Origin and distribution
Pineapple originated in Brazil in South America and was domesticated by Indians a long time ago, from which excellent seedless edible varieties were selected. This kind of fruit was discovered in 1493 when Columbus visited America for the second time. By the16th century, tropical countries introduced them one after another. Asia was first introduced to India by the Portuguese (1550), and then to the Philippines and Indonesia. In China, pineapple seedlings were brought to Macau by Portuguese at the beginning of17th century (1605), and then introduced to Fujian and Taiwan Province provinces from Guangdong. Pears are described in Guangdong's "Dongguan County Records" (163) and Guang's "Tailue" (1687). The largest number of pineapples are planted in Taiwan Province Province, China, followed by Guangdong, Guangxi, Fujian and Yunnan.
There are more than 60 tropical countries and regions that grow pineapples in the world, with Thailand, the United States, Brazil, Mexico, China, the Philippines and Malaysia as the most, and countries such as C? te d 'Ivoire, Kenya, Indonesia, Ecuador and Bangladesh are also major exporters. Pineapple production has developed rapidly, and the world total output 1988 has reached1063+00000 tons.
Features and characteristics
The plant is about 1 m high, and the stem is solitary and erect, usually covered by long sword leaves. The top of the fruit is covered with crown buds, and there are sucking buds at the base of the stem, which often grow buds. There are many roots in the underground and aboveground stems of pineapple, and even there are many aerial roots growing in the axils of buds. After contacting with soil, aerial roots form underground root groups. Roots can be divided into coarse roots, branched roots and fine roots, all of which are fibrous fibrous fibrous roots. Fine roots are hairy, and mycorrhiza grows at the ends of various roots, which helps to absorb mineral nutrients and water. Aerial roots can absorb moisture and nutrients in the air. The stem is a white cylinder, the underground part is slightly thinner and there are adventitious roots around it; The aboveground part is tightly wrapped with overlapping leaves. The top is the growing point, and after the leaves are constantly divided, the flower buds differentiate to form inflorescences. The aboveground stems are generally 2 ~ 3.5 cm thick and 20 ~ 30 cm high. The leaves are long and narrow, sword-shaped, leathery, of medium thickness, with thin edges, bent upward into a groove, with purple stripes on the surface and silvery white hairs on the light green back; Most varieties have small thorns on the leaf edge; The number of leaves varies with varieties, about 30 ~ 60 leaves per plant, all of which are spirally clustered upward from the base of the stem; The length of leaves varies from 40 to 90 cm. The inflorescence is a head inflorescence, which is drawn from the leaves at the top of the stem and looks like a pine cone. The inflorescence consists of 100 ~ 170 florets. Usually, the florets at the base open first, then open upward in turn, and the whole flower will open in about 15 ~ 30 days. The flower is complete, sessile, with white petals at the base, purple at the top, 6 stamens, pistil 1, 3-lobed stigma, 3-loculed ovary and red bracts outside. Flowers turn green after withering, and fruits turn red and yellow when ripe. The arrangement of small flowers is also spiral. The fruit is located at the top of the aboveground stem, and it is a pinecone-shaped compound fruit, which is made up of many small flower buds, sepals, ovaries, styles and total pedicels (the base of ovary and floral axis tissue form pulp). It takes about 120 ~ 180 days from flowering to fruit ripening. The flesh is yellowish white or golden yellow, crisp and juicy. Pineapples are self-sterile, so they have no seeds. Only through artificial pollination between different varieties can seeds be produced. Seeds are born in fruit orders (small fruit cavities) and are as small as sesame (see figure).
Pineapple leaf trough can collect rainwater and dew, and back hair and aerial roots can absorb water in the air; The stomata of leaves are closed during the day, and the transpiration water consumption is only 1/3 of that of citrus, which has strong drought tolerance. Its photosynthesis is special, which is called the photosynthetic pathway of Sedum (CAM for short), that is, it opens the stomata at night, absorbs CO2 and stores it, and releases it during the day for photosynthesis.
Pineapple is native to the tropics, likes warmth and avoids frost, and is most suitable for areas with an annual average temperature of 24 ~ 27℃. If the average temperature in June 5438+ 10 is above 10℃, the annual average temperature is above 210℃, and there is occasional short-term frost in winter, the south subtropical zone can safely overwinter and can still be used for economic planting. Pineapple needs more calories to blossom and bear fruit, so the southern producing area of China mainly stays in Xia Guo. The choice of soil is not strict, sandy loam is the most suitable, and heavy clay and fine sand can only be planted after improvement.
Variety type
Pineapple varieties can be divided into three types. About 60 ~ 70 varieties.
