Name: Hand-shaped rhubarb – rhubarb palm (growing and cultivation)
Palmate rhubarb Rheum palmatuni L. var tanguticum Maxim.
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Synonym: Tangut rhubarb.
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Description. A large perennial herbaceous plant from the buckwheat family (Polygonaceae), up to 2 m high, with a thick short rhizome and succulent large roots. Stem weakly leafy, glabrous, hollow inside. Basal leaves are large, up to 0.75-1.5 m long (together with petiole); blade length 80 cm, width 75 cm. Separate leaves with pinnately cut lobes. Stem leaves are alternate, ovate, with a dry membranous bell at the base. From the second-30% of its year of culture, rhubarb develops large paniculate branched inflorescences. The flowers are small, regular, white, green or pink. The fruit is a trihedral nutlet of red-brown color. Weight of 1000 seeds 1315
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Medicinal raw materials: roots.
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biological features . Palmate rhubarb is a moisture-loving plant that requires fertile soils with good structure. It does not grow well in dry areas. However, even in conditions of excessive humidity, this type of rhubarb often dies. The ground part of the plant dies off annually in winter, and grows back in spring. The duration of development before obtaining seeds is two to three years. For medicinal purposes, the roots of three or four years of age are dug out. In the same place, palmate rhubarb grows for 12 or more years.
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Habitat. It grows in mountainous, forested areas at an altitude of 2000 m above sea level, in mountain forest ravines, on moist and humus-rich soils.
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Distribution . Under natural conditions, it is found in the northern provinces of the PRC (Gansu and Shanxi), the Mongolian People’s Republic and Tibet.
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Back in the 13th century, the famous Venetian navigator Marco Polo was the first European who visited the country of Tangut and described the collection of rhubarb, and in 1871-1873. the outstanding Russian traveler N. M. Przhevalsky collected seeds and roots of palmate rhubarb in the mountainous areas near Lake Kokunor and donated them to the St. Petersburg Botanical Garden. From the imported seeds, plants were grown at first only in botanical gardens, and then under production conditions.
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Currently, rhubarb is successfully cultivated in the western regions of Ukraine, in Belarus, the Voronezh and Moscow regions, and Western Siberia.
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Composition of active substances. The roots and rhizomes of palmate rhubarb contain glycosides of 2 main groups: tannoglycosides (from 7 to 11%) and anthraglycosides (36%). The first group includes glycogallin, tetrarin, the second group includes chrysophanein, reochrysin. The active ingredients are also chrysophanoic acid, reumemodin and rhein.
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Application. Preparations obtained from the rhizomes and roots of rhubarb are used as a means of regulating the activity of the gastrointestinal tract, and as a special laxative for babies.
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Tannoglycosides contained in the roots of the plant have fixing properties, and anthraglycosides, increasing intestinal motility, have a laxative effect. In small doses (0.050.2 g) rhubarb acts on the intestines as an astringent, in large doses (0.51.0 g) it increases the peristalsis of the large intestine, causes a laxative effect (after 810 hours after taking). In addition, rhubarb is part of a choleretic tea (a mixture of immortelle flowers 3 parts, yarrow herb 5 parts and rhubarb root 2 \\ t parts). A tablespoon of this mixture is brewed in a glass of boiling water and drunk at night with cholelithiasis. Children are given rhubarb syrup, half a teaspoon at a time.
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Rhubarb is consumed in the form of tablets, powders and extracts.
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Agricultural technology of cultivation . Site selection. The most favorable for the cultivation of rhubarb are chernozems with a light mechanical composition, structural fertile garden-type soils, protected from northern winds, with a deep arable layer, and calcareous soils of drained peatlands.
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The best predecessors are considered to be clean and busy fallows, row crops and winter fertilizers.
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Soil tillage . The main autumn plowing for plowing is recommended to be carried out at a depth of 2730 cm. If the field is after grain crops, then three weeks before plowing, the stubble is peeled. If the soil has become very compacted during the winter, the field is plowed to a depth of 1416 cm. Otherwise, instead of plowing, the field is cultivated to a depth of 810 cm.
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Application of fertilizers. Under deep plowing, depending on the fertility of the soil, from 40 to 80 t / ha of manure are applied along with 38 centners / ha of superphosphate. If there is not enough manure on the farm, it is brought in equally with the required amount of mineral fertilizers.
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Reproduction. Rhubarb is grown by sowing seeds directly into the ground in early spring, late summer or late autumn.
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The seeding rate in spring is 78, and in autumn 910 kg/ha.
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Plantation care consists in loosening row spacings, weeding and replanting seedlings in sparse places. The first ball is carried out as soon as shoots appear. During the summer, three or four more row spacings are shuffled and rows are weeded two or three times.
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The first top dressing is carried out mainly with mineral fertilizers at the rate of 30 kg/ha of active substances (nitrogen, phosphorus and potash). During the second top dressing, 2
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3\tt/ha of slurry and 1 centner/ha of superphosphate.
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Harvest. Rhubarb is dug up by tractor plows without mouldboards at 30%-fourth year of cultivation in August-September. Rhizomes and roots are cleaned from the ground and washed, the aerial part is cut off, damaged pieces are cut out. Whole roots and rhizomes are cut into large pieces up to 15 cm long, 34 cm thick and laid out under a canopy or in the attic for three to four days for preliminary drying.
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Growing seeds . Rhubarb gives the highest seed yields from the fourth to fifth year of the crop. For growing seeds, it is better to allocate special flat areas with light and fertile soil, protected from cold northern winds. Agrotechnics of cultivation and care of the plantation are the same as for commercial crops of rhubarb, but the feeding area must be 70×70 cm.
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The plant blooms from about the second half of May until the end of June, and the seeds ripen in early July. To avoid contaminating Rhubarb palmate with other rhubarb species, likely due to cross-pollination, it will be necessary to remove plants of other species before flowering. The average seed yield with good care is within 810 c/ha (Perenko, 1946).
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Drying. They are finally dried in a fire dryer at a temperature of 60 ° C. When the moisture content of the roots reaches 12%, drying is stopped. In good weather, you can dry in the open air, hanging the roots on twine (in the shade), and in attics under an iron roof.
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Pack. The roots are packed in wooden boxes lined with paper inside, or in double bags of 2025 kg.
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Storage. Dried roots will need to be stored in tightly closed boxes or boxes to avoid damage by pests of agricultural plants, yellowing and loss of commercial qualities due to their high hygroscopicity.
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quality requirements. The finished raw material should consist of well-dried dense pieces of roots and rhizomes 0.44.0 thick, up to 5 cm long. The root should be brownish-yellow, white in a break with a red-orange speck. The smell is pleasant, specific, characteristic of rhubarb; taste bitter, astringent.
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In accordance with the State Pharmacopoeia X, the following is allowed in raw materials: moisture 12%, total ash 8, ash insoluble in 10% hydrochloric acid, 1; broken parts of rhubarb passing through a sieve with holes with a diameter of 3 mm, 5; pieces blackened at the break 5; organic and mineral impurities 0.5 each, extractive substances not less than 33%.