Papaya is a tropical and subtropical evergreen softwood small tree, 8-10 meters high, with milk. Its stem is unbranched or sometimes branched at the damage, with stipules arranged in a spiral. The fruit of papaya grows on the tree and looks like a melon, hence the name papaya. Papaya milk is the main ingredient for making loose meat powder. The flowering and fruiting period of papaya is year-round.
Papaya morphological characteristics
The leaves of papaya are large, clustered at the top of the stem, nearly shield-shaped, up to 60 cm in diameter, usually 5-9 deeply divided, and each lobe is pinnately divided; the petiole is hollow, up to 60-100 cm.
The flowers are unisexual or bisexual. Some varieties occasionally produce bisexual flowers or female flowers on male plants and bear fruit, and sometimes a few male flowers appear on female plants. There are male plants, female plants and bisexual plants. Male flowers: arranged in panicles, up to 1 m long, drooping. The flowers of papaya are sessile; the sepals are joined at the base; the corolla is creamy yellow, and the corolla tube is thin and tubular, 1.6-2.5 cm long, and the corolla lobes 5, lanceolate, about 1.8 cm long and 4.5 mm wide. The stamens of papaya are 10, 5 long and 5 short, a few short filaments, and the long filaments are white with white hairs; the ovary has degenerated. Female flowers: solitary or arranged into corymbs inflorescences, with the short stalk or nearly sessile, with 5 sepals, about 1 cm long, connate below the middle; corolla lobes 5, separate, creamy yellow or yellowish-white, Oblong or lanceolate, 5-6.2 cm long and 1.2-2 cm wide. Ovary of papaya superior, ovoid, sessile, style 5, stigma several lobed, sub-tassel shaped.
Papaya is a bisexual flower. It has 5 stamens, which are inserted on the very short corolla tube near the base of the ovary, or 10 are inserted on the longer corolla tube, arranged in 2 rounds, the length of the tube is 1.9-2.5 cm, and the corolla lobes Oblong, about 2.8 cm long and 9 mm wide, the ovary is smaller than the female ovary.
Papaya has berry flesh, orange or yellow when mature, oblong, obovate, pear-shaped or nearly spherical, 10-30 cm or longer, soft and juicy, and sweet. Papaya has a large number of seeds, ovoid, black when mature, with fleshy outer testa and woody inner testa with wrinkles.
Papaya growth habit and growing environment and distribution
Papaya likes the tropical climate with high temperatures and humidity. It is not cold-tolerant and will wither when it encounters frost. Because of its shallow root system, avoid gale and stagnant water. The requirements for geothermal are not strict, and it can be cultivated in hills and mountains. Papaya has strong adaptability to the soil, but it is better to grow in loose and fertile sandy loam or loam.
Papaya is most suitable for planting in warm areas with an average annual temperature of 22～25℃ and an annual rainfall of 1500～2000 mm. The suitable growth temperature is 25～32℃. The temperature around 10℃ tends to grow slowly, and young organs begin to appear at 5℃. Freezing damage, withered leaves at 0℃. Too high temperature is also detrimental to the growth and development of papaya. Papaya has strong soil adaptability, but it is suitable to be acidic to neutral.
Papaya is distributed in tropical and subtropical regions of the world. It is native to southern Mexico and neighboring Central America and is now mainly distributed in Southeast Asia, Malaysia, the Philippines, Thailand, Vietnam, Myanmar, Indonesia, India, Sri Lanka, Central and South America, West Indies, Florida, Hawaii, and Cuba. And Australia. Papaya in China is mainly distributed in Guangdong, Hainan, Guangxi, Yunnan, Fujian, Taiwan and other provinces.
Papaya efficacy and role
The papaya has smooth and beautiful skin, thick and delicate flesh, rich aroma, rich juice, sweet and delicious, and rich nutrition. Papaya is rich in more than 17 kinds of amino acids, calcium, iron and so on. It also contains papain and papaya base. Half a medium-sized papaya is enough to provide vitamin C for adults all day long.
The fruit of papaya can not only be used as fruits and vegetables but also has a variety of medicinal values. The milk of immature papaya can be extracted from papaya, which is an excellent raw material for making cosmetics and has the effect of beauty and whitening.
According to reports, when Americans cook beef, they like to blend or inject papaya into the beef. In this way, the beef will be cooked quickly, and it will taste tender and easy to digest. The natives of tropical America have been using the green leaves of the claws to wrap meat overnight before cooking, or co-cooking the leaves with the meat to soften the texture of the meat. In Xishuangbanna, semi-ripe papaya is often eaten as a vegetable. There are two common ways to eat it, one is to use it to cook soup, it is fragrant and slightly sweet, and it is very delicious; the other is to cut it into thin strips and add vinegar, soy sauce, chili powder, monosodium glutamate and other condiments The cold mix is eaten raw, crisp, sour and spicy, slightly sweetened. Ripe papaya is a high-end rare fruit with rich nutrition and contains a lot of protein, vitamin C, carotene and protease. It can be eaten fresh or made into drinks, syrup, pectin, ice cream, preserved fruits, dried fruits, etc. Protease has the effects of invigorating the stomach, dispelling worms and reducing swelling, and cures dyspepsia, high blood pressure, small milk, arthralgia, ascariasis, furunculosis, swelling, and centipede bites. Therefore, ripe papaya is an ideal fruit after a meal. As early as the 15th century, Columbus discovered that the natives of the Caribbean often ate some papaya desserts after eating a lot of fish and meat to prevent indigestion. In addition, some people use mature papaya pulp as a thickening agent for cosmetics such as vanishing creams, shaving creams and shampoos and ointments.
