How to grow Corydalis saxicola? Detailed explanation of high-efficiency cultivation techniques for Chinese medicinal herbs

Corydalis saxicola is a precious Chinese medicinal herb from the high-cold mountainous areas of Guizhou and Guangxi. Its main medicinal component is corydaline (dehydrocavidine), which has unique antibacterial, anti-inflammatory, analgesic and strong sedative effects. In recent years, the clinical value of Corydalis saxicola has become increasingly high, and the "Corydalis saxicola injection" made from it is often used to treat hepatitis B, hepatitis A and early-stage cancer and other diseases, with remarkable efficacy, and the product is in short supply. To scientifically develop this Chinese medicinal herb resource, from 2000 to 2003 we carried out line domestication and cultivation of wild Corydalis saxicola, all of which succeeded, with an average yield of 78.9 kg of dried herb per mu and an output value of 6670 yuan per mu. Its high-yield cultivation techniques are as follows:

1. Scientific site selection. Wild Corydalis saxicola often grows in limestone crevices at an altitude of 600-800 m, in a shady, cool and rain-scarce growing environment. Therefore, for high-yield field cultivation, shady fertile mountain land or fields should be selected for planting. According to our cultivation trials under different altitudes, sunlight and soil conditions, wild Corydalis saxicola grows better in shady, humid, cool loam or sandy loam with 8-9 hours of sunlight, deep and fertile soil and slight alkalinity, while it grows poorly on barren acidic soil at low altitude with high temperature and strong light.

2. Reasonable close planting. Corydalis saxicola is 55-60 cm tall, with a crown of 40-45 cm. Each plant has 12-14 branches. To allow the plants to receive light reasonably, for field cultivation, ridges are made with a bed length of 18-20 m, a bed width of 1.3-1.4 m, a ditch width of 30 cm and a ditch depth of 20 cm, with 4 rows planted per bed, a plant spacing of 40 cm and 3500-3600 plants per mu. Because Corydalis saxicola seeds are tiny and have weak seedling emergence force, direct seeding in holes has a low emergence rate. To increase the survival rate, it is advisable before planting to use nutritional cups (6 cm x 6 cm) to raise seedlings 50-55 days in advance, and after 6-7 full leaves have grown, transplant them with soil, while pouring 0.5 kg of settling water on each plant.

3. Heavy application of base fertilizer and topdressing. Apply 2500 kg of decomposed cattle pen manure or 4000 kg of farmyard manure per mu as base fertilizer; apply 35-40 kg of potassium sulfate compound fertilizer per mu as topdressing, and when the medicinal seedlings grow to 11 full leaves, apply it deeply in opened holes together with intertillage and weeding.

4. Grain-medicine rotation. When cultivating in paddy fields in high-cold mountainous areas, it can be rotated with middle-season rice; when cultivating on mountain land, it can be rotated with corn. According to trials in Donglan County, Guangxi from 2001 to 2002, under "rice-medicine" rotation, middle-season rice can be sown in mid-May, thrown and transplanted in early June, and mature and harvested in early October. Corydalis saxicola is sown and raised as seedlings in mid-August, transplanted with soil in mid-October, and harvested in early April of the following year. Under "corn-medicine" rotation, corn is sown in late March and harvested in early August. Corydalis saxicola is sown and raised as seedlings in mid-June, transplanted in mid-August, and harvested in mid-March of the following year.

5. Build a shed for shading. For field cultivation, a shed should be built for shading to meet its demand for weak light and temperature conditions. Requirements for the grass shed: roof height 1.8 m, side shed height 1.5 m, shed width 4 m, and shed length determined by the terrain. Cover the shed roof with 1 layer of thin grass or straw, with a light transmittance of 70% being best. Enclose the surroundings of the shed with bamboo stakes and miscanthus stems to prevent damage from livestock and poultry.

6. Medicine garden management. In the early growth stage there is more rain, which easily leads to weeds, so the garden should be cleared and weeded in time; in the late growth stage there is drought and little rain, so attention should be paid to drought resistance and protecting the seedlings. The main diseases are root rot and powdery mildew, and their control should start from the seedling stage. Before the 8-leaf stage, prevention and control should focus on root rot, and when the disease occurs, 700-800 times root rot spirit solution can be used to irrigate the roots. After the 10-leaf stage, prevention and control should focus on powdery mildew, and when the disease occurs, 500-600 times triadimefon solution can be used for whole-plant spraying.

7. Timely harvesting. When Corydalis saxicola grows to the early flowering and budding stage, the yield is relatively high at this time, so it should be harvested on a sunny day. When harvesting, the whole plant can be dug out with a hoe, washed free of soil and debris, air-dried, packaged and sold.