Origin and distribution
Tree tomato also known as tamarillo is a native to the Andes of Peru, Chile, Ecuador, Columbia and Bolivia and it belongs to the family Solanaceae. It is cultivated in sub-tropical areas throughout the world, such as South Africa, India, Hong Kong, China, USA, Australia and New Zealand. It is cultivated in Venezuela and grown in the highlands of Costa Rica, Guatemala, Jamaica, Puerto Rico and Haiti.
Tree tomato is also known as tamarillo, tomate and Java plum. It was introduced by a nurseryman of New Zealand in 1891, and commercial growing on a small scale began about 1920. In 1970, the New Zealanders named it tamarillo, which has become the standard commercial designation for tree tomato. The USDA received seeds from Argentina in 1913 from Sumatra and Ceylon in 1926. In India, it is grown sporadically in the mid hills of Uttarakhand, Himachal Pradesh, Nilgiris and hills of Assam at an elevation of 1000-2000 m.
The plants of tree tomato are perennial, self-pollinated, fast growing, half-woody that grows up to 5 m, usually forms a single upright trunk with several lateral branches. The leaves are odorous, evergreen, alternate, more or less heart-shaped at the base, ovate, pointed at apex, 10-35 cm long, 4-12 cm broad, softly hairy, with conspicuous coarse veins. The flowers are pinkish white and form clusters of 10-25 flowers. The long stalked pendent fruit borne or in clusters of 3-12, egg shaped but pointed at both ends and capped with persistent conical calyx.
Fruits size ranges 5-10 cm long and 4-5 cm wide. Skin colour deep-purple, blood red, orange or yellow or may have longitudinal stripes. Flesh colour orange-red, yellow or creamish-yellow. Pulp taste sub-acidic to sweet. Nutritional value: Unripe fruits are used in pickle preparation and eaten by scooping the flesh because fruit skin is bitter in taste. Several products viz. chutneys, curries, juices are prepared from the fruit. The fruits of tree tomato are very high in vitamins and iron and low in calories.
The tree tomato prefers sub-tropical climate, with rainfall 600-4000 mm and annual temperatures ranges 15-200C. The plants are susceptible to frost (-2.00C and drought stress), they grow well in light, deep, fertile soils and permeable with a pH 5.0-8.5. Plants can be propagated by both using seeds or cuttings but propagation by seeds is easy and ideal. The seeds are small (1.2-2.0 g/1000 seeds).
Generally 200-250 g healthy seeds are sufficient to raise the nursery for one-hectare land. Seeds are sown in nursery beds in the month of April-May and 5-6 week old seedlings are planted in well-prepared soil at the row to row distance 3 m and plant to plant 1.5 m. Rainy season is considered good for plantation. Plants grow from cuttings branched out earlier and result in more shrub like plants that are suitable for exposed sites.
Cuttings should be taken from based and aerial parts. Plants grown from cuttings should be kept in the nursery until they reach a height 15-20 cm. The tree grows very quickly and able to bear fruits after 2 years. Fruits are of medium size 80-100 g green before maturity and fully ripped fruit is red with purplish stripes. The fruits do not mature simultaneously.Occasionally pruning is require in removing old or dead woods and previously fruited branches, because old branches produce smaller fruits. Weeding should be done in the plant basin and mulching is common practice to preserve moisture in the soil.
Plants need a continuous supply of water due to their shallow root system. To get healthy and quality fruits, the fertilizer 170 kg N, 45 kg P and 130 kg K per hectare is recommended. Phosphorus and potassium should be applied in the beginning of the season and nitrogen applications throughout the year in several equal doses.The insect pests and diseases are not very much problem. However, insect like mites and aphids can be easily controlled by a spray of malathion (0.05%) or endosulfan (0.05%) as soon as the attack is noticed.
Two accessions of tree tomato viz. EC25897 and EC39826 were introduced by NBPGR from Argentina in 1962 and 1967 and one accession IC349909 was collected from locally been established in the field gene bank. Several propagated plants of tree tomato have been distributed to the researchers and farmers. Important cultivars of tree tomato available in other countries are Red Beau, Goldmine, Bold Gold, Inca Gold, Oratia Red, Rothman, Ruby Red and Solid Gold.
- National Bureau of Plant Genetic Resources Regional Station Phagli, Shimla