Planting technique of Yuanhu

Rhizoma Corydalis, also known as Corydalis, is a perennial herb of the genus Corydalis in the poppy family. It is used in medicine with dry tubers, which has the effect of promoting blood circulation and dispersing blood stasis, promoting qi and relieving pain. "Lei Gong gun burning theory" contains "heartache to death, looking for Yuanhu quickly". The Compendium of Materia Medica records: "Xuanhusuo can exercise qi stagnation in blood and blood stagnation in qi, so it specializes in treating all kinds of pain up and down the body."

Botanical characteristics of Rhizoma Corydalis

Rhizoma Corydalis is a perennial herb with a stem height of 10 to 20 cm. Tuber globose, inner yellow. Aboveground stems slender and slightly fleshy, leaves 3-4, leaves 2-Ternate-cleft, ultimate segments lanceolate or narrowly ovate. Racemes, bracts ovate, sepals very small, early deciduous; petals purplish red, 4, arranged in two whorls, outer whorls slightly larger, outermost one extending at the base of the growing moment; inner whorls two narrow, healing. Six stamens, two bodies. The ovary is superior, composed of two carpels and one chamber. Fruit a capsule, flat columnar. The flowering period is from March to April and the fruit period is from April to May.

Biological characteristics of Rhizoma Corydalis

Rhizoma Corydalis grows in mountainous, sparse woodland or grass on the edge of the forest, likes a warm and humid climate and is afraid of strong light. Afraid of drought, can withstand cold. The growing season is short and the demand for fertilizer is high. The strong wind is bad for its growth.

The root system of Rhizoma Corydalis is shallow, which is mainly distributed in the surface soil layer of 1 inch to 3 inches. Tubers generally have 1-2 buds, 3-4 in most, and 1 in less. The optimum temperature for sprouting is 18-21 ℃. In Hanzhong area, seedlings generally begin to emerge after the Beginning of Spring (early February), and end around the Rain and Water Festival (end of February). Seedlings emerge from late January to early February in most parts of the country.

Before the emergence of Yuanhu, the underground stem had already begun to elongate and grew slightly upward along the horizontal direction. The first stem node was formed in late November, and the underground stem was completed by early February. Each species of tuber could grow 2-4 underground stems, each with 2-5 stem nodes.

It takes 100-120 days for the underground stem growth stage from sowing to emergence, followed by the tuber formation stage. There are two parts in the formation of Yuanhu tuber. First, it is formed by the expansion of the nodes of the underground stem, which is used to be called "Ziyuanhu". Usually under the condition of fine planting and adequate fertilization, a tuber of Rhizoma Corydalis can be expanded from the nodes of its underground stem to form more than 10 Yuanhu. However, if there is not enough fertilizer, extensive planting, planting a Yuanhu tuber, can only grow 5-8 Yuanhu. Second, it is developed from the tissue of the seed stem, which is used to be called "Mother Yuanhu". The female Yuanhu began to form from early February to late February. On the other hand, "Ziyuanhu" begins to form from the expansion of the growth node of the stem node, which takes about 50 days, that is, the expansion period of the stem node from mid-March to late April. The peak period of new tuber growth is from late March to mid-April. During this period, the growth of Yuanhu has a direct impact on the harvest yield.

Rhizoma Corydalis is a typical solar plant. The growth is faster and the life span is shorter (the growth cycle is short). From sowing to harvest is only about 210 days, the real growth period is only about 100 days. Therefore, applying sufficient base fertilizer, paying close attention to topdressing, and ensuring the adequate supply of water and fertilizer during the growing period play a decisive role in increasing production. In Dongyang County, Zhejiang Province, medicine farmers believe that the best weather during the peak growth period of Yuanhu in early spring is "three sunny and three rains" (that is, once a week). Therefore, in case of drought in early spring (especially from March to April), irrigation must be given in time (once a week), which is the key to achieving high yield.

According to the above, combined with the study of national Yuanhu production experience, the living habits of Yuanhu can be simply summarized into three sentences: "three joys" (like sunshine, warmth and moisture), "three fears" (fear of stagnant water, fear of drought, fear of continuous cropping), "five no species" (① clayey yellow soil and alkaline soil can not be planted; ② low-lying paddy fields cannot be planted; ③ continuous cropping fields should not be planted; ④ is not suitable for planting without irrigation and drainage conditions. The stem of ⑤ seed cannot be sown without disinfection. Careful selection of suitable growth environment and strict control of the "five passes" are very important to improve the per unit yield of Yuanhu.

