Star Ruby Citrus paradisi Macf. Grapefruit
Ahmer, Cant, Rev Cant, Rosso, Rubra, Star Ruby 4n, Sunrise, Texas, Texas Star
'Star Ruby' is a quite late variety created in 1959 by R. A. Hensz in the research centre in Weslaco, Texas from a 'Hudson' variety seed exposed to radiation. It was first released to public in 1971.
The tree seems to be very compact, mainly because of the amount of branches and small habitus, which resembles a shrub. 'Star Ruby' is a heat loving variety, but its sensitive to temperatures above 45°C, herbicides, gummosis, phytoftora, antracnosa, chlorosis and tristeza, which might be a result of radiation mutation. It has lots of average-sized leaves with wings on their petioles and typical light spots (they are sometimes mistaken for diseases). If the tree is not trimmed and cut regularly, yields are significantly lower. It is probably the most demanding and difficult to grow variety of all. Plentiful flowers are white and they grow in clusters. The fruit is spherical, average or even big (7,5-10,5cm), weighs 350-450g and is slightly smaller than other pigmented varieties. It has smooth, thin (7-12mm), easy to peel, yellow rind with red spots and is better colored in shade than 'Rio Red'. Intensive red pulp color is the result of high lykopen amounts; it is the most intensively colored variety of all. The pulp is rich in soluble slats, sugars and has less acids than 'Redblush'. It contains roughly 50% of juices in all 14 segments. Ripe fruit can hang very long on the tree and it can be harvested from October to March.
'Star Ruby' has better pigmentation in cooler climates, in commercial tropical cultivation ethylene is used to remove the remains of green color and better pigmentation of the pulp. If the 'Star Ruby' variety is grafted on oranges, the ripe fruit is usually sweeter, but the trees grow badly in clogged soils. When compared to other varieties, it has shorter economical vitality (by 3-4 years), so it's substituted in major cultivation areas - Texas and Florida - with 'Rio Red'. The most popular Australian clone 'Cant' is a result of selection made many years ago, it is almost identical to 'Star Ruby' in all the important characteristics.