when the bud scale dropped and the young leaf was opening. At the beginning of May the leaves are unrolled from the buds. The secretory function serves for the defence of the primordial leaf from damage factors such as pests and late frosts. In the bud secretions phenolic compounds, mainly flavonoids and esters of aromatic acids as well as terpenoids prevail (Wollenweber et al., 1987; 1991; Roshchina and
