Roselle is an annual herbaceous plant of the Malvaceae family. The leaves and calyces are used as medicine. Widely distributed in tropical and subtropical regions. It is cultivated in Taiwan, Fujian, Guangdong, Guangxi, Yunnan and other provinces and regions in my country. It tastes sour and is cold in nature. It has the functions of lowering blood pressure, diuresis, relieving cough, detoxifying, and promoting bile secretion. It is used abroad to treat hypertension, arteriosclerosis and neurological diseases. Natural food pigments can be extracted from the calyx, which is a raw material for medicine, beverages and food.
1. Plant morphological characteristics
Plant height is 1.5 to 2 meters. Stem lavender, hairless. The leaves are alternate; the petiole is 2 to 8 cm long, the stipules are linear, sparsely villous; the lower part of the stem is oval but not divided, the lobes are lanceolate, 2 to 8 cm long, 5 to 15 mm wide, the apex is printed or gradually Pointed, rounded to broadly wedge-shaped base, serrated edges, hairless on both sides, 3 to 5 main veins, and glandular ribs below. Flowers solitary in leaf axils, nearly sessile; bracts 8 to 12, red, fleshy, lanceolate, sparsely covered with long bristles, with spiny appendages at the proximal end, and the base is connate with the calyx; the calyx is cup-shaped, purple-red, Sparse coarse hairs and spines, 5 lobes, triangular lobes, 1 to 2 cm long, 5 petals, yellow, the base is connate with the stamen column, the inner base is dark red, 6 to 7 cm in diameter; there are many stamens, and the filaments are connected to form a column; seeds There are 5 rooms and 5 styles. The capsule is ovoid, 1.5 cm in diameter, densely covered with coarse hairs, and has 5 petals. There are many seeds, kidney-shaped and hairless.
2. Requirements for environmental conditions
Like warmth, fear cold, and early frost. Grows in hills and flatlands south of 30 degrees north latitude and below 600 meters above sea level. It is not suitable for cultivation in cold mountainous areas. It likes full sun and is a short-day plant. It prefers full sunlight under long day conditions, and it can only grow but not produce buds or bear fruit.
3. Cultivation technology
1. Variety type
It can be divided into two types according to the harvest period:
①Early maturing type. The plants are shorter, 1.0 to 1.5 meters high. Strong branching ability and low branching site. The branches are thin and soft, and the plant shape is loose, so it is not suitable for dense planting. The calyx is red, the sepals are thin, the fruit is slightly smaller, and the number of fruits per plant is more than 130. It has strong cold resistance, requires a large amount of fertilizer, and has poor drought tolerance. Suitable for cultivation in areas with early first frost.
② Late maturing type. The plant height is about 2.0 cm, with mainly one-time branches. The branches are thick and hard, and the plant type is compact, suitable for dense planting.
The calyx is deep purple-red, the sepals are thick, and the fruits are larger. The number of fruits per plant is about 120. It has a well-developed root system, is resistant to drought and thinning, and has weak cold resistance, so it is suitable for planting in mountainous areas.
2. Site selection and preparation
It is advisable to choose sandy loam that faces the sun, has a deep soil layer, and has good drainage. Apply 2,000 kilograms of decomposed manure or compost per acre as base fertilizer, and turn it over after application. Plow, harrow and level.
3. Propagation
Reproduce by seeds.
Sow seeds from late April to early or mid-May. On a sunny day after rain, open holes 1 meter × 1 meter apart between rows, 10 to 15 centimeters wide and 10 centimeters deep. Sow 4 to 5 seeds on demand in each hole, with a sowing depth of 3 centimeters, covering with soil 0.5 to 1 centimeters, and the seeding rate per acre. About 0.6 kg. Seedlings emerge about a week after sowing. Thin out seedlings with a height of about 15 cm, leaving strong seedlings in each hole.
4. Field management
The seedlings are 15 cm high, thinning and patching. The plant height is 30 cm, combined with top dressing and soil cultivation, and timely cultivating 2 to 3 times.
In addition to applying sufficient base fertilizer, top dressing should also be applied in a timely manner. For the first time, apply 10 to 15 kilograms of ammonium sulfate per mu during the seedling stage; for the second time, before and after budding, apply 50 to 100 kilograms of decomposed cake fertilizer or superphosphate or 1,000 to 1,500 kilograms of human excrement per mu, and cover with soil after application. . When 70% of the plants have flower buds, remove the tops in time and remove stunted flower buds to promote fruit development.
5. Prevention and control of diseases and insect pests
Root neck rot disease shows yellow-brown sunken lesions. After the lesions expand, the roots and stems will rot, the outer skin will crack vertically, and the internal fibers will be exposed and constricted. It becomes thinner and the whole plant wilts. Prevention and control methods: Soak the seeds with 50% carbendazim 400 times for 10 minutes before sowing; during the onset of the disease, use a mixture of carbendazim 800 times and 500-600 times sterile spray once every 7 to 10 days for 2 to 3 times in a row. .
4. Harvesting and processing
In mid-to-late November, when the leaves are yellow and the seeds are black, cut off the fruit branches, remove the calyx and the fruit, and dry them in the sun for one day, and then remove them after they shrink. calyx.