Planting techniques of Rhizoma Corydalis

The cultivation techniques of Rhizoma Corydalis can be summarized into four sentences: "shallow, thin, warm and wet". The so-called shallow point, that is, the depth of planting (covering soil) should be 2 inches; sparse, that is, the sowing density should be 2.5 inches square or 2 × 3 inches between rows and plants; warmer, that is, to keep warm for the winter; and a little wet, that is, the side of the box should be kept moist and not too dry.

1. Sorting out the land for use as compartments

Choose the site for ①. To plant Rhizoma Corydalis, we should choose fertile land (field) with deep soil layer, good irrigation and drainage and high soil organic matter content. Sandy loam is suitable, such as sandy mud, semi-sand and semi-mud field, alluvial soil is the best. Dead yellow mud, white loessial soil and gravel soil are not suitable for planting. The physical and chemical properties of soil should be neutral or slightly acidic, and the pH value is usually about 5.6-7.5.

The root system of Rhizoma Corydalis is mainly distributed in the 1-3 inch topsoil layer. The looser the soil is, the more developed the root system is, which is beneficial to the expansion of stem nodes and the absorption of nutrients. Soil consolidation is not conducive to the growth and expansion of stems and branches, the stem nodes are small and the yield is low. If the soil is alkaline, it is easy to form stiff seedlings, grow slowly, and root whiskers (stem branches) atrophy. The soil quality through sand has poor water and fertility conservation, which is easy to form premature senescence, and the growth is inhibited because the sand absorbs heat too strongly, the temperature difference between day and night changes greatly, and the ground temperature exceeds the environment needed by crops.

② prepares the ground. After planting Rhizoma Corydalis, the first step is fine farming. Three ploughing and three harrowing, finishing the topsoil into loose and fine loam, which is the basis for winning Yuanhu to increase production. If there are many large soil blocks in Yuanhu field, it will not only affect seedling emergence, but also hinder root growth, which will seriously reduce the yield in the coming year. Yuanhu field preparation should be combined with sufficient base fertilizer, because the root of Yuanhu is shallow like fertilizer, and the growing season is short, so applying sufficient bottom fertilizer is the key to increase production. According to the analysis of the results of large area high yield experience, better yield can be obtained by applying rotten pig and cattle manure, cruller fertilizer and phosphate fertilizer per mu. If indiscriminate application of cruller fertilizer or direct contact with unrotten fertilizer will cause burning of seedlings, although the seed stem does not change color, nor rot, the bud will stop growing after 1-2 cm of germination. If too much nitrogen fertilizer is applied, it will cause the stems and leaves to grow, lodge in the case of heavy rain, and create favorable conditions for the parasitic reproduction of downy mildew spores, resulting in mass death after infection, resulting in reduced yield. Therefore, in the application of cruller fertilizer, early fermentation is beneficial to the full absorption of Yuanhu root system.

③ acts as a compartment. Immediately after the consolidation of the plot, it is usually appropriate to use the horizontal box, which is beneficial to drainage and irrigation. at the same time, the box surface is short and easy to flatten, which can improve the land utilization rate. The reasonable use area of one mu of land is about eight points. Generally, the width of the chamber is 4 inches, the width of the trench is 7 inches-1 foot, and the depth of the trench is 5-7 inches. The specific structure is shown in the figure:

2. Planting time and method

① seeding time. Yuanhu propagates with tubers and the growth period is short, which takes up only one season of wheat. The profit is big, the output is high, the effect is quick. The planting time is the high yield period between the Autumn Equinox and Cold Dew (that is, from late September to the first and middle of October), and the producing area has the experience of "planting early and applying fertilizer once". If the growth time of the underground stem is less than 100,120 days before emergence, the yield will be significantly reduced when it is postponed to be planted after Frosts Descent.

② seed selection. To choose the medium-sized seed block uniform, flat round yellow no scars, no insect population of the new-born Ziyuanhu as seed. If the selection is too large, the amount of seed will increase. If the old mother and son Yuanhu is used as seed, the reproductive ability is weak, which will affect the yield. According to the requirements of the selected seeds, there are many buds on the tuber, the seedlings are robust and have strong disease resistance.

