What are the growth and development stages of Astragalus membranaceus?

Speaking of Astragalus membranaceus, I think everyone is very familiar with it. It is a relatively common and relatively frequently used traditional Chinese medicine. Traditional Chinese medicine has several thousand years of culture and history in our country, so the effects of traditional Chinese medicine have always been recognized by the people of our country.

How many growth and development stages does Astragalus membranaceus have

From sowing the seeds to the maturation of new seeds, Astragalus membranaceus needs at least more than 2 years, going through 5 growth and development stages, namely the seedling growth period, the withered overwintering period, the greening period, the budding and flowering period, and the fruiting and maturation period.

1. Seedling growth period. The period from the emergence of the cotyledons of Astragalus membranaceus to the formation of flower buds is called the seedling growth period. After the seedlings of Astragalus membranaceus emerge, before 5 small leaves appear, the root system has not yet fully developed, its absorption capacity is poor, and it is relatively shallow in the soil. At this time, it is most afraid of drought, high temperature, strong light and hot wind. After 5 small leaves appear on the young seedlings of Astragalus membranaceus, the absorptive roots underground increase significantly, the root system's ability to supply water and nutrients is stronger, the leaf area expands, photosynthesis is enhanced, and the growth rate of the seedlings speeds up. Usually, Astragalus membranaceus sown in the same year cannot bloom or bear fruit, and all are in the seedling growth period.

2. Withered overwintering period. The period from the withering of the aboveground part to the greening of the plant in the second year is called the withered overwintering period. Generally, in late September the leaves begin to turn yellow, the aboveground part withers, and the aboveground overwintering buds form. This period needs to go through 180~190d0

3. Greening period. Refers to the period when the terminal buds of overwintering Astragalus membranaceus sprout and grow out of the soil surface. In spring, when the ground temperature reaches 5°C-10°C, Astragalus membranaceus begins to green up. First the clustered terminal buds grow out, then stems, branches and leaves differentiate to form new plants. In the early stage of greening, the growth rate is generally relatively slow, mainly because it is greatly affected by soil temperature and moisture.

4. Budding and flowering period. Refers to the period from the formation of flower buds in the leaf axils to before the appearance of fruit. Plants that have grown for more than 2 years generally produce flower buds in June, which gradually swell, the pedicels produce flowers, and the flower buds gradually form. In early July the flower buds open, and the flowering period is 20~25d.    

5. Fruiting and maturation period. Refers to the period from the beginning of pollination after flowering of Astragalus membranaceus to the maturation of the fruit. Generally from mid-August to mid-September. If this period encounters high temperature and drought, this period will be advanced, and the seed coat will form impermeability, the hard seed rate will increase, and the seed coat quality will decrease.

Field management of Astragalus membranaceus  

When Astragalus membranaceus is 6-8 cm tall, thin the seedlings, as long as they are not crowded. After final thinning, water and topdress fertilizer, using 10-15 kg of urea per mu. During the seedling stage, pay attention to intertillage and weeding. In the rainy season, when humidity is too high, pay attention to drainage.  

1. Thinning and replanting: When the seedlings are 5-7 cm tall, carry out the first thinning. After 2-3 thinnings, leave 1 strong seedling every 8-10 cm. If there are missing plants, replant with small seedlings with soil, or reseed with sprouted seeds to fill the gaps.  

2. Topdressing: In the first and second years of growth, apply fertilizer once each year in combination with intertillage and weeding. Apply 1000 kg of decomposed human and livestock manure water per mu or 7-8 kg of three-element compound fertilizer (N, P, K each 15%). After the plants wither in the first winter, apply 2000 kg of barnyard manure plus 10 kg of three-element compound fertilizer (N, P, K each 15%) and 150 kg of cake fertilizer per mu. Mix thoroughly and apply in furrows between rows, then earth up to prevent freezing.  

3. Topping: Topping is done to control plant height growth and reduce nutrient consumption. Topping before the end of July can increase yield.  

4. Intertillage and weeding: The seedlings of Astragalus membranaceus grow slowly, and if weeding is neglected, it is easy to cause weed infestation. Therefore, when the seedlings are about 5 cm tall, carry out intertillage and weeding in time in combination with thinning. The second time is when the seedlings are 8-9 cm tall, and the third time is after final thinning, carrying out intertillage and weeding once each. After the second year, weed once each in May, June and September.

Pest and disease control of Astragalus membranaceus  

1. Powdery mildew: The peak incidence of powdery mildew is during the high-temperature and humid period from July to August. It damages leaves and pods. White downy mold spots appear on both sides of the affected leaves and on the surface of the pods, and many small black spots appear later, causing severe yield reduction. In the early stage of the disease, spray 2-3 times with 25% triadimefon 1500-fold solution or 1:1:120 Bordeaux mixture, and the effect is relatively good.  

2. Aphids: Often occur in July-August, damaging tender shoots, and are especially serious in hot and dry years. They can be controlled by spraying 40% dimethoate 1000-1500-fold or 50% pirimicarb 2000-3000-fold.  

3. Pod borer: Adult pod borers lay eggs on the tender pods or flower buds of Astragalus membranaceus. After hatching, the larvae bore into the pods and eat the seeds. The mature larvae drill out of the pods, enter the soil and spin cocoons to overwinter. During the flowering period, spray dichlorvos or decis according to the dosage once every 7 days, continuously spraying 3-4 times, until the seeds mature.  

4. Violet root rot of Astragalus membranaceus: Violet root rot of Astragalus membranaceus is commonly known as “red root disease”, because after onset the roots turn reddish brown. It first affects the fibrous roots, then gradually spreads to the main root. The root rots from the cortex inward, and finally the entire root rots completely. In addition to removing diseased residues, crop rotation, and drainage in the rainy season, 1.5-2.0 kg of 70% dexon per mu can be used for soil disinfection in combination with land preparation, or in the early stage of the disease, carbendazim, thiophanate-methyl, tebuconazole, etc. can be used to drench the roots.

Site selection and deep plowing for Astragalus membranaceus  

Astragalus membranaceus is a deep-rooted plant. The planting site should be selected as neutral or slightly acidic sandy soil with deep soil layers, loose and fertile texture, good drainage, high and dry terrain, and sunny exposure. Flat land, hills, and mountain slopes can all be used for planting. Clay soil with a high groundwater table, high soil moisture, tight and sticky texture, and low-lying waterlogged areas, or barren gravelly soil, are all unsuitable for planting Astragalus membranaceus. After selecting the plot, deep plow to improve the soil. After the autumn crops are harvested, deep plow the soil more than 30 cm to break the plow pan; before plowing, remove weeds, stones and residues from the field.  

According to many years of planting evidence from the base of the Heze City Runkang Traditional Chinese Medicinal Materials Research Institute in Shandong, deep plowing can thicken the active soil layer, mature the soil, enhance the soil's capacity to store water and preserve moisture, improve soil aeration, promote microbial activity, accelerate the decomposition of organic nutrients, increase soil fertility, benefit root growth, and reduce the formation of lateral roots and “chicken-claw astragalus”. It is an effective measure for obtaining high-quality and high-yield Astragalus membranaceus.

The cultivation of traditional Chinese medicine is relatively common in our country. Many years ago, quite a few people made a living by growing traditional Chinese medicine. Mastering some growth habits of traditional Chinese medicine and some basic cultivation techniques is very helpful for growing traditional Chinese medicine.