Effect of delaying budburst on shoot development and yield of Vitis vinifera L. Chardonnay ‘Mendoza’ after a spring freeze event

Abstract

Background and Aims: Spring freeze events can result in substantial grapevine yield losses in many parts of the world. Understanding vine responses following early spring freeze events will aid in the development of decision support systems for vineyards damaged by freezing temperatures. Methods and Results: The date of budburst of spur‐pruned Chardonnay vines was manipulated by pruning time and/or the application of sodium alginate gel. A spring freeze event occurred at bud swell/woolly bud, killing 33% of the developing shoots. Treatments that delayed bud development expressed a lower incidence of freeze damage (as low as 3%). Where primary shoots had been killed, secondary shoots developed in their place. The yield from secondary shoots was 32% of that from primary shoots, with the majority of fruiting secondary shoots bearing only one bunch. Average bunch weight, number of berries per bunch and average berry weight of secondary shoots were comparable with those from primary shoots. Conclusions: The damage to primary shoots caused by early spring freeze events can be reduced by using treatments that delay bud development. Secondary shoots develop in response to death of the primary shoot, and although they have reduced fruitfulness, they can partially mitigate the potential yield losses associated with the death of primary shoots. Significance of the Study: The number and fruitfulness of secondary shoots that develop after a spring freeze event determine the extent of mitigation of yield losses associated with the death of primary shoots.

Late pruning impacts on chemical and sensory attributes of Shiraz wine

“…Warming has advanced the harvest and hastened ripening in recent decades, thus higher TSS in grapes are attained earlier and ahead of other relevant fruit attributes related to colour, flavour and aroma (Jones et al , Sadras et al , Sadras and Moran ). Late pruning has been used to reduce the risk of frost and improve fruitset in cool climate regions such as New Zealand (Friend and Trought , Friend et al ). More recently, we have tested late pruning as a practice to shift development and improve adaptation to warming in the Barossa Valley of Australia (Moran et al , Petrie et al ).…”

Calibrated, delayed-cane winter pruning controls yield and significantly postpones berry ripening parameters inVitis viniferaL. cv. Pinot Noir

“…Late spur pruning performed when buds are at the woolly stage has been traditionally used in cool climates to delay budburst and avoid spring frost consequences (Howell and Wolpert , Trought et al , Friend et al ). The delay achievable with such a technique is in the order of a few days and is typically maintained until around flowering.…”

Spatial analysis of frost risk to determine viticulture suitability in Tasmania, Australia

“…Indeed, a good compromise across all risk categories should imply a temperature threshold that represents frost risk more broadly across the survey responses, and hence, more likely to resemble frost damage as experienced by winegrowers. This is compounded further since different cultivars are susceptible to frost damage at various minimum temperature values depending on the time of the frost, environmental conditions and the phenological stage of the crop (Fuller and Telli 1999, Trought et al 1999, Fennell 2004, Friend et al 2011. This suggested that there were possible underestimations associated with mapped frost risk values at these locations.…”

“…Alternatively, response bias from survey respondents may have also systematically predisposed respondents to favour the most extreme option according to their own personal bias, or paradoxically, influence underestimation to the least severe option (Paulhus 1991). This is compounded further since different cultivars are susceptible to frost damage at various minimum temperature values depending on the time of the frost, environmental conditions and the phenological stage of the crop (Fuller and Telli 1999, Trought et al 1999, Fennell 2004, Friend et al 2011. In other words, respondents may portray the degree of frost damage catered specifically to their own cultivar and management regimes and not reflect frost events consistent with other vineyard sites.…”