Articles
Investigating the effect of different autumn, winter, and spring temperature scenarios on budburst in apple trees
Article number
1366_51
Pages
413 – 420
Language
English
Abstract
Deciduous trees require sufficient winter chill to have a synchronised and condensed bloom period in spring.
When winter chilling is incomplete spring bud break is delayed and reduced and rest-breaking agents are commonly used in warm winter production areas to mitigate this problem.
However, historical commercial data indicates that bud break success can differ significantly across seasons despite comparable and sufficient chill accumulation.
In the same way, we often see differences in the efficacy of rest-breaking applications (timing and dosage) even with similar deficiencies in winter chill.
This indicates that the total amount of chill received during the dormant period is not the only determining factor for good bud break.
The aim of this study was to investigate the effects of different autumn, winter and spring temperature scenarios on the bud break pattern of apple trees.
For two consecutive years, nursery trees (M793 rootstock), grown in bags, were moved between two production sites with contrasting autumn and winter climates, warm and cold spring conditions were simulated in a glasshouse.
This resulted in eight different temperature scenarios across the three seasons.
Dormancy progression was quantified for each scenario by forcing trees at numerous occasions and expressing the time to bud break as a two linear joint line model.
Spring bud break was also monitored.
Cold winter temperatures contributed most to bud break success but autumn chill mitigated some of the lack of winter chill in years when winter chill is low.
Warm spring temperature are less important after sufficient winter chill has accumulated.
Therefore, successful bud break under mild winter conditions is not solely dependent on the amount of chill accumulated, but rather the distribution of the chill throughout the dormant period.
When winter chilling is incomplete spring bud break is delayed and reduced and rest-breaking agents are commonly used in warm winter production areas to mitigate this problem.
However, historical commercial data indicates that bud break success can differ significantly across seasons despite comparable and sufficient chill accumulation.
In the same way, we often see differences in the efficacy of rest-breaking applications (timing and dosage) even with similar deficiencies in winter chill.
This indicates that the total amount of chill received during the dormant period is not the only determining factor for good bud break.
The aim of this study was to investigate the effects of different autumn, winter and spring temperature scenarios on the bud break pattern of apple trees.
For two consecutive years, nursery trees (M793 rootstock), grown in bags, were moved between two production sites with contrasting autumn and winter climates, warm and cold spring conditions were simulated in a glasshouse.
This resulted in eight different temperature scenarios across the three seasons.
Dormancy progression was quantified for each scenario by forcing trees at numerous occasions and expressing the time to bud break as a two linear joint line model.
Spring bud break was also monitored.
Cold winter temperatures contributed most to bud break success but autumn chill mitigated some of the lack of winter chill in years when winter chill is low.
Warm spring temperature are less important after sufficient winter chill has accumulated.
Therefore, successful bud break under mild winter conditions is not solely dependent on the amount of chill accumulated, but rather the distribution of the chill throughout the dormant period.
Authors
E.D. Louw, L. Allderman, N.C. Cook
Keywords
apple (Malus × domestica Borkh.), inadequate winter chill, dormancy, bud break
Groups involved
- Division Plant-Environment Interactions in Field Systems
- Division Temperate Tree Fruits
- Division Temperate Tree Nuts
- Division Tropical and Subtropical Fruit and Nuts
- Division Horticulture for Development
- Division Vine and Berry Fruits
- Division Precision Horticulture and Engineering
- Commission Agroecology and Organic Farming Systems
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