③ reasonable close planting. When planting in the box, it is more reasonable to plant with a row spacing of 2 × 3 inches or 2.5 inches. It was proved by field experiment that the incidence rate was proportional to the density of the next species. That is, the higher the density, the faster the infection, the higher the incidence, and the more serious the disease. The comparative test results of the following density of 2 inch, 2.5 inch and 3 inch density were as follows: April 11 examination: 2 inch density infection rate was more than 55%; 2.5 inch density infection rate was 20%. 3 inch density infection rate was 10%. April 25 check: density 2 inch seedling 100% 2.5 inch seedling 70% sheng 3 inch seedling 40%. Early seedling return will affect the yield, and delaying seedling return can increase the yield. The reason for excessive density and infection is that the overdensity of aboveground stems and leaves affects the microclimate of Yuanhu border, poor ventilation and lack of light, which relatively increases the humidity of Yuanhu border, and provides a good parasitic breeding environment for the pathogen of downy mildew. therefore, the disease occurs early and spreads quickly. However, it should not be planted too sparsely, and the yield per unit area will decrease.

④ cover soil. A reasonable depth of soil cover should be maintained after planting. It is appropriate to take 2 inches to 2.5 inches. In some cold places in winter, the depth of soil cover can be increased to 3 inches. Because the root system of Rhizoma Corydalis is shallow, such as thin soil cover, few branches of underground stem, short stem nodes, overlapping tubers and low yield. Covering the soil too deep will affect the emergence of seedlings and can not guarantee the whole seedling.

⑤ planting method and sowing amount per mu. First, pull the rope to step on the box on the whole plot, put the seeds on the side of the box according to 2.5 inches square, and sprinkle a thin layer of old wall soil or rotten fine broken farm fertilizer on the set, with a dosage of 2000-3000 jin per mu, 100 jin of oil cake fertilizer and 100 jin of phosphate fertilizer, and then raise the soil in the box ditch to the wing surface with a hoe, which is the cover soil, which causes the shape of the bow. The sowing rate per mu is generally about 120-140 jin, which varies with the seed size.

Field Management of Yuanhu

① weeding. Yuanhu is closely planted in the box, the root system is very shallow, and grows laterally along the topsoil, so it is not suitable to use weeding to avoid breaking the stem buds or bringing out the seedlings. It is generally advocated to pull grass by hand, but it is more labor-intensive. It takes 15-20 working days to pull grass in one mu of Yuanhu. In order to save labor, Yuanhu producing areas promote the use of iron rakes or bamboo rakes to remove weeds in winter. Specific practice: twist into an iron tooth rake with iron wire, the rake tooth length is 1 inch, install bamboo handle or wood handle, after planting in Yuanhu for a week, rake with iron rake in Yuanhu box every 5-7 days to pick up the grass roots, which can be finished in early December. In this way, weeds will be significantly reduced after seedling emergence in the coming year, and weeds can be removed with three or five more labors. It should be noted that the rake teeth should not be more than 1 inch long and should not be raked too deep to prevent damage to seed stems and stem buds.

② topdressing. The production practice in Zhejiang and Hanzhong areas has proved that "applying sufficient base fertilizer, re-applying wax fertilizer, skillfully applying seedling fertilizer and increasing phosphate fertilizer" is an important factor in increasing yield. The results showed that the application of phosphate fertilizer increased by 100jin per mu, compared with only 300jin of cruller fertilizer, the yield was increased by 11.3%. Fertilization time: ⑴ base fertilizer was applied into the topsoil layer of cultivated Yuanhu before planting; ⑵ wax application: before emergence of Yuanhu from late November to early December, pig and cattle manure and human manure were suitable, in which pig and cattle manure was 3000-4000 jin per mu and human manure was 2000 jin; ⑶ seedling fertilizer: when the seedling height was more than 1 inch in early February for the first time, dilute urine 2000-3000 jin per mu, or urea 5kg 8 jin, watered with water The second time from the first ten days of March to the middle of March, combined with irrigation, urea 8-10 jin per mu, or nitrogen and phosphorus compound fertilizer 10 kg per mu; the third time from late March to mid-April, in case of continuous overcast and rain, apply plant ash 5 kg 10 jin once a week, which not only has fertilizer effect, but also has disease prevention and germicidal effect.

