How to grow Isatis Root

Radix Isatidis, alias Isatis indigotica, indigo, is a cruciferous herb, is a traditional valuable Chinese herbal medicine. The root and leaf are used in medicine, the root is called "Banlangen", and the leaf is called "Daqing leaf". The annual demand is very large, according to the national market survey, the annual demand of Radix Isatidis is about 4 million kg, the market prospect is broad. Radix Isatidis is resistant to cold, drought, strong resistance and wide adaptability, and has been planted in the north and south of our country. Especially in recent years, its dosage has increased, the economic benefit has been greatly improved, and the planting area has expanded rapidly. 1 Medicinal value and economic benefit 1.1 Medicinal value Radix Isatidis has the effects of clearing heat, detoxification, cooling blood and so on. It can treat fever, cold, sore throat, mumps and so on. Especially for the prevention and treatment of SARS has a special effect. 1.2 Economic benefit planting Radix Isatidis has high economic benefit. Generally per hectare dry cargo plate 3750~5200kg, dry goods big green leaf 2250~3000kg, the average price of Isatis root and big green leaf dry goods is 4.00 yuan per kilogram, the output value per hectare can reach 2.4 ~ 33000 yuan. 2 main points of planting techniques 2.1 site selection and fertilization 2.1.1 soil selection Radix Isatidis is a biennial herb, which grows on the ground in the first year, bolts in the second year, and the plant height is about 1.2m; the fruit is purple and flat; the root is slender, cylindrical, 20cm long and 50cm long; like warmth, cold tolerance, avoid flooding. When planted on loose soil, the roots are long, smooth and with few forks. Sandy loam and humus loam with deep soil layer and good drainage should be selected for planting. 2.1.2 rational fertilization combined with deep ploughing, farm manure 3000kg per mu. After deep turning, leveling, making beds or ridging, to achieve a deep ploughing layer. 200kg compound fertilizer was applied per mu, and mouth fertilizer was applied when sowing. 2.2.2 seed treatment and sowing methods 2.2.1 seed collection and treatment of Radix Isatidis did not blossom and bear fruit in the first year. When the roots were harvested in the same year, the disease-free, thick, strong and unbifurcated roots were selected for storage. In the spring of the second year, the roots were planted according to row spacing 50cm and plant spacing 20cm, and the seeds were watered in time. In May, the seeds matured, collected and dried, and were reserved for the second year. 2.2.2 sowing time and method before sowing, the seeds were soaked in 40 ℃ warm water for 4 hours, and then mixed evenly with plant ash. Spring sowing is better for planting in the north, and the time is April 20-30. When sowing in ridges, wide seedling band sowing, ridge width 60cm, plant spacing 3~4cm, leaving double-row crutch seedlings, border sowing row spacing 20cm, Jilin Shuangliao agrotechnical extension center plant spacing 7~10cm, 40 ~ 500000 seedlings per mu. When sowing, open a deep ditch of 2cm, spread the seeds evenly in the ditch, cover the soil, step on it once, or gently press it with a razor. The soil moisture should reach 65%-70% of the maximum capacity in the field, and the seedlings should emerge 7-10 days after sowing. 2.3.3.When seedling height 4~7cm, combined with soil loosening and weeding, seedlings were fixed by 3~4cm according to plant distance. After the seedling is fixed, it should be dry rather than wet in the early stage of growth, promote the root to be tied down, and keep the soil moist properly in the later stage of growth to promote nutrient absorption. Pay attention to drainage in the hot and rainy season. 2.3.2 only by shoveling and weeding the loose soil can we have deep roots, few forks and luxuriant leaves. The whole growth period should be shoveled three times: when the seedlings had 3 leaves (the end of May), the first shovel was carried out to loosen the soil, and the depth was 15: 20 cm. One month later (the end of June), the second shovel was carried out, the depth was 20: 25 cm, and the third time before harvest (the end of September). If you use herbicides to control weeds, you can choose "Jingke grass energy". When weeds are 3-5 leaves, 40mL per mu is sprayed on water 50kg. 2.3.3 topdressing and leaf cutting were applied in the first ten days of June, ammonium sulfate 40~50kg was applied per mu, and compound fertilizer 7~15kg containing calcium and magnesium was applied. Under the condition of sufficient water and fertilizer and good growth, the leaves can be harvested twice in late June and late August, leaving stubble high 3~5cm. After each leaf cutting should be timely topdressing, irrigation, do not apply ammonium bicarbonate, so as not to burn the leaves. 2.4 Disease and pest control of Isatis root diseases are mainly downy mildew and powdery mildew, and pests are mainly caused by green worms and peach buds in seedlings. 2.4.1 main symptoms of downy mildew: damage to leaves and petioles. There are yellow and white disease spots on the leaf surface in the early stage, and gray-white mildew on the back of the leaves in the middle and later stages. As the disease progressed, the leaves turned yellow and finally dried up and died. Prevention and control methods: pay attention to drainage, ventilation and light transmission, and avoid continuous cropping or rotation with crops susceptible to downy mildew, such as Cruciferae. During the disease period, 70% mancozeb is sprayed with 100g / mu 50~60kg to control the disease, once every 7 days, twice in a row. 2.4.2 main symptoms of powdery mildew: damage to leaves. From June to July, the disease is easy to occur under the conditions of low temperature and high humidity, too much nitrogen fertilizer, too dense plants, poor ventilation and light transmission. When drying at high temperature, the disease stops spreading. Control methods: no stagnant water in the field to inhibit the occurrence of diseases; reasonable close planting and combined application of nitrogen, phosphorus and potassium fertilizer. At the initial stage of the disease, 65% Fumei zinc wettable powder was sprayed with 300 to 500 times liquid. 2.4.3 Pieris rapae damage symptoms: bite the leaves, light damage leaves into holes, lacerations, heavy eat up all the mesophyll, leaving only veins. Control method: before the 3rd instar, the larvae were sprayed with 800 / 1000 times liquid of 90% trichlorfon. 2.4.4 harmful symptoms of peach buds: adults and nymphs suck the sap of stems and leaves, resulting in yellow wilt of diseased leaves. Control method: spray 40% dimethoate 1000-1500 times or 50% dichlorvos emulsion 1000 times during the occurrence period. (3) after harvesting, processing and storing the roots after the aboveground withered in October, dig the 60cm deep ditch beside the border first, then dig forward sequentially to clean the soil, and when drying to 7: 8, tie it into a small bundle and then dry it thoroughly, that is, the medicinal "Radix Isatidis". The root is long, straight, sturdy, solid and powdery. In the north of China, the leaves can be harvested twice when the seedlings are high in June or August, and the leaves can be dried in the sun as medicinal "big green leaves". Radix Isatidis and Folium Isatidis are generally stored in a dry and ventilated place, with a suitable temperature below 28 ℃, a relative humidity of 65% and 75%, and a safe moisture content of 11% and 13%. Timely sales to achieve economic benefits.