High-quality and High-yield cultivation techniques of Radix Isatidis in Zoucheng City, Shandong Province

High-quality and High-yield cultivation techniques of Radix Isatidis in Zoucheng City, Shandong Province

Radix Isatidis is the dry root of the cruciferous plant Isatis indigotica, and the upper leaf is Isatis indigotica, which is a common traditional Chinese medicine. According to textual research, Radix Isatidis was artificially planted in the Tang Dynasty. At present, the main producing areas of Radix Isatidis are Shandong, Anhui, Gansu, Shanxi, Shaanxi, Inner Mongolia, Heilongjiang and other provinces. In 2017, the Agriculture Department of Shandong Province carried out the construction of an innovative system for the cultivation of traditional Chinese medicine, taking the high-quality and high-yield cultivation technology of Radix Isatidis as the main technical research and development and promotion project, to further improve the technical regulations of high-quality planting management of Radix Isatidis and improve the planting income.

1. Morphological characteristics and growth habits

1. Morphological characteristics

Radix Isatidis is a biennial herb with a height of 50 cm and 100 cm. The root is thick and nearly conical. The root diameter is generally 2.0 cm and 3.0 cm, and the commercial root length is 20 cm and 30 cm. Its surface is yellowish, with short horizontal lines and a few fibrous roots. The florescence is from April to May.

two。 Growth habit

Radix Isatidis has strong adaptability, with the characteristics of like light, afraid of stagnant water, like fertilizer, resistant to severe cold, the requirements for soil are not strict, and the general soil can be planted in cold and warm areas.

II. Site selection and sowing

1. Land selection and land preparation

In order to obtain high quality and high yield, it is appropriate to choose sandy loam soil with good permeability and no stagnant water after rain. The previous crop is the most suitable for planting non-cruciferous crops such as corn, sorghum and sesame. After the previous crop is harvested, clean up the withered branches and leaves in time, destroy them from a long distance or bury them deep in the ground. The land planting Radix Isatidis adopts the twice-a-year tillage system, the first deep ploughing before winter, the principle is only ploughing without raking, through the alternation of freezing and thawing, improve the soil physical and chemical properties, enhance the soil water and fertilizer conservation capacity, and improve the production potential. Through winter ploughing, the occurrence of soil-borne diseases and the base number of overwintering eggs in the field were reduced. The second ploughing is 10 to 15 days before sowing after the beginning of spring. Combined with deep ploughing, 3500 kg of completely rotten farm manure or 4500-5000 kg of edible mushroom dregs were applied per mu, and then ploughed deeply, raked fine and leveled.

two。 Make beds, sow seeds

In order to facilitate management, especially convenient drainage and irrigation, production is mainly to make a flat bed 1.2 meters wide. After being done, 200 kg of lignin fertilizer per mu is applied on the border surface, and then ploughed once deeply. The seeds were soaked and mixed before sowing, and the seeds were soaked in clean water for 12 hours. In order to sow evenly, remove the seeds and dry the skin with oil-free gauze, mix them with sifted fine sand or fine soil and sow them evenly, with a seed amount of 2-3 kg per mu. The sowing of Radix Isatidis is divided into spring sowing and autumn sowing. Spring sowing is from early April to early May, and autumn sowing is generally in early August in southwest Shandong. Spring sowing requires that the soil temperature of 5 cm to 10 cm should be stabilized at more than 12 ℃, and the soil relative humidity should be 60% and 80%. There are generally three ways of sowing: sowing, strip sowing and hole sowing. In order to produce seedlings neatly and reduce labor intensity, strip sowing is better, row spacing is 30 cm, sowing depth is 2-3 cm, and suppression is carried out after sowing to preserve soil moisture.

III. Field management

1. Intermediate seedling and fixed seedling

Combined with weeding, when the height of seedlings is 4cm and 7cm, the distance between plants is 4cm and 6cm. After fixing the seedlings, the plots with poor soil moisture should be watered gently to stabilize the seedlings. Matters needing attention: remove weak and diseased seedlings between seedlings, and take them out of the planting field and bury them deeply.

two。 Weed

In order to ensure the quality of Radix Isatidis and avoid the damage of herbicides to plants, artificial weeding was adopted. When the canopy of Radix Isatidis seedlings sealed the border, only weeding did not loosen the soil, until it withered in autumn.

3. Water and fertilizer management

In the early growth stage of Radix Isatidis, an appropriate amount of drought can promote the root system to set down to a certain extent. From May to June, combined watering was mixed with potassium sulfate compound fertilizer (15-15-15) 20kg / mu and lignin fertilizer 30kg / mu, and then watered after light ploughing. In the southwest of Shandong Province, the upper leaves (Daqing leaves) are generally harvested twice in late June and mid-late August respectively. In order to prevent the effect of harvesting upper leaves on the lower root system (Radix Isatidis), watering and topdressing is done 2-3 days after each harvest, often keeping the soil moist.

