CSIRO Unique Tastes
5 Jan 2011
Australian Blood LimeA The Australian Blood Lime is a hybrid between Citrus australasica var. sanguinea (the red finger lime) and the Rangpur lime (Citrus x limonia). The original parent tree has selected in 1990 at CSIRO, Merbein. Under the right conditions the tree produces striking, bloodred coloured fruit, which greatly enhances the appeal of the fresh and processed product. The variety also has potential as an ornamental tree. Fruit is produced on an attractive, dense, upright shrub to small tree, usually 2 to 3 m high and 2 m wide with dark, glossy-green foliage and red growth flushes. The ovalshaped leaves are approximately 25 to 35 mm long by 15 mm wide, with slightly serrated edges. Short, stiff, slender. Blood lime fruit Australian native citrus 5 spines are present in the leaf axils. These spines pose a hindrance to hand picking and are a significant contributing factor to post harvest problems with this cultivar. The spines can damage the fruit.
Fruits ripen in winter, are oval in shape and are usually 30 to 50 mm long, by 20 to 30 mm wide. The skin colour may range from gold, with red flecking, to a uniform intense blood red, while flesh and juice may show red tinges or may occasionally be more intensely red. Seasonal, geographic and harvest timing practices appear to influence the intensity of colour development. Seeds are small and plump. Juice squeezed from the fruit has a sharp, crisp/clean flavour with pH (approx 3.4) and Brix:Acid Ratio (approx 1.0 to 1.5) similar to the West Indian Lime. The crop is carried on the previous season’s growth, often on long weeping shoots, which may be covered later by a dense canopy growth. Pruning and nutrition management may be necessary to reduce this growth and present the fruit in such a way to minimize fruit damage and make harvesting easier. At Merbein, the fruit of the experimental planting ripens in June to August with the fruit remaining on the tree with colour until October. In commercial cultivation a high incidence of fruit drop has often stimulating harvest in June, with little fruit held on the tree. While it is early days for this cultivar, post harvest problems have been an issue. In the 2001 harvest, fruit quality problems were encountered due to Sour Rot, with thorn damage, tree habit, management and seasonal issues involved. Physiological breakdown of packed fruit also contributed to losses.