③ irrigation and drainage. From mid-March to late April, it is the peak growth period of Yuanhu, which requires more water. in case of drought and less rain, it is advisable to irrigate once a week, preferably in the early morning or evening. Each irrigation should be slow and rapid retreat, do not drown the box, can not make irrigation stay in the field for too long, let alone overnight. Irrigation should be stopped as the harvest approaches after late April. In addition, in case of winter drought, winter irrigation can be carried out, which is beneficial to the germination and growth of stem buds of Rhizoma Corydalis. However, after heavy rain, the stagnant water in the field should be removed in time.

Pest control of Rhizoma Corydalis

The common diseases of Yuanhu are downy mildew, Sclerotinia sclerotiorum and rust. The distribution area of downy mildew is wide and the harm is more serious.

1. Downy mildew. Bupleurum downy mildew is an infectious disease caused by half-known fungi and algal bacteria. At the initial stage of the disease, the injured leaves produced brown dots (that is, the pathogen spore pile), and then gradually expanded to form irregular brown spots, gradually covering the whole leaf. When the humidity is high, a layer of gray frost (hyphae) is formed on the back of the leaves. When the humidity is suitable, the disease develops rapidly, and the whole field can be infected after three to five days, and the surface of the stems and leaves turn brown, and the color deepens, like fire, so the disease is commonly known as "fire plague". In the end, the diseased leaves rotted and withered, and the plant died quickly. The spores of Yuanhu downy mildew are infected with wind and rain, or overwintered with diseased tissue in the soil, and their life span can be as long as three or four years, so they can not plant continuous cropping land in the coming year to avoid repeated infection.

[prevention and control methods]

Seeds were soaked in ①. 65% Dysen zinc was used to prepare a 350-fold solution. Rinse the selected seeds with clean water, then soak them in the solution for 10 minutes, and then sow the seeds after a little drying.

② chemical control. Select 40% ethyl aluminum (also known as bengshuangling) to prepare 1RV 350 × 500 times (due to the continuous use of ethyl aluminum in old producing areas, the spores of bacteria have produced drug resistance, so the concentration is appropriately increased to 1 250% 300 times; the new producing areas can use a lower concentration of 400-1200 times), or 70% mancozeb 800-1200 times can be sprayed alternately with ethyl aluminum, and the control effect is better. At present, aluminum ethyl phosphate is an ideal agent to control downy mildew of Yuanhu, which can inhibit sporangia germination and zoospore release of asexual reproductive organs of downy mildew, inhibit the growth of Phytophthora hyphae, and kill the released zoospores. After being absorbed by plants, it also has two-way transmission (that is, apexy and geotropism), while other agents such as Dysenzin and topazine are ineffective against algal bacteria. The prevention and control practice in Hanzhong area for many years has also proved this point.

③ plant fungicide. The leaves of Salix mandshurica, Melia azedarach bark and Artemisia annua were 1 kg each, 15 kg cold water was added and soaked for 7 days. It is characterized by safe use of drugs, non-toxic side effects and residual toxicity, which can not only postpone the onset of downy mildew until mid-April, but also postpone returning seedlings and increase yield. Chenggu County Medicinal Materials Company used eight groups of different agents to control downy mildew at the Dongjiaying Yuanhu research site in 1985. the experimental results showed that the yield-increasing effect of plant fungicides was second only to aluminum ethyl phosphate.

2.Sclerotinia sclerotiorum. Sclerotinia sclerotiorum is caused by an ascomycete in fungi. The sclerotia is black on the outside and white on the inside. During germination, several ascomycetes can grow above, and numerous ascosms are arranged in the ascomycetes, each of which contains 8 ascospores. Yuanhu is mainly harmful to the base of stems and leaves near the topsoil, resulting in yellowish-brown or dark brown prismatic spots. When the humidity is high, the stem base is soft rotten, the plants lodge, the branches and leaves come together and die, and the bunches of rotten stems and leaves are turned up by hand. The soil surface is covered with white cotton-like hyphae and irregular black rat feces-like sclerotia of different sizes. As the disease occurs at the base of the stem of Yuanhu is soft rot, so the masses are also known as "chicken nest plague" or "leaf rot". The disease was relatively rare in Hanzhong area in the past, but it occurred a little in some places where it had been planted for a long time in recent years, and it was caused by seed-borne bacteria. Sclerotinia sclerotiorum begins to occur in mid-late March and spreads more in April, especially in early spring with rainy, low-lying terrain, poor drainage, and easy to occur and infection when planting density is too high.