Kane class
It is the most planted variety in the world. This plant is taller. The leaves are hard and straight, with many spineless edges and a purple ribbon in the middle of the groove. The fruit is large, single crown, long and tubular, shallow, with high edible part, suitable for processing, but light in flavor. Less budding, late budding. The varieties planted in China include Cayenne, Sarawak and Shiloh.
Queens district
The growth is moderate. The leaves are wide, with obvious color stripes in the middle and thorns on the edge. The fruit is large, cylindrical or slightly conical, with orange flesh, tender meat, less fiber and strong fragrance. But the fruit flavor is very deep, and it takes a lot of time to make canned food. The varieties planted in China are Paris Comte and Huangmaurilius.
Spanish class
This plant is very tall. The leaves are long and wide, and most varieties have red thorns on their leaves. The leaves are yellow-green, with red ribbons on both sides. At most, the fruit will grow a compound crown bud. The fruit is medium-sized, with yellowish or orange flesh, more fiber, less juice and strong fragrance. It was introduced to China earlier, so Guangdong Province called it a native species, and Fujian Province called it a local thorn. The varieties planted in China are wild Cain and red Spanish.
In addition, there is a triploid variety Cabezona in Puerto Rico. Its fruit is huge, reaching 6-7 kg, and its flesh is yellowish and fragrant, but it bears fruit late. The tetraploid variety is the queen of Jame, with large fruit and late flowering.
Key points of cultivation techniques
Pineapple often uses plant meristem buds for asexual reproduction. The maturity of offspring cultivated with crown buds is the same, and Cayne species absorbs fewer buds, so it is often used as seedlings. Soil species is not suitable for breeding offspring because of its many crown buds. The offspring of sucking buds bear early fruits, which are often used as seedlings by queens and Spaniards. In the 1970s, China and Guangdong promoted the seedling raising by cutting leaves, which was beneficial to the propagation of improved varieties and improved the propagation coefficient of seed buds (a leaf with leaf buds can be planted after 8 months of accelerating germination, and a crown bud or suction bud can be cut into 15 ~ 20 seedlings). In the late 1970s, various pineapple producing countries adopted tissue culture to produce seedlings in factories.
Pineapple orchards should be planted on slopes facing south, with ditches built on gentle slopes and ridges planted on steep slopes. Close planting can improve the yield and prevent the fruit from being burned by the scorching sun. About 36,000 plants are planted in Cayne per hectare, and the number of medium-sized plants such as Bali can be increased to 50,000. It can be planted in southern China in spring and autumn. Sufficient base fertilizer should be applied when planting. Fertilization is mainly based on bud-promoting fertilizer in early spring, strong fruit fertilizer in early summer and strong bud fertilizer after fruit. Pay equal attention to nitrogen and potassium before flowering, apply more potassium fertilizer after flowering, and spray urea 2 ~ 3 times outside the roots during fruit development. The garden is covered with black film or planted with green manure during the intermission to keep warm and moist. Irrigation during drought; The accumulated water should be drained as early as possible to maintain normal growth. Under the condition of close planting, after harvesting 3 ~ 4 times in pineapple orchard, the fruit becomes smaller, so it is advisable to turn green manure once and plant pineapple again.
In order to promote the rapid growth of fruit, when the crown bud grows to 3 ~ 5 cm, the growing point of Lianxin leaf is dug up, and the buds on the fruit base and fruit stalk are also removed in batches. In addition to those selected for subculture, sucking buds are selected for seedlings. In order to make the fruit mature consistently and harvest the fruit early, after the plant grows 30 ~ 35 big leaves, 250 ~ 500 ppm ethephon (about 30 ml per plant) can be injected into the heart leaves to accelerate germination, and the germination rate can reach over 90%. Naphthacetic acid and calcium carbide can also promote flowering, but the effect is poor.
Pineapple is planted in South Asia. In winter, leaves should be tied to prevent cold, and in case of cold rain, film should be covered. If it is frozen, it should be cultivated and fertilized in time to promote rapid recovery. The main pests and diseases are Fusarium wilt caused by mealybug and heart rot caused by poor drainage. Prevention and treatment are mainly to eliminate the source of disease. Black rot fungus often permeates with rain, so bud digging should be carried out on sunny days to avoid infection. Pests include grubs, crickets, Cao Meng and voles, so we should prevent and treat them as early as possible.
economic value
Pineapple is famous for its unique flavor and high nutritional value. It is one of the four tropical fruits. In the international market, besides fresh fruits and canned food, pineapple juice, frozen pineapple pieces and all kinds of drinks mixed with pineapple juice are very popular. The fruit contains bromelain, which can help the human body digest and absorb protein. Bromelain, citric acid and high-grade starch granules can be extracted from the leftovers of canned fruit juice. There are many frost-free areas in southern China, and the development of pineapple production has broad prospects. In 1980s, peeled pineapples were popularized and welcomed by consumers, which opened up a new way for fresh pineapples.