Tamarillo, is a small tree or shrub in the flowering plant family Solanaceae (the nightshade family). It is best known as the species that bears the tamarillo, an egg-shaped edible fruit. It is also known as the tree tomato,[tamamoro, and tomate de árbol in South America.
The tamarillo is native to the Andes of Ecuador, Colombia, Peru, Chile, and Bolivia. Today, it is still cultivated in gardens and small orchards for local production, and it is one of the most popular fruits in these regions. Other regions of cultivation are the subtropical areas throughout the world, such as Rwanda, South Africa, India, Hong Kong, China, United States, Australia, and New Zealand.
The first internationally marketed crop of tamarillos in Australia was produced around 1996, although permaculture and exotic fruit enthusiasts had increasingly grown the fruit around the country from the mid-1970s on.
In New Zealand, about 2,000 tons are produced on 200 hectares of land and exported to the United States, Japan and Europe. For the export, the existing marketing channels developed for the kiwifruit are used.
The tamarillo is also successfully grown at higher elevations of Malaysia and the Philippines, and in Puerto Rico. In the hot tropical lowlands, it develops only small fruits and fruit setting is seldom.
Prior to 1967, the tamarillo was known as the "tree tomato" in New Zealand, but a new name was chosen by the New Zealand Tree Tomato Promotions Council in order to distinguish it from the ordinary garden tomato and increase its exotic appeal. The choice is variously explained by similarity to the word "tomato", the Spanish word "amarillo", meaning yellow, and a variation on the Maori word "tama", for "leadership".
The plant is a fast-growing tree that grows up to 5 meters. Peak production is reached after 4 years, and the life expectancy is about 12 years. The tree usually forms a single upright trunk with lateral branches. The flowers and fruits hang from the lateral branches. The leaves are large, simple and perennial, and have a strong pungent smell. The flowers are pink-white, and form clusters of 10 to 50 flowers. They produce 1 to 6 fruits per cluster. Plants can set fruit without cross-pollination, but the flowers are fragrant and attract insects. Cross-pollination seems to improve fruit set. The roots are shallow and not very pronounced, therefore the plant is not tolerant to drought stress, and can be damaged by strong winds. Tamarillos will hybridize with many other solanaceae, though the hybrid fruits will be sterile, and unpalatable in some instances.
The fruits are egg shaped and about 4-10 centimeters long. Their color varies from yellow and orange to red and almost purple. Sometimes they have dark, longitudinal stripes. Red fruits are more acetous, yellow and orange fruits are sweeter. The flesh has a firm texture and contains more and larger seeds than a common tomato. The fruits are very high in vitamins and iron and low in calories (only about 40 calories per fruit
Pruning can help to control fruit size, plant size, harvest date and to simplify the harvest of fruits. Cutting the tip of young plants leads to the desired branch height. Once the tree shape has been formed, pruning is reduced to the removal of old or dead wood and previously fruited branches, since branches that have already carried fruits will produce smaller fruits with lower quality the next time. Light pruning leads to medium sized, heavy pruning to large sized fruits. Basal shoots should be removed. When plants are grown in greenhouses, pruning prevents excessive vegetative growth.
When the tree is about 1 to 1.5 metres in height, it is advisable to cut the roots on one side and lean the tree to the other (in the direction of the midday sun at about 30 to 45 degrees). This allows fruiting branches to grow all along the trunk rather than just at the top.
Tamarillo seedlings, 6 months old
Since the plants are sensitive to drought stress, mulching can help to preserve moisture in the soil. It can also be a strategy to suppress weeds, as other soil management techniques such as plowing is not possible due to the shallow and sensitive root system.
More info at https://en.wikipedia.org/wiki/Tamarillo
Juan Gonzalo Angel