What are the varieties of biennial herbs Radix Isatidis? Which variety is better? When will it be ready?

Radix Isatidis, also known as indigo root, is a common biennial herb in China, which is widely used as medicine because of its heat-clearing and detoxification, cooling blood and pharynx. What are the varieties of Radix Isatidis? Which variety is better? When will it be ready?

Variety introduction of Radix Isatidis:

1. Radix Isatidis: the dried root of Isatis indigotica is slender cylindrical, the surface is light grayish yellow, rough, with longitudinal wrinkles and horizontal marks, and there are root marks, the root head is slightly enlarged, there is a pit at the top, and there are dark green petiole residues around it. Thicker roots and dense verrucous processes and wheel-shaped gray-brown petiole scars. The quality is solid and brittle, the cross-section skin is yellow-white to light brown, and the xylem is yellow. The root is straight, sturdy, solid and powdery.

2. Malan root: it is the dry rhizome and root of the plant Malan, grayish brown, the rhizome is cylindrical, the upper part has a short aboveground stem, the aboveground stem has opposite branches, the rhizome has dilated nodes, and the nodes are divided into thicker rhizomes and slender fibrous roots. The root is slender and slightly curved, with fine wrinkles on the surface. The rhizome and aboveground stem are brittle and easy to break, the cross section is uneven, slightly fibrous, there is a large pulp in the center, and the root is more flexible. The evenness of strip length and thickness is the best.

The efficacy and effect of the above two varieties of Radix Isatidis are good, general pharmaceutical companies use these two kinds of medicine, so when planting, you can choose one kind of planting.

Planting time:

The sowing season of Radix Isatidis is different, the products harvested are also different. According to the sowing time of Radix Isatidis, it can be divided into four stages: autumn sowing, early spring sowing, spring sowing and summer sowing. Autumn sowing and early spring sowing are mostly for the purpose of harvesting seeds, the roots of Radix Isatidis planted in these two periods can not be used as medicinal materials; summer sowing is suitable to be used in the areas with long plum rain season in the south, this method can reduce diseases and insect pests, but the yield is low. Radix Isatidis sown in spring can harvest both leaves and roots, and the yield is higher, so it is the most commonly used method.

Planting techniques:

Raising seedlings

Transplanting perennial roots or sowing seeds in autumn are generally used. The seeds harvested in May and June were sown in early April of the following year. Nursery should choose fertile and loose sandy loam, border width 3.33 meters, height 16.7 cm, unlimited length, border surface should be soft and flat, sowing or strip sowing can be. 1500-2000 kg of farm manure is used as base fertilizer for every 667 m 2 (1 mu). The strip sowing is divided into a shallow trench of 0.33 cm and 0.67 cm at a row spacing of 10 cm to 13 cm. Before sowing, put the seeds in 10% salt water, remove the sclerotia and shrunken grains floating above, then soak them in warm water of 25 ℃ for 24 hours, sprout and destroy the buds, sow after the seeds are white, and compact the soil after sowing. Sowing about 2.5 kilograms every 667 meters. Cover with a thin layer of straw after sowing to prevent the sun, spray water once every morning and evening, keep the seedbed moist, and seedlings can emerge after 6-7 days. The mulch should be removed immediately after emergence. When the seedling height is 1.5 cm to 2 cm, the seedlings should be separated, and the weak will be removed and the strong will remain. When the seedling height is 3-5 cm, leave a strong seedling according to 3-4 cm square, apply a thin human feces and urine, spray 100-fold Bordeaux solution to control downy mildew, and use 500-fold solution of Dysen zinc to control Sclerotinia sclerotiorum at the same time. 50% methyl topiramate or 800-fold carbendazim solution should be sprayed when the disease is found, and the diseased plant should be centrally burned to prevent spread.

Generally, about 30 days of cultivation can come out of the nursery. It is suitable to transplant persistent roots in spring and autumn, and it is suitable for field planting or replanting because of air temperature and humidity.

Colonization

Banlan root straight-root plant, the main root is long, generally can be buried in more than 30 cm. Therefore, it is best to choose deep soil, fertile and loose, leeward to the sun of dry land, sloping land planting, but should not be planted in low-lying places and paddy fields. The suitable time for transplanting seedlings is autumn and spring. Spring frost and snow disappear, the temperature rises, Rain Water is more, and the survival rate is high after planting; the temperature gradually drops in autumn, the climate is cool, and it is easy to survive, but pay attention to drought prevention. Spring sowing and transplanting is a production commodity, and autumn sowing is a reserved seed. The commercial field of Radix Isatidis was transplanted and planted in the first and middle of May. If it is planted in pieces, weeds should be removed, the soil should be loosened, and then the land should be prepared for bed, with a width of 1.5 to 2 meters, a width of 33.3 centimeters, and a height of 16 to 20 centimeters. Every 667 meters, 1500 kilograms of farm mature organic fertilizer was applied, raked fine and leveled, and burrows were dug according to plant spacing of 35 cm to 40 cm and row spacing of 60 cm to 70 cm, with 2 plants in each hole. When transplanting, you should plant with the seedlings, pay attention to the root system stretch, compaction, and pour enough water to fix the seedlings.

Administration and Management

After the colonized seedlings survive, the seedlings should be filled to achieve balanced growth, and thin human feces and urine should be applied once to promote the rapid growth of the seedlings. When the seedling height was about 20 cm, shallow weeding was carried out to remove weeds and fertilizer was applied to grow seedlings, and urea 8kg, superphosphate 20 kg and cake fertilizer 40 kg were applied every 667 m 2. In the first and middle of June, the height of the seedlings is more than 25 centimeters, and the first leaves should be harvested in time. After leaf cutting, 500 kg of quick-acting fertilizer human feces and urine or 5 kg of urea (water application) were applied every 667 m 2 to promote leaf regeneration and rapid growth. The leaves can be cut again in late July and mid-September respectively. The available nitrogen fertilizer should be applied after each leaf cutting, combined with ploughing and loosening the soil. In case of dry weather, it is necessary to irrigate and preserve moisture and moist soil in time to ensure high yield.