High-yield cultivation techniques of rhubarb

Rhubarb, alias Grand General, fragrant rhubarb, horseshoe yellow, southern rhubarb and so on. It is a perennial herb of Polygonaceae. Using underground rhizome as medicine has the effects of purging heat, removing blood stasis, antibacterial and anti-inflammatory. Main treatment of hot constipation, delirium crazy, food accumulation ruffian, damp-heat jaundice, blood stasis amenorrhea and other diseases. It has remarkable curative effect on constipation, acute appendicitis, intestinal obstruction, suppurative dermatosis, burn, virus infection, hepatitis and vasculitis. Mainly produces Qinghai, Gansu, Shaanxi, Sichuan and other provinces. Now there are introduction and cultivation in various places.

Morphological characteristics 1. Palm leaf rhubarb is a tall perennial herb, about 2 meters high. The rhizome and roots are thick and yellowish brown. Stem erect, smooth glabrous hollow. Basal leaves have a long, fleshy stalk, ca. as long as leaf blade, leaf blade broadly ovate or suborbicular, up to 40 cm in diameter, palmately cleft, lobes 5 (7), each lobe sometimes pinnatifid or coarsely dentate, base slightly cordate, upper glabrous or sparsely papillose, below pilose; cauline leaves smaller, alternate, shortly stipitate; Ocrea sheathlike, membranous, densely pubescent. Panicle large, terminal, flowers small, several clustered, purplish red or reddish purple; pedicel slender, articulated in middle and lower part; tepals small, 2-whorled, inner whorl slightly larger, elliptic; stamens 9, anthers slightly exserted; styles 3, stigma capitate. Fruit branches gather together, achenes have 3 edges, winged along the edges, apex retuse, base slightly heart-shaped, brown.

2. Zhaogu extra-large yellow perennial tall herbs, about 2 meters high. The shape is similar to that of rhubarb, except that the leaf of this species is palmately parted, with 3-7 lobes; the lobes are pinnately parted, lobules narrow and long, linear-lanceolate.

3. The medicinal rhubarb is similar to the palm leaf rhubarb, but the leaves of this species are shallowly lobed, showing large teeth or broad triangles, and the flowers are also larger, yellow and white, and the buds are oval. The fruit branches spread out.

First, growth habits rhubarb like cold, humid and cool climate, fear of high temperature, avoid continuous cropping. Soil requirements: the soil layer is deep, loose and fertile sandy loam rich in organic matter is better.

Second, soil preparation and fertilization select fields with high topography and good drainage, and cultivate them carefully. Combined with soil preparation, apply sufficient basic fertilizer: 3000 kg of soil miscellaneous fertilizer, 20 kg of urea and 50 kg of phosphorus and potassium fertilizer per mu. Then make beds and wait for sowing.

Third, sow rhubarb and propagate with seeds. It is divided into two steps: seedling raising and transplanting. The sowing time is divided into spring sowing and autumn sowing. Spring sowing before and after the Qingming Festival and autumn sowing around the Beginning of Autumn. The seeds are picked and sown with ripeness. Before sowing, the seeds are spread evenly into the ditches by making a shallow trench on the finished border surface with cymbals. Cover soil seeds and water to preserve soil moisture to facilitate seedling emergence. The sowing rate is 5 kilograms per mu. The suitable temperature after sowing will be able to emerge in about a week. After the rhubarb sprouting, strengthen the management, grow one year later can transplant. When transplanting, the rhubarb seedlings were planted on the whole border according to the row spacing of 70 × 50 cm. Water to preserve moisture in order to survive.

Fourth, after the field management of rhubarb seedlings, attention should be paid to ploughing and weeding to ensure that there are no weeds on the border surface. If planting on a large scale, herbicides should be used to treat the soil before seedling, which can effectively control all kinds of weeds. Water in time in dry weather, pay attention to drainage in cloudy and rainy weather. The Beginning of Autumn should be fertilized once before and after: 20 kg urea and 10 kg potassium dihydrogen phosphate per mu. Rhubarb is easy to bolt and blossom in 2-3 years after transplanting. In addition to seed planting, the flower moss should be removed as soon as possible to prevent nutrient consumption.

5. Prevention and control of diseases and insect pests the main diseases of rhubarb include root rot, which can be controlled with Bordeaux solution of 1-100 Bordeaux before the disease occurs. Or use 65% mancozeb in the early stage of the disease. Downy mildew is prevented and treated with aluminum ethyl phosphate or carbendazim at the initial stage of the disease. The main pests are aphids which can be controlled by aldicarb. Control of underground pests with zinc parathion and poison bait.

Harvest and processing of rhubarb is generally in the autumn of 3-4 years after planting, and the seeds are harvested in time after maturity. When harvesting, first cut off the aboveground stems and leaves, and then dig out the underground roots. Clean the soil, dry it and sell it as medicine. The yield is 500 kilograms per mu.