The papaya (from Carib via Spanish), is the fruit of the plant Carica papaya, in the genus Carica. It is native to the tropics of the Americas, and was cultivated in Mexico several centuries before the emergence of the Mesoamerican classic cultures. It is sometimes called a "big melon" or a "paw paw" but the North American pawpaw is a different species, in the genus Asimina.
It is a large tree-like plant, the single stem growing from 5 to 10 meters tall, with spirally arranged leaves confined to the top of the trunk; the lower trunk is conspicuously scarred where leaves and fruit were borne. The leaves are large, 50-70 cm diameter, deeply palmately lobed with 7 lobes. The tree is usually unbranched if unlopped. The flowers are similar in shape to the flowers of the Plumeria but are much smaller and wax like. They appear on the axils of the leaves, maturing into the large 15-45 cm long, 10-30 cm diameter fruit. The fruit is ripe when it feels soft (like a ripe avocado or a bit softer) and its skin has attained an amber to orange hue. The fruit's taste is vaguely similar to pineapple and peach, although much milder without the tartness.
It is the first fruit tree to have its genome deciphered.[1]
Cultivation and uses of papaya
Originally from southern Mexico, Central America and northern South America, the papaya is now cultivated in most countries with a tropical climate, such as Brazil, India, South Africa, Sri Lanka, and Southeast Asia.
The ripe fruit is usually eaten raw, without the skin or seeds. The unripe green fruit of papaya can be eaten cooked, usually in curries, salads and stews. It also has a relatively high amount of pectin, which can be used to make jellies.
Green papaya fruit and the tree's latex are both rich in an enzyme called papain, a protease which is useful in tenderizing meat and other proteins. Its ability to break down tough meat fibers was utilized for thousands of years by indigenous Americans. It is included as a component in powdered meat tenderizers, and is also marketed in tablet form to remedy digestive problems. Green papaya is used in Thai cuisine, both raw and cooked.[2]
| Papaya, raw Nutritional value per 100 g (3.5 oz) | ||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Energy 40 kcal 160 kJ | ||||||||||||||||||||||||||||||||||||
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| Percentages are relative to US recommendations for adults. | ||||||||||||||||||||||||||||||||||||
Papain is also popular (in countries where it grows) as a topical application in the treatment of cuts, rashes, stings and burns. Papain ointment is commonly made from fermented papaya flesh, and is applied as a gel-like paste. Harrison Ford was treated for a ruptured disc incurred during filming of Indiana Jones and the Temple of Doom by having papain injected into his back.[3]
Women in India, Pakistan, Sri Lanka, and other parts of the world have long used green papaya as a folk remedy for contraception and abortion.[citation needed] Medical research in animals has confirmed the contraceptive and abortifacient capability of papaya, and also found that papaya seeds have contraceptive effects in adult male langur monkeys, possibly in adult male humans as well.[4] Unripe papaya is especially effective in large amounts or high doses. Papaya is not teratogenic and will not cause miscarriage in small, ripe amounts. Phytochemicals in papaya may suppress the effects of progesterone.[5]
The black seeds are edible and have a sharp, spicy taste. They are sometimes ground up and used as a substitute for black pepper. In some parts of Asia the young leaves of papaya are steamed and eaten like spinach. In parts of the world papaya leaves are made into tea as a preventative for Malaria, though there is no real scientific evidence for the effectiveness of this treatment. [6]
The papaya fruit is susceptible to the Papaya Fruit Fly. This wasp-like fly lays its eggs in young fruit. In cultivation it grows rapidly fruiting within 3 years, however it is highly frost sensitive.
In the 1990s, two varieties of papaya, SunUp and Rainbow, that had been genetically-modified to be resistant to the papaya ring spot virus, were introduced into Hawaii. [1] By 2004, non-genetically modified and organic papayas throughout Hawaii had experienced widespread contamination from the genetically-modified varieties.[2]
Allergies and side-effects
Papaya is frequently used for hair conditioner but should be used in small proportions. Caution should be taken when harvesting, as papaya is known to release a latex fluid when not quite ripe, which can cause irritation and provoke allergic reaction in some people. The papaya fruit, seeds, latex, and leaves also contains carpaine, an anthelmintic alkaloid which could be dangerous in high doses.
It is also commonly believed to induce abortions and is best avoided by pregnant women.
Excessive consumption of papaya, as of carrots, can cause carotenemia, the yellowing of soles and palms which is otherwise harmless
LAND PREPARATION AND PLANTING
Land preparation for papaya orchard is similar to other upland crops. First clear the fields; then plow and harrow alternately about 2 to 3 times to kill weeds and provide good internal drainage. The distance of planting papaya ranges from 2 to 3 meters depending on the variety.
Papaya plants are usually planted by direct seedling in the field. Place 5 or more seeds in each hole; then cover with ¼ inch of soil. When fresh seeds are used, seeds will germinate in 10 to 14 days after planting. Seed germination is better and faster if the gelatinous envelope (sarcotestae) surrounding the seed is removed by means of the fingers. In some cases, seedlings are started in the nursery by sowing seeds in seed plots or individual containers such as in cans or plastic bags. Sow 3 to 4 seeds per container. Use sterilized soil to avoid nematode infestation and damping-off. Seedlings in the nursery should be grown under full sunlight to produce vigorous and hardy seedlings. Care should be taken not to disturb the root system. Constant watering is essential until plants are well-established. Seedlings are transplanted when there are 3 to 4 leaves.
THINNING
Thin papaya seedlings in the field 4 to 6 weeks after emergence. Leave only 3 of the strongest seedlings in each hole. Save plants that are spaced far enough from one another to allow minimum competition for sunlight and nutrients.
The second and final thinning in the field should be done as soon as flowers appear. This is usually 4 to 6 months after seed germination. At this stage, leave one tree seedling per planting hole. In plantation where female trees are grown, some pollinating trees of either male or hermaphrodite forms should be preserved during the thinning process. Allow one male plant to grow for every 15 to 20 female trees for pollination purposes.
CARE OF PAPAYA PLANTATION
Establishment of Windbreaks
Windbreaks are necessary in areas where strong winds prevail. Local materials used as windbreaks are ipil-ipil and madre de cacao. The distance between windbreaks varies with location. Where winds blow horizontally across the plantation, a common rule of thumb is to space windbreaks at a distance of 20-30 times the height of windbreak trees. Where winds come in different directions and angles, it is necessary to have windbreaks half as close.
In general, a good windbreak should be permeable, allowing some air to pass through.
Fertilization
Factors such as soil types, rainfall, locations, cultural practices, and age of plant influence fertilization practices. Start fertilizing when seeds are planted or when seedlings are transplanted in the field. Mix a handful (5-10gms.) of complete fertilizer (14-14-14) with the soil at the bottom of the hole before planting. As papaya seedlings grow larger, more fertilizer is applied.
Weed Control
Weeds can be controlled by mechanical and chemical means. Hand-weed when papaya plants are less than 2- ½ meter high. Always keep one meter area around the trunk free from weeds.
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