KEY INCREASES IN RISKS
- Loss of chilling, with greater impacts in warm and mid-cool areas (lower impacts in the coldest areas).
- Late-autumn heat.
- Desiccating weather (heat, wind, low RH) during flowering with implications for early, mid and late flowering cultivars, especially in the Breede, Riviersonderend and Klein Karoo, and also in Ceres and Tulbagh.
- More erratic weather and higher frequencies of extreme events such as heat waves, cold snaps in-between warm periods, hail/sleet, etc.
- Altered phenologies and harvest dates resulting from shifting flowering periods for different cultivars (with repercussions for cross-pollination), less synchronization of flowering, increased within-tree variability and mixed maturities, and contracted or extended flowering, all negatively affecting logistics.
- Impacts on yield and fruit quality, including where the fruit developmental period is shortened so that target fruit sizes are not attained and fruit storability is decreased
- Increased fruit sunburn.
- Greater pest pressure in the early season with pests starting earlier and having more generations in this period.
KEY POSITIVE CHANGES
- Increasing Growing Degree Hours during flowering and fruit set
- Reduction in cold hours during pollination and fertilization
- Reduction in frost risk (although even a small remaining risk can be devastating)
- Variability of daily maximum and minimum temperatures not likely to change.
ADAPTATION RESPONSES
- Systematic observations and ongoing analysis of changing climatic conditions in various production areas, and where possible in specific microclimates in an area
- Long-term cultivar and sport evaluations across different climatic regions, with development of a database for ongoing statistics and analysis
- Availability of cultivars and rootstocks (for each of the generic fruit types) with a range of chill requirements
- Use of redder cultivars and sports
- Specific information and guidance to growers on cultivar and rootstock selections for specific production areas and microclimates
- Best practice use of effective rest breaking agents and thinning agents where they are (and become) essential for good production and fruit quality
- Guidance to growers on area-wide shifts from one fruit type to another with lower chill requirements and heat sensitivity
- Assessment of, and responses to, disruptions in harvest schedules and mixed maturities (within-tree variability)
- Use of multiple cross pollinator species.