Abstract
The treatment of buds of Kyoto and Pione (V. labrusca L.×V. vinifera L.) with ammonium nitrate and/or calcium cyanamide hastened the sprouting by 13 to 15 days. This hastening was induced within two days after treatment with the chemicals. Treatment with the chemicals slightly increased the nitrogen contents of the buds. In Delaware (V. labrusca L.×V. aestivalis×V. vinifera L.) ,hastening of sprouting by 5 to 6 days with ammonium nitrate treatment was also observed, particularly from the fifth to the seventh bud although this effect differed depending on the sites of chemical treatment. Using ^15N-labeled ammonium nitrate, a considerable incorporation of ^15N was transported from the site of treatment to other sits in the buds and later to the newly grown leaves.
