The origin is believed to be in Peru, Ecuador and southern Columbia. It is now grown in most of Central America, Puerto Rico, Florida’s warm coasts and Australia.
This perennial plant with orange fruit is used most commonly for juice and for flavoring other juices. It is also used in ice cream, sherbets, jellies and jams. In the species which are spiny, hairs can be brushed off and the fruit consumed by cutting the fruit in half and squeezing the contents into the mouth. People with sensitive skin may find the hairs on the fruit irritating and should protect their hands.
It is a spreading shrub, 2.4 m (8 ft) high with rich purple colored leaves. The Naranjilla has great potential as a crop for small farms if its susceptibility to root knot nematodes can be eliminated. Grafting on nematode resistant rootstock is essential in southern Florida. The crop prefers short days within a long growing season, cool, moist growing conditions and well-drained, fertile soil. It can also grow on poor, scarified limestone. Crops have been produced at sea level and up to 2,400 m (8,000 ft) elevation but it will not tolerate frost or high temperatures above 30° C (85° F). Naranjilla will grow rapidly from seed and bear fruit in one year, grafted plants in six months. Old woody stems should be pruned after harvest. In most areas, the plant produces for 3-4 years before productivity declines. Plants do best in semi-shade and protected from wind. It can also be planted as an attractive ornamental.
Harvesting and Seed Production
The fruits are ripe when the exterior has turned from brown to orange with skin resembling an orange. For transportation or storage of up to 10 days with no refrigeration, the fruits are picked earlier, just as the skin shows a slight orange color. The brown hairs are brushed off easily. The interior flesh and seeds resemble those of a tomato. To save the seeds, they should be spread out in the shade to ferment the flesh, and then washed, air dried and dusted with a fungicide. It can also be propagated by air-layering or cuttings.
Pests and Diseases
Since it is susceptible to nematodes, it is necessary to rotate the crop frequently. At present there is research going on to produce nematode resistant Naranjilla by hybridizing with nematode-resistant wild relatives. Bacterial wilt can also be a problem.
Cooking and Nutrition
Naranjilla fruit juice is slightly acid, greenish-yellow in color, high (31-83 mg.) in ascorbic acid and very versatile in dessert recipes. Naranjilla sherbet is made by mixing juice, syrup, sugar, water, lime juice and partially freezing, then beating into a froth and freezing.