1. Papaya is suitable for patients with chronic atrophic gastritis, mothers who lack milk, rheumatism, muscle pain, bruises and sprains, indigestion, and obese patients.
2. Papaya is not suitable for pregnant women and people with allergies.
Papaya seeds are disinfected with 70% thiophanate-methyl wettable powder 600 times solution, washed after 20 minutes, and then soaked with 1% sodium bicarbonate solution for 5 hours, after washing, soaked with clear water for 24 hours, in a constant temperature and humidity box at 36℃ Undertake germination. Sow until the seed coat is white.
Sowing from mid-to-late October to early November. Sow 2~3 seeds per nutrition bag on the surface of the bag and cover it with a layer of nutrient soil after sowing. Then pour plenty of water, cover with a film, and control the temperature between 30-40℃. After the papaya seedlings are arched, the temperature of the seedling shed should be controlled at 20~30℃. The seedling period is about 3 months.
Always keep the soil moist after sowing. When papaya seedlings grow 2 to 3 true leaves, reduce the water appropriately, and the optimum temperature in the seedling shed is 20-25°C. Start fertilizing when 4 to 5 true leaves are drawn, spray 0.2% potassium dihydrogen phosphate and urea, once a week, alternate sprays, spray 3 times in a row, and start to gradually refine the seedlings. Spray fungicide and insecticide once before refining seedlings to prevent pests. When 7 to 9 true leaves grow, and the seedling height is about 20cm, it can be planted.
1. Site selection and site preparation
Choose plots with fertile and loose soil, shelter from wind and sunshine, and good drainage and irrigation.
When planting, remove the nutrient bag, do not loosen the nutrient soil mass, and do not damage the roots. It should not be too deep when planting, and the soil layer should be slightly higher than the root neck. After planting, water enough root water and cover the tree tray with dry straw. Pay attention to frequent watering to keep the soil moist.
The suitable temperature for growth and development of papaya is 25~32℃, and the starting temperature of growth is 16℃. When it is lower than 12℃, the growth basically stops, and it will suffer from cold damage when it is lower than 6℃, and it will die at 0℃. The temperature above 35°C affects the development of flowers, tends to male and causes flower and fruit drop. The suitable temperature for papaya seed germination is 30~32℃, lower than 23℃ and higher than 40℃ is not good for germination.
Papaya tree body growth and fruit development require a lot of nutrients. It is sensitive to nutritional conditions and has obvious symptoms of cable deficiency. In addition to N, P, K, and Ca, it also requires Mg, Fe, B, Mn, and Cu. , Zn and other trace elements. Papaya is a K-loving plant, so it is important to apply K fertilizer in its production. Papaya lacks B and is prone to tumor diseases.
The growth and development of papaya require sufficient and even water supply. Moist soil without accumulation of water is the guarantee of high yield, stable yield and high quality. Insufficient soil moisture, slow plant growth, slender stems and leaves, poor flowering and fruit; too much moisture, poor root ventilation, will cause rotten roots and dead seedlings.
Papaya is a kind of clean fruit tree that requires high air quality. In greenhouse cultivation, due to the limitation of ventilation conditions and the need for winter heat preservation, the air quality in the greenhouse is generally not very good. If improper fertilization produces ammonia, The soot produced by heating with coal in the cold season or due to excessive concentrations of air pollutants SO2, HF, and nitrogen oxides will cause leaf disease. Therefore, greenhouse cultivation should pay attention to ventilation to avoid harmful gases in winter and spring. Accumulate damage. If the greenhouse needs to be heated in winter, try not to use coal.
Papaya has high requirements for light, strong light, strong plants, thick rhizomes, short internodes, wide and thick leaves, thin stems, long internodes and petioles, thin leaves, underdeveloped flower buds, and less fruit set under insufficient light conditions. , The fruit is small. Lack of light when the fruit is ripe will affect the fruit quality. Therefore, high-yield and high-quality cultivation are best to choose sunlight greenhouse cultivation with good light conditions. In solar greenhouse cultivation, the shed film can be uncovered from June to September and transferred to open-air cultivation to enhance light and reduce the temperature. However, in the high temperature and strong light season in July and August, proper shading should be considered to prevent the fruits from being sunburned.