Definition - What does Bud burst mean?
Bud burst refers to the period in early spring during which grapevines, which have been dormant through the winter, first begin to produce new shoots. During the bud burst phase, the vines are quite susceptible to frost damage. This makes it a particularly delicate time during the process of cultivating grapevines.
WineFrog explains Bud burst
During the winter, as the temperature begins to drop, grapevines go into a dormant state, dropping their leaves and producing brown scales that protect the plant from the harsh winter weather. As the temperature begins to warm again in spring, they emerge from dormancy to send forth new shoots. Small buds on the vine will now give rise to leaves and flowers.
Bud burst is brought about by changes in the air and soil temperature, although the optimal temperature for bud burst can vary between different varieties of grapes. Because of the role of soil temperature in the physiological signaling that causes the plant to emerge from dormancy, soil management is important to ensure that bud burst occurs at the right time. Well-drained, relatively stony soils are preferred over wetter soils with a higher clay content, particularly in cooler climates, as they warm up faster.