The calyx should be kept intact and cannot be peeled off separately, and then placed on a clean straw mat or bamboo basket to dry in the sun, or dried at 40°C. The sepal has good color and little loss of content. The dry rate is 10.5:1. Generally, the yield of dried sepals per mu is 50 to 100 kilograms.
After the extracted fruits are exposed to the sun, the outer skin will naturally crack and the seeds will fall out. Dry the seeds and store them in a ventilated and dry place.
Reference: c.gov.cn/datalib/2003/AgroBreed/DL/DL-457805
Original in Africa, it is a Malvaceae plant in tropical and subtropical dry areas. . The plant shape is like grass cotton, upright, more than 1 meter high, with many branches on the main trunk. The flowers bloom in summer and autumn, with a long flowering period. The corolla is yellow, the sepals and accessory calyxes are rose red, and the stems and petioles are often light rose. During the flowering season, , red, green and yellow, very beautiful and cute. It is an economic plant widely cultivated by African people, especially African Arab people and West African people. The calyx seeds, stems and leaves of the plant can be used. The calyx (fresh or dried) has antihypertensive, antiscorbutic and diuretic properties, and has a relieving effect on bronchitis and cough diseases. It is widely used as a drink among African people. The tea brewed by the Arabs from the calyces is called "Sudan tea", and some are also used as natural pigments and seasonings for food. Europeans have long imported dried calyx products from Africa and used them as jelly, flavored refreshing drinks, etc. In addition to having calyx-like medicinal effects, the leaves are used as a cleaning material for abscesses in medical surgery. The leaf juice can also treat cracks on the feet. The epidermis of the stem is one of the main raw materials for rope making by Africans. In recent years, my country has successfully planted it on a large scale in Fujian and other provinces, and more than 200 kilograms of dried calyces can be harvested per mu of land. In addition to being exported, it is also sold in the domestic market. Products such as roselle candies, soft drinks, and juices are popular.
Reference: /page/index806.htm
Planted from April to May and harvested from November to December.
Scientific name: Hibiscus sabdariffaL. Alias: Hibiscus sabdariffa, its English name is "Roselle", it is called "Karkade" in Arabia, and some countries call it "Sorrel" ), "Hibiscus flower".
Roselle belongs to the genus Hibiscus of the Malvaceae family. It is an annual upright herbaceous plant. It is native to Africa and is now widely distributed in tropical and subtropical areas. It is cultivated in southern my country. It was introduced into our province between 1940 and 1945, and is now used for commercial cultivation and production in southern and central Fujian.
Roselle plant height is 1 to 2 meters, with lavender stems and odd-shaped leaves. The lower leaves are oval but not divided, and the upper leaves are palmately divided with three deep lobes. The flowers are solitary in the leaf axils, the calyx is cup-shaped and purple-red, with sparse coarse hairs and thorns, and the corolla is yellow, 6 to 7 cm in diameter. The capsule is ovoid, has many seeds, and is kidney-shaped. It is a short-day plant with strong adaptability, rough growth and tolerance to barrenness and drought. The growth period is about 120 days, planted from April to May, and harvested from November to December. The yield per mu is 80 to 100 kilograms of dried sepals, 95 kilograms of seeds, 80 kilograms of fiber, and 1,900 kilograms of dry stems, with an output value of 1,000 yuan.
The main harvested part of roselle is the calyx. The calyx is purple-red flesh, and the dried sepal contains 3.5% protein, 63.5% carbohydrate (22% organic acid, 16% reducing sugar, 25.5% other non-nitrogen substances), 11% cellulose, and 12% ash. The main component of organic acid is Hibiscus acid. The dried calyx still contains 1.5% anthocyanins.
The corolla is yellow, and its pigments are flavonoid glycosides. The main components are Hibiscitrin-3-glucoside, Gossypifrin-7-glucoside, and Sabdarifrin. ), Quercetin; glycolic acid, citric acid, tartaric acid, oxalic acid, vitamin C (0.99-1.05 mg/100g dried petals).
The seed oil content is 22.7%. The sterols separated from the seed oil contain cholesterol (Cholesterol), campesterol (Campesterol), stigmasterol (Sfigmasterol), β-sitosterol (β-Sitosterol), α -Spinasterol (α-Spinasterol) and ergosterol (Ergos-terol).
Roselle is versatile.
The leaves, petals, and sepals have been used for cooking and medicine in foreign countries for hundreds of years.
Various beverages (such as juice, soda, low-alcohol wine, etc.), jams, jelly, fudge, preserves, etc. made from rosella sepals have come out one after another and have become fashionable foods. The natural food pigment extracted from sepals has beautiful color, strong stability, safety and hygiene, and can replace the artificial rose red pigment imported from the UK. Roselle seeds have a high oil yield, are non-toxic and are edible.
The bark of roselle stems and branches is a good fiber raw material, and its tensile strength is better than kenaf fiber. The polysaccharide content of the woody part is higher than that of bamboo, but the intrinsic content is lower than that of bamboo. The pulp made from this raw material can be used to make high-quality writing and printing paper.