Research and development of temperate fruits in subtropical Australia

Abstract

The production of temperate fruits in subtropical regions of Australia has expanded rapidly in the past 10 years. Over 800 000 low-chill stone fruit, mainly peaches and nectarines, and to a lesser extent plums, have been planted in subtropical regions of Australia. Another temperate fruit gaining greater importance, because of its potential as an export fruit, is non-astringent persimmon. Over 200 000 trees of this fruit species have been planted to date. Management strategies for growing low-chill temperate fruits in subtropical climates are still being developed. Due to differences in phenology and physiology, management requirements used for high-chill cultivars grown in colder climates need to be modified for low-chill cultivars grown in subtropical climates. There has been a general improvement in tree productivity as growers experience with managing these fruits in non-traditional production areas increases. Recent surveys have established productivity benchmarks for low-chill stone ruit. Yields of very low-chill peach cultivars with short fruit development periods (80–90 days) such as Flordaprince can reach 27 t/ha. For cultivars with longer fruit development periods (100 – 120 days), such as Flordagold, yields may be as high as 51 t/ha. The trend is to plant trees at higher densities (1200–1800 trees/ha) and train these trees to a palmette system because of its ease of management. A small number of high-density orchards are using trees propagated from soft-wood cuttings rather than the more conventional, grafted trees. With higher density plantings the use of the growth retardant paclobutrazol and/or sequential summer prunings, to control tree vigour, is essential to prevent excessive shading and subsequent loss of productivity.