Apple & pear production in a changing climate

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Apple and pear production is vulnerable to climate change and research is underway to help understand the affects and find ways to reduce any negative impacts.

This project aims to broadly answer the following questions:

  1. What are the potential impacts of a changing climate on apple and pear production systems in Australia?
  2. What are some of the options for adaptation to reduce risk and take advantage of potential opportunities?

Apple and pear production systems are sensitive to temperature throughout the growth cycle. These crops are dependent on a dormant period which requires accumulation of chill during the autumn and winter to promote bud burst and flowering. During the subsequent fruit growth phase, fruit size and quality are affected directly by climate, through temperature-driven impacts on growth processes, colour development and sunburn damage.

This project will collect flowering, yield and fruit quality data for a number of commercial apple and pear varieties from three pome fruit growing regions in Australia (Stanthorpe, Qld; Tatura, Vic; Manjimup, WA). Initially, the data will be used to help understand the relationships between:

  • temperature and flowering time and quality, and
  • temperature and fruit yield and quality.

From this information, the potential impacts of projected changes in climate will  be determined. The effectiveness of different types of netting, as well as  variety selection will be assessed as potential adaptation options.

See also:

Leaf fall 2014  Individual bud monitoring 2013

   Leaf fall, Applethorpe Research Station, Qld, 2014         Assessing flowering stages of individual buds in 2013

(Photos courtesy Dr Heidi Parkes, DAFF QLD)

Regional Chill Accumulation

Cumulative Chill Portions 2013 and 2014








Video: Dealing with seasonal climate risk and extreme weather events

Dealing with seasonal climate risk and extreme weather events, a presentation by Dr Ian Goodwin, Agriculture Victoria, at the Regional Innovation Forum - ‘Delivering innovation through the horticulture supply chain’, Horticulture Centre of Excellence, Tatura May 2016

A global evaluation of apple flowering phenology models for climate adaptation

Free online until May 27th 2017 -

This study presents the first evaluation of apple flowering phenology models using data from 14 sites across the globe. The dataset includes large variability in growing climates, a prerequisite to investigate phenology models for use in climate change applications. Two flowering stages, early and full, were investigated allowing for unique model evaluation based on both statistical performance and biological assumptions. Two overarching phenology models (Sequential and Chill Overlap) and two sub-models of chill (Dynamic and Triangular) and heat (GDH and Sigmoidal) were tested. Flowering times from the different sites illustrated the differing effects of contrasting winter and spring temperatures. Sites with similar springtime temperatures, but different winter temperatures, had different flowering patterns (warmer winter sites flowered later). Across all analyses, results from the Chill Overlap model were better than those from the Sequential model. Of the Chill Overlap models, those fitted with the Triangular or Dynamic chill model and the GDH heat sub-model performed well statistically and met the assumptions of the model across both flowering stages. The mild sites in the analysis were least well represented, regardless of model selection. This global evaluation demonstrated that flowering modelling in temperate fruit trees would progress through appropriate choices of overarching model, sub-models and parameters.


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Full bloom pome fruit thumbnail

Chill portion calculator for Australian fruit trees

In order to better estimate winter chill, a tool has been developed by Rebecca Darbyshire (University of Melbourne) to assist growers assess chill conditions in fruit tree orchards

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Heidipresentation May2014

Apples & pears in a changing climate powerpoint May2014

Presentation by Heidi Parkes, QLD DAFF, on Apples & Pears in a changing climate at the FGV review May 2014

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Fruit tree annual cycle thumbnail

Winter chill and fruit trees fact sheet

PICCC fact sheet

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