Dormancy: Difference between revisions

Created page with "'''Dormancy''' is a physiological resting phase in the annual growth cycle of the grapevine, during which visible growth ceases and metabolic activity is greatly reduced. From a viticultural and wine perspective, dormancy is essential for vine survival, carbohydrate balance and the regulation of subsequent growth stages, directly influencing budbreak, yield potential and long-term vineyard performance.<ref>Robinson (ed.), ''The Oxford Companion to Wine'', Oxford..."
 
m CodexWarrior: canonicalise ISBN refs
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
'''Dormancy''' is a physiological resting phase in the annual growth cycle of the [[grapevine]], during which visible growth ceases and metabolic activity is greatly reduced. From a viticultural and wine perspective, dormancy is essential for vine survival, carbohydrate balance and the regulation of subsequent growth stages, directly influencing [[budbreak]], yield potential and long-term vineyard performance.<ref>Robinson (ed.), ''The Oxford Companion to Wine'', Oxford University Press, 2015, ISBN 9780198705383.</ref>
'''Dormancy''' is a physiological resting phase in the annual growth cycle of the [[grapevine]], during which visible growth ceases and metabolic activity is greatly reduced. From a viticultural and wine perspective, dormancy is essential for vine survival, carbohydrate balance and the regulation of subsequent growth stages, directly influencing [[budbreak]], yield potential and long-term vineyard performance.<ref>Jancis Robinson, ''Oxford Companion to Wine'', Oxford University Press, 17 Sept. 2015. ISBN 9780198705383.</ref>


== Definition and phases ==
== Definition and phases ==
Dormancy in grapevines occurs after [[leaf fall]] in autumn and extends through winter until the resumption of growth in spring. It is commonly divided into two overlapping phases: endodormancy and ecodormancy. Endodormancy is internally regulated within the bud and cannot be broken even under favourable conditions, while ecodormancy is imposed by external environmental factors, primarily low temperature.<ref>Mullins, Bouquet & Williams, ''Biology of the Grapevine'', Cambridge University Press, 1992, ISBN 9780521305071.</ref>
Dormancy in grapevines occurs after [[leaf fall]] in autumn and extends through winter until the resumption of growth in spring. It is commonly divided into two overlapping phases: endodormancy and ecodormancy. Endodormancy is internally regulated within the bud and cannot be broken even under favourable conditions, while ecodormancy is imposed by external environmental factors, primarily low temperature.<ref>Michael G. Mullins, Alain Bouquet, Larry E. Williams, & 0 more, ''Biology of the Grapevine'', Cambridge University Press, July 30, 2007. ISBN 9780521038676.</ref>


The transition from dormancy to active growth requires exposure to sufficient winter chilling, followed by warmer spring temperatures that trigger [[budbreak]].
The transition from dormancy to active growth requires exposure to sufficient winter chilling, followed by warmer spring temperatures that trigger budbreak.


== Physiological role ==
== Physiological role ==
During dormancy, the vine reallocates and conserves energy. [[Carbohydrate]] reserves accumulated during the growing season are stored in the trunk, roots and perennial wood, providing the primary energy source for early spring growth before photosynthesis resumes.<ref>Ribéreau-Gayon et al., ''Handbook of Enology, Volume 1'', Wiley, 2006, ISBN 9780470010372.</ref>
During dormancy, the vine reallocates and conserves energy. [[Carbohydrate]] reserves accumulated during the growing season are stored in the trunk, roots and perennial wood, providing the primary energy source for early spring growth before photosynthesis resumes.<ref>Pascal Ribéreau-Gayon, Yves Glories, Alain Maujean, Denis Dubourdieu, & 1 more, ''Handbook of Enology, Volume 2: The Chemistry of Wine - Stabilization and Treatments'', Wiley, 31 Mar. 2006. ISBN 9780470010372.</ref>


Bud tissues undergo physiological changes that increase cold hardiness, enabling vines to survive winter conditions. Proper dormancy is therefore critical for vine longevity and resilience.
Bud tissues undergo physiological changes that increase cold hardiness, enabling vines to survive winter conditions. Proper dormancy is therefore critical for vine longevity and resilience.


== Viticultural significance ==
== Viticultural significance ==
Dormancy is the period during which key vineyard operations take place, most notably [[pruning]]. Pruning timing during dormancy influences vine vigour, yield balance and susceptibility to spring frost. In cooler climates, delayed pruning is sometimes used to postpone budbreak and reduce frost risk.<ref>Keller, ''The Science of Grapevines'', Academic Press, 2015, ISBN 9780124199873.</ref>
Dormancy is the period during which key vineyard operations take place, most notably [[pruning]]. [[Pruning]] timing during dormancy influences vine vigour, yield balance and susceptibility to spring frost. In cooler climates, delayed pruning is sometimes used to postpone budbreak and reduce frost risk.<ref>Markus Keller, ''The Science of Grapevines: Anatomy and Physiology'', Academic Press Inc, 19 Jan. 2015. ISBN 9780124199873.</ref>


Dormancy also affects the uniformity of budburst. Inadequate chilling can lead to irregular or delayed budbreak, resulting in uneven shoot development and ripening.
Dormancy also affects the uniformity of budburst. Inadequate chilling can lead to irregular or delayed budbreak, resulting in uneven shoot development and ripening.