Dormancy: Difference between revisions

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 ==

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.

== 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.

== 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.

@@ 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 ==
-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.
 == 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.
 == 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.