Assessment of phenology, growth characteristics and berry composition in a hot Australian climate to identify wine cultivars adapted to climate change. (27th February 2022) - Clingeleffer, P.R.
Abstract: Background and Aims: The phenology, growth traits and fruit composition of cultivars in the CSIRO germplasm collection, located in a hot Australian region, were assessed to identify those adapted to climate change. Methods and Results: The study involved 465 cultivars assessed over four seasons. Differences in key traits included a 5‐week range in budburst; a 4‐month harvest window; a twofold difference in the growth period from budburst to harvest; a fivefold difference in fruitfulness and in leaf area index; a 15‐fold difference in berry mass; and a five‐ to 15‐fold difference in berry mineral ion concentration and large differences in fruit composition. The latter included pH (range 3.48–4.95), titratable acidity (1.60–9.07 g/L), tartaric acid (2.20–7.95 g/L), malic acid (0.80–7.74 g/L), yeast assimilable nitrogen (70–505 mg/L) and, in red wine cultivars, total anthocyanins (0.04–5.79 mg/g) and phenolic compounds (0.55–3.60 a.u.). Conclusions: Cultivars grown under hot conditions with late budburst to minimise frost risks; short growth periods and small canopies to improve water use efficiency; and early and late ripening to extend the season have been identified. Early ripening cultivars had better fruit composition than late ripening cultivars. Significance: Opportunities to broaden genetic diversity will enhance the capability of the wine industry to meet challenges associated with climate change. Poor fruit composition, however, associated with high pH is a limiting factor under hot conditions.