IV. Disease prevention and control

1. Main diseases

① downy mildew. The disease mostly occurs from late June to mid-July. In addition to harming the leaves of Radix Isatidis, it can also infect the stems, pedicels and pods of Radix Isatidis. At the initial stage of infection, polygonal or irregular yellow-brown spots appeared on the edge of the leaf surface. When the humidity was high, there was a dense white to gray-white mildew layer on the back of the leaf corresponding to the disease spot, that is, the pathogen zoosporangium. In the later stage of the disease, the leaves dried up, and the damaged stems, pedicels, petals, calyx and pods were brown, and there was a white mildew layer above, which caused the deformation of hypertrophic tissue.

② sclerotiorum disease. The whole plant of the disease was damaged, and the affected leaves were round on both sides, with a diameter of 2-6 cm, slightly sunken, gray-white in the center and brown at the edge; in the later stage, the disease spot became thin and brittle, color fissure or perforation, and brown mildew appeared on it when it was wet, which are the conidiophores and conidia of the pathogen. The old leaves first fell ill and spread from bottom to top. In severe cases, multiple disease spots healed each other, making the leaves withered early.

③ root rot. Root rot is one of the most serious diseases in recent years, which mainly harms the root of Radix Isatidis, the root tip of fibrous root and main root is damaged first, the root epidermis is black at the initial stage of the disease, and the vascular bundles of the root turn brown until the whole root rotates and the aboveground part wilts and the whole plant dies.

two。 Integrated disease control measures

① formula fertilization. Under the condition of meeting the nitrogen demand of Radix Isatidis, the amount of phosphorus and potassium fertilizer and biological bacterial fertilizer should be increased. From late June to early August, in the rainy season in southwestern Shandong, foliage was sprayed with a mixture of 150 times of biological compound fermentation bacteria and 20 times of soybean milk, once every 7 days, 4 times for 5 times in a row to cultivate health.

Plant, enhance the comprehensive resistance of the plant.

② keeps the countryside clean. Remove withered and diseased leaves in time before the rainy season, and bring them out of the planting field to maintain good field permeability and reduce air humidity between rows; prevent stagnant water in the field after heavy rain; clean up the residual branches and leaves in time after the upper leaves are harvested.

③ rotation is reasonable. Generally adopt the rotation system of more than 3 years to avoid rotation with cruciferous crops such as Chinese cabbage, rape, radish and so on.

④ chemical control. Downy mildew, using 72% urea cyanogen manganese zinc (DuPont Kelu) wettable powder 500 times 600 times, or 50% metalaxyl manganese zinc wettable powder 600 times 800 times liquid alternately sprayed on the leaves, once in the initial 7 days, 3 times in a row. In the early stage of Sclerotinia sclerotiorum disease, 500 times liquid of 70% carbendazim wettable powder or 800-1000 times liquid of 40% Sclerotinia sclerotiorum net wettable powder were sprayed once every 10 days, 2 times in succession, with emphasis on the base of plant stem and ground. Before the onset of root rot, 80% thiram water dispersible granules 300 times 400 times, or 50% carbendazim wettable powder 800 times solution, found that the diseased plants were removed in time, and buried or burned at a long distance.

V. Pest control

1. Aphids

It is a stab-sucking mouthparts pest. In addition to sucking the leaves of Radix Isatidis and reducing its photosynthesis, its excreta is very easy to cause the growth of epiphytic bacteria and the decline of the quality of the upper leaves (Isatis indigotica). Adopt the method of hanging yellow board in the field, generally hang a yellow board every 5 meters 2; chemical control uses 6000 times of fenvalerate and 2000 times of imidacloprid wettable powder mixed with foliar spray, or 0.3% matrine water spray.

two。 Pieris rapae

During the whole growth and development period, Radix Isatidis was most seriously damaged by Pieris rapae, and the larvae gnawed on the leaves, forming many small holes or notched holes. Spray control with 45% cis-trans cypermethrin 3000 times or 2.5% doxorubicin (Caixi) suspension 3000 times.

3. Plutella xylostella

Mainly in the spring damage, gnawing leaves. Adults lie dormant during the day and come out at night, hide in the plant bushes during the day, and begin to move after sunset. 3% azadirachtin EC 2000 times or 15% indenyl (hit) suspension 3000 times were sprayed for 2 times continuously for 3 times.

VI. Harvest

1. Radix Isatidis and Folium Isatidis

Before the roots stopped growing and the aboveground leaves withered and the leaves were still green, the harvesting was carried out on a sunny day and mechanized harvesting was generally adopted. Radix Isatidis is chosen to harvest the aboveground leaves on a sunny day before harvest. The method is to cut the leaves 2cm and 3cm above the ground with a sickle. After the harvest of Radix Isatidis, remove the soil, Reed head, stems and leaves, dry them, then tie them into small bundles, dry them, pack or bag them for storage. The roots are straight, sturdy, solid and powdery. In the process of drying, we should often turn over, strictly prevent rain and mildew, and reduce the output of Radix Isatidis. The harvested upper branches and leaves (Daqing leaves) should not be placed in direct sunlight, tied into small handfuls after harvest and hung in a ventilated shed to dry in the shade to prevent dampness and mildew.

two。 Seed harvesting

Select strong disease-free and insect-free plants to be harvested when the pod surface is purplish brown or yellowish brown, sun-dried, and stored in a dry and cool place after removing miscellaneous materials. The lifespan of the seeds of Radix Isatidis is generally two years, and the seeds shall not be sown after two years.