A pitaya is the fruit of several different cactus species indigenous to the Americas. Pitaya usually refers to fruit of the genus Stenocereus, while pitahaya or dragon fruit refers to fruit of the genus Selenicereus (formerly Hylocereus), both in the family Cactaceae. Dragon fruit is cultivated in Mexico, South Asia, Southeast Asia, East Asia, the United States, the Caribbean, Australia, Mesoamerica and throughout tropical and subtropical regions of the world.
Pritish Kumar in this post discusses Tropical Fruit Known as Pitaya Fruit, its geographical location, varieties, cultivation techniques and diseases that impact it.
Pitaya fruit cross section
Geography
Pitahaya or dragon fruit is native to southern Mexico and Central America. The dragon fruit is cultivated in East Asia, South Asia, Southeast Asia, the United States, the Caribbean, Australia, and throughout tropical and subtropical regions of the world.
Varieties
Stenocereus
Stenocereus fruit (sour pitayas) are a variety that is commonly eaten in the arid regions of the Americas. They are sourer and refreshing, with juicier flesh and a stronger taste. The sour pitaya or pitaya agria in the Sonoran Desert has been an important food source for indigenous peoples of the Americas.
Dragon fruit Selenicereus
Sweet pitayas come in three types, all with leathery, slightly leafy skin:
1)Selenicereus undatus (Pitaya blanca or white-fleshed pitaya, also known as Hylocereus undatus) has pink-skinned fruit with white flesh. This is the most commonly seen “dragon fruit”.
2)Selenicereus costaricensis (Pitaya roja or red-fleshed pitaya, also known as Hylocereus costaricensis, and possibly incorrectly as Hylocereus polyrhizus) has red-skinned fruit with red flesh.
3)Selenicereus megalanthus (Pitaya amarilla or yellow pitaya, also known as Hylocereus megalanthus) has yellow-skinned fruit with white flesh.
Cultivation
After a thorough cleaning of the seeds from the pulp of the fruit, the seeds may be stored when dried. The ideal fruit is unblemished and overripe.
Seeds grow well in a compost or potting soil mix – even as a potted indoor plant. Pitaya cacti usually germinate after between 11 and 14 days after shallow planting. As they are cacti, overwatering is a concern for home growers. As their growth continues, these climbing plants will find something to climb on, which can involve putting aerial roots down from the branches in addition to the basal roots. Once the plant reaches a mature 4.5 kilograms (10 pounds) in weight, the plant may flower.
Commercial plantings can be done at high density with between 1,100 and 1,350 per hectare (445 and 546/acre). Plants can take up to 60 months/260 weeks to come into full commercial production, at which stage yields of 20 to 30 metric tons (22 to 33 short tons) can be expected.
About the plant
Pitaya flowers bloom overnight and usually wilt by the evening. They rely on nocturnal pollinators such as bats or moths for fertilization. Self-fertilization will not produce fruit in some species, and while cross-breeding has resulted in several “self-fertile” varieties, cross-pollinating with a second, genetically distinct plant of the same species generally increases fruit set and quality. This limits the capability of home growers to produce the fruit. However, the plants can flower between three and six times in a year depending on growing conditions. Like other cacti, if a healthy piece of the stem is broken off, it may take root in soil and become its own plant.
The plants can endure temperatures up to 40 °C (104 °F) and very short periods of frost, but will not survive long exposure to freezing temperatures. The cacti thrive most in USDA zones 10–11, but may survive outdoors in zone 9a or 9b.
Selenicereus has adapted to live in dry tropical climates with a moderate amount of rain. In numerous regions, it has escaped cultivation to become a weed and is classified as an invasive weed in some countries.
Pests and diseases
Stems and fruits are susceptible to several diseases caused by fungi, bacteria, a nematode, and a virus. Overwatering or excessive rainfall can cause the flowers to drop and fruit to rot. The bacterium Xanthomonas campestris causes the stems to rot. Dothiorella fungi can cause brown spots on the fruit. Other fungi known to infect pitaya include Botryosphaeria dothidea, Colletotrichum gloeosporioides and Bipolaris cactivora.
Nutrients
As the nutrient content of raw pitaya has not been thoroughly analyzed or published as of 2019, the USDA Food Data Central database reports one limited product label entry from a manufacturer of a branded product, showing that a 100-gram (3+1⁄2-ounce) reference serving of dried pitaya provides 1,100 kilojoules (264 kilocalories) of food energy, 82% carbohydrates, 4% protein, and 11% of the Daily Value each for vitamin C and calcium.
