THE TREE TOMATO OR 'TAMARILLO'
SCIENTIFIC NAME: Cyphomandra betacea
FAMILY: Solanaceae
The tamarillo or tree tomato (Cyphomandra betacea) is a native of the Andean region of Peru, and has been cultivated in other parts of the world, such as Sri Lanka, India, the South East Asian Archipelago, and also in New Zealand on a commercial scale.
The genus Cyphomandra belongs to the family Solanaceae, which contains about 30 species of soft-wood shrubs that are all natives of Central and South America and the West Indies. The tamarillo is a small tree which grows to about 3 metres. The fruit can be eaten raw, or cooked in sauce, jams, chutneys and savoury dishes. In fact, it can be used wherever ordinary tomatoes are used. There are two main types, the yellow and the red. The red being more widely-grown because of its bright colour, but the yellow is more popular with home gardeners as it is sweeter.
Being a sub-tropical shrub, young trees are intolerant of frost; more mature trees will take a little frost as long as it is slight and infrequent. Trees prefer light, well-drained soils and need ample moisture throughout summer, however they will not stand waterlogging. The large leaves and extremely brittle branches make it very prone to wind damage, so they need to be protected with permanent windbreaks. The branches will break off easily when they are heavily laden with fruit, even in quite light winds.
Tamarillos are easily propagated from seed or cuttings. Cuttings produce lower bushy plants compared with seedlings, which generally produce a straight main stem up to 1.5 m before they branch. If a more bushy plant is preferred from a seedling, pinch out the top at approximately 1 metre. Seedlings should be planted out in October and should be kept moist so that early rapid growth can be obtained. Cuttings can be taken in Autumn or Spring, selecting 1- to 2-year-old-wood, approximately 45 cm (18") long. Remove all the leaves, and cut the shoot square at the base just below a node. When setting out in the orchard, thoroughly mix 400 to 500 g of blood and bone in the bottom of the planting hole.
Trees are self pollinating and produce their fruit on current season's growth. When pruning your trees, remove dead, diseased and crowded old wood. To promote strong new growth, cut back the laterals that have fruited. If trees are not pruned, the new fruiting wood gradually extends from the ends of the branches and laterals and the middle of the tree are left more or less barren. The fruit that is produced on the ends of these branches and laterals which are weak and spindly are generally poor in size, and the weight of the fruit will cause them to break.
If you prune judiciously, you will maintain a strong framework and this will encourage good quality fruit to grow in towards the centre of the tree, on branches that are strong enough to bear their weight. Trees can be pruned any time from Spring to November, depending on when you want your next year's crop to mature. Pruning in early Spring results in early maturity. Pruning in October or November will result in a later crop.
A complete NPK fertilizer that is rich in nitrogen, similar to the type used on citrus trees is recommended. This should be applied in three separate dressings, one-third just before pruning, to stimulate Spring growth, another third about a month later before the onset of the dry weather, and the last third in February, after rain to help swell the developing fruit.
Tamarillos usually start to bear within 18 months of planting. They usually come into full production within 3 or 4 years, but from a commercial point of view they are usually only profitable for 7 - 8 years. Under suitable conditions, a tree may produce 20 kg or more fruit annually. Several pickings are necessary, as fruit does not ripen on the tree all at once. However it is of an advantage to the home gardener, as you will have a continuous supply of fruit from March approximately through winter when not much other fruit is available.
DATE: November 1990
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