I. Efficacy of Radix Isatidis Its root is Radix Isatidis, which contains glucosinolate, indirubin, B- sitosterol, adenosine, palmitic acid and various amino acids. Folium Isatidis is rich in mineral elements, vitamins and various nutrients. Contains at least 17 amino acids, 7 of which are essential amino acids for human body; The contents of total sugar, glutamic acid, VB2 and potassium are high. Its roots and leaves can be used as medicine, which has the effects of clearing away heat and toxic materials and cooling blood. Taking root as medicine has the functions of clearing away heat and toxic materials and cooling blood. Indications: viral cold, tonsillitis, mumps, Japanese encephalitis, acute infectious hepatitis, sore throat. Its leaves are called Folium Isatidis, which has the same function as roots. Leaves can be used as a health-care vegetable and can strengthen the body when eaten. Large planting area, long harvest period, high yield and considerable economic benefits.
How to eat: 1. Folium Isatidis: After cleaning, cut into small pieces, blanch in water for 6-7 minutes, take out, soak in cold water for 3-5 minutes, pour off the water, add garlic, salt, vinegar and other seasonings and mix well to serve. It can be fried or cooked with meat. 2, Banlangen: mainly medicinal, you can also drink a little soaked roots, or a small amount of pickled food.
Dietotherapy: Banlangen tastes bitter and cold; Heart, liver, lung and stomach meridians; It has the effects of clearing away heat and toxic materials, cooling blood and relieving sore throat, and is mainly used for treating headache, fever, sore throat, macula, parotitis and other diseases. Isatis indigotica has broad-spectrum antibacterial effect in vitro, which is a traditional Chinese herbal medicine with antibacterial, anti-inflammatory, analgesic and antipyretic effects. In addition, Radix Isatidis contains a variety of antiviral substances, which have a strong inhibitory and killing effect on the virus.
Key points of cultivation techniques 1, land selection and soil preparation
Choose sandy loam with flat terrain, good drainage and loose fertility, and dig more than 40cm deep in autumn, the deeper the better. Combined with soil preparation, 5000kg of decomposed chicken manure and 50kg of compound fertilizer were put into the soil as base fertilizer, and then leveled and raked, and the north-south high border with a width of 70cm was made from the end of March to the beginning of April of the following year. Drains 40 cm wide were dug on both sides of the border to prevent water accumulation.
Step 2 sow seeds
In early April of spring sowing, when the ground temperature reaches 4~5℃, you can sow. When sowing, ditch in the border with a row spacing of 25 cm and a ditch depth of 3 ~ 4 cm. Then, water is poured into the furrow, and the seeds can be planted after the water soaks. After sowing, the soil is covered with a rake, and seedlings can emerge in 5 to 7 days. The seed dosage is about1.5 ~ 2kg/mu.
3. Tian Tuan management
(1) thinning seedlings. When the seedling height is 8~ 10cm, the planting density can be appropriately increased by using both herbs and vegetables, and the seedling spacing can be kept 3cm.
(2) intertillage weeding. Weeding combined with thinning for the first time, and then keeping the field free of weeds according to the field conditions. Stop intertillage weeding after the ridge is closed.
(3) topdressing. After applying sole fertilizer, there is basically no need for topdressing until the first leaf picking. After each leaf picking, topdressing compound fertilizer 1 times, the dosage per mu 10 ~ 15 kg, and adding 5 ~ 8 kg of urea to promote new leaves.
(4) Water and drain pipes. In case the weather is dry after sowing, water it in time to keep enough water. When there is too much rain, ditch drainage should be cleaned in time to prevent water accumulation in the field.
4, pest control
(1) Downy mildew. Mainly harmful to leaves. At the early stage of the disease, white or grayish white mold was produced on the back of leaves, and there were no obvious lesions and symptoms. With the aggravation of the disease, pale green spots appear on the leaves, and the leaves die in severe cases. Prevention and control methods: ① Clean up the site after harvest and burn and bury the diseased branches and leaves centrally, which can reduce the source of overwintering diseases; (2) Reduce the field temperature, drain the accumulated water in time, improve the ventilation and light transmission conditions, and harvest the leaves in time; ③ At the initial stage of the disease, spray Antaisheng solution 600 times, every 7 ~ 10d/time, and spray it continuously for 2 ~ 3 times.
(2) The rainy season is easy to occur, which makes the roots rot and leads to the death of the whole plant. Prevention and control methods: ① Drain water in time, pull out the diseased plants in time, and sprinkle quicklime on the diseased spots or roots of the diseased plants; ② 70{bf} thiophanate-methyl (1000 times) was used at the initial stage of the disease.
(3) Pieris rapae: the adult is a white butterfly, which usually lays eggs on the leaves of Isatis indigotica, and the larvae bite the leaves, causing holes and nicks, and in severe cases, only leaves veins. Prevention and control methods: At the initial stage of damage, 200~250g/ mu of biological pesticide BT emulsion or 800 times of 90{bf} trichlorfon can be sprayed, and it can be sprayed 2~3 times every 7 ~10d/kloc-0.
(4) Liriomyza sativae: Parasitic in leaves, the leaves are destroyed into irregular curves, and the whole leaves turn green seriously. Prevention and control methods: At the initial stage of the damage, 1.8{bf} avermectin EC 2000 times solution or 1000 times solution or 1.8{bf} beta-cypermethrin EC can be used for prevention and control, and sprayed 2-3 times every 7 ~ 10d.
5. Harvest and processing
Folium Isatidis: When the leaves grow to 10~ 12cm, cut them from the base of the plant 2cm above the ground. Spring sowing can be harvested 4-5 times from early May to the middle and late period of 10. The remaining vegetables can be spread out, dried to 70% to 80%, and tied into small bundles.
Banlangen: In the middle and late June, 10, when the upper stems and leaves turn yellow, dig roots. First, open a ditch with a depth of 60cm on one side of the furrow, and then carefully dig along the front to avoid root injury or root breakage. After being shipped back, remove the soil and stems and leaves, wash them, dry them until 70% to 80% dry, tie them into small bundles, and then dry them until they are all dry, which can be dried in rainy days.