[prevention and control methods]

① can rotate with Gramineae crops (wheat, rice, corn), preferably with flood and drought rotation.

② opened ditches and drained water in time after rain to reduce field humidity and reduce the incidence of disease.

③ found diseased plants, pulled out them in time, and sprinkled lime.

④ was sprayed with 1 jin of copper sulfate and 1 jin of quicklime plus 300 jin of water before emergence, and alternately with carbendazim and Bordeaux solution after emergence and during the critical period, once every 7-10 days.

3. Rust. Rust is a kind of disease caused by basidiomycetes in fungi, which is less harmful to Yuanhu. It occurs when the spring rain is continuous, the air humidity is high, the temperature is low, and the soil is wet, which mainly harms the stems and leaves of Rhizoma Corydalis. In the early stage of the disease, irregular yellow-green dark spots appeared on the leaf surface, and in the later stage, the disease class was obvious, showing orange, and the spot was slightly sunken. Leaf back disease class bulge, and born with orange protruding colloid, that is, its summer spore pile, spore pile broke out a large number of rusty yellow powder (that is, summer spores). In addition to harming Yuanhu, it also harms other crops.

[prevention and control methods]

① agricultural control. After discovering the diseased plants, all the diseased plants were taken out and poured into the pit with raw lime water to suffocate the spores of the pathogenic bacteria and prevent infection.

② chemical control. Starting from the first and middle of March, the water solution of 400-500 times was sprayed with 97% sodium rust, or 200-250 times with 50% dinitrate powder, and the medicine was used alternately every 7-10 days, and the effect was better.

Harvest and processing of Rhizoma Corydalis

1. Harvest. In Hanzhong area, the aboveground stems and leaves of Yuanhu can be harvested when they are withered and yellow in late April. However, if fine tillage and timely field management can postpone the inverted seedling stage, some can be postponed to the beginning of May, and the yield will be relatively increased by about 1020%. Generally, the yield per mu is 600jin (fresh), the yield of high-yield fields can reach 800jin per mu, and the highest yield per mu has reached 1301 jin. Rhizoma Corydalis can grow more than 40, 000 plants per mu, with an average yield of 20 grams per plant, with a yield of 1600 jin per mu, with great potential to increase production.

2. Harvest time. Generally speaking, mining began in early May after the Beginning of Summer's festival. Yuanhu tuber is relatively small, to choose a sunny day, with a small wire rake to dig, or with a small hoe to dig. When you take back Yuanhu, you should spread it out immediately and keep in mind that it can not be stacked in sacks, otherwise it is easy to have a fever and mildew.

3. Seed selection and storage. After harvest, the seeds of Rhizoma Corydalis were first selected, and the medium-sized Bupleurum with a diameter of 1.4-1.6 cm without diseases and insect pests was selected as seeds. The selected seeds should continue to be thinned and dried indoors to distribute moisture. After about 10-15 days, the seed coat can be stored with tidal sand after the seed coat is white and slightly dry. The specific method is: first lay 2-3 inch thick tidal sand indoors, put 4-6 inch thick Yuanhu seed on the sand, and then spread 2-3 inch thick tidal sand on top, stacked layer by layer, the height shall not exceed 2-3 feet. Regular inspection should be carried out after stacking to prevent rodent damage. At the same time, when stacking, put a few bunches of straw in the heap, leaving them as gas eyes to prevent fever. If you find a fever, sprinkle water evenly from the top of the pile with a sprinkler. If it is found that it is too wet and moldy, turn the pile immediately, remove the rotten grains, add the wet sand into the dry sand, and store it until the next seed.

4. Processing. After selecting the seeds, the rest of Yuanhu was screened and divided into two categories, washed the soil and boiled in boiling water. Dayuan Hu boiled for about 3-5 minutes, Xiao Yuanhu for 2-3 minutes, when the knife cut the cross-section without a white heart, fish it out and dry it to become a dried Yuanhu commodity. Generally speaking, three jin of fresh yuanhu can process one jin of dry goods.