Detailed Explanation of Aconite Cultivation Techniques and Management Key Points

AconiteAlso known as Wutou or Chuanwu, commonly called Wuyiao, it is the processed daughter root of the perennial herbaceous plant Aconitum carmichaelii of the Ranunculaceae family. The lateral roots growing attached to the main root are called aconite (fuzi); the large ones are selected and processed into various sliced preparations and salt-preserved aconite for medicinal use, while the smaller ones are sun-dried and called Chuanwu. After processing, they can be used as medicine. The dried main root is called Caowu, which besides medicinal use can also serve as a starter material for brewing yellow rice wine. Aconite is pungent in flavor, hot and toxic in nature, with functions of strengthening the heart, warming yang, and dispelling cold-dampness. It mainly treats yang collapse with spontaneous cold sweats, reversal cold of the limbs, and a faint pulse on the verge of expiry; kidney yang deficiency with declining vital gate fire, aversion to cold and cold limbs, soreness of the loins and weakness of the legs, impotence and frequent urination; and excess cold-dampness with generalized joint pain. The raw product is highly toxic and must not be taken internally without processing and preparation. It is mainly produced in Sichuan and Shaanxi; Yunnan, Gansu, Hubei and other provinces have also succeeded in introducing its cultivation in recent years.

Plant Characteristics

Aconite belongs to the Ranunculaceae family of perennial herbaceous plants. The tuberous root is obovate; the stem is upright, 60-150 cm tall, with dark brown outer bark; the leaves are alternate, petiolate, usually three-parted or palmately divided, with serrated margins. The raceme is narrow and elongated; from July to September, blue-purple flowers bloom at the top, with 5 petal-like sepals, the upper sepal broad and tall helmet-shaped. The fruit is 13-16 cm long and contains tiny seeds.

I. Growth Habits

Aconite has strong adaptability. Although it is not strict about climatic conditions, it prefers to grow in cool environmental conditions, fears high temperatures, and has a certain degree of cold tolerance. Aconite requires sufficient light and should be cultivated on sunny plots; with ample sunlight, photosynthesis is vigorous, diseases are fewer, and yields are high. However, in the late growth stage, high temperature and strong light prevent normal growth and may even cause wilting and death. It can be cultivated in plains or mountainous areas with annual rainfall of 800-1400 mm, an average annual temperature of 13.7-16.3°C, and sunshine hours of 900-1500 hours.

II. Site Selection and Land Preparation

Aconite has relatively strict soil requirements. It is suitable for cultivation in sandy loam with deep soil layers, fertility, loose texture, and convenient drainage and irrigation. Clay soil, low-lying waterlogged land, and coarse sandy soil with poor water and fertilizer retention are not suitable for planting. Continuous cropping should be avoided; generally, plots where aconite has not been planted for more than three years should be selected, or plots whose previous crop was rice, wheat, corn, sugarcane, or other grass-family crops. After the previous crop is harvested, plow and harrow 1-3 times to make the soil fully fine and level, then use a rope to mark beds in the field at a bed width of 90 cm and a furrow of 30 cm, and apply 5000 kg of decomposed, sieved barnyard manure on the cultivation bed surface for later use.

III. Planting

The best cultivation period is October to November each year, and planting should be completed 6-7 days before the Winter Solstice. Planting too late (after the Winter Solstice) is unfavorable for the growth and development of fibrous roots in the current year; as temperatures rise the following year, sprouts often form first and roots develop afterward, resulting in thin seedlings and slender stems, poor stress resistance and disease resistance, and affecting yield improvement.

For cultivation, use a seeding rake to press holes into the prepared bed surface and plant. The plant spacing is 15×18 cm. Place one seed tuber per hole with the bud pointing upward, and press the soil firm. After a bed is planted, move the soil from between the beds created by the rope marking onto the bed surface to cover the seed tubers, naturally forming furrows between the beds. Cover the bed surface with 6-9 cm of soil; it should not be buried too deep, so as not to affect aconite emergence. After covering with soil, the bed surface is shaped like an arched back. Plant four rows per bed, with an average seeding rate of 100-125 kg per mu. To facilitate intercropping and relay cropping, leave a 15-20 cm empty space on the sunny side of the bed at planting time as the area for the relay crop, and plant aconite on the other side of the relay crop.

IV. Rational Relay Intercropping

1. Yield-Increasing Principle

After years of experimental observation, aconite has different requirements for light intensity during its growth and development period. From emergence to the vigorous growth stage, it requires relatively high light intensity, while entering the late reproductive stage, its need for light intensity gradually weakens. Light intensity must be adjusted in a timely manner to meet the light requirements of the growth period. Timely relay intercropping of short and tall crops on the sunny side of the bed is one of the important technical measures to reduce disease, increase the effective growth period, and achieve high yields. In spring, vegetables are relay intercropped; in summer, grain crops are relay intercropped. In the winter of the first year, spinach is broadcast on the aconite bed surface, and green lettuce is relay intercropped at the bed edge. Before aconite emerges, the spinach is fully harvested. While aconite is still at the seedling stage, the green lettuce has already matured and been harvested, and then corn is dibbled. April to June is the vigorous growth period of aconite, while the relay-intercropped corn is still at the seedling stage. After mid-June, aconite enters the late growth stage; high temperature and excessively strong light instead affect the normal growth and development of aconite, and high temperature and drought can induce the occurrence of southern blight. At this time, the relay-intercropped corn has entered its vigorous growth stage and needs strong light. The tall stems and leaves of corn naturally form a green barrier in the aconite field, improving the field microclimate environment, shading and cooling aconite, and lowering the soil temperature in the aconite root zone. The luxuriant branches and leaves of corn block the frequent summer rainstorms, while the root zone absorbs a large amount of excess water, avoiding the conditions for high temperature and high humidity that cause southern blight infection. This promotes the rapid growth of aconite tubers in a favorable environment, avoids physiological diseases caused by high temperature, and lays the foundation for yield formation.

Intercropping and relay cropping aconite with vegetables and grain forms in the field a pattern of vigorous green lettuce in spring, vigorous aconite in summer, and vigorous corn in autumn, increasing the photosynthetic utilization rate per unit area, making medicine, vegetables, and grain complement each other. The three-material relay intercropping achieves a common harvest and satisfies the biological characteristics of aconite and the intercrops at their respective growth and development stages, effectively preventing and controlling southern blight and improving yield and benefit per unit area.

2. Relay Intercropping Time and Method

After aconite is planted, spinach is dibbled on the bed surface in the winter of the same year, and one row of green lettuce is relay intercropped at the bed edge (plant spacing 40 cm). By the end of February to early March of the following year, after the spinach is fully harvested, aconite has not yet emerged. After the green lettuce is harvested in mid-April, corn is promptly relay intercropped, with a plant spacing of 45-50 cm and 2 seedlings retained per hole. Use a knife to open holes along the bed edge and sow directionally (the broad side of the corn seed parallel to the bed direction) so that corn leaves extend toward the bed surface, which neither affects field ventilation nor better shades the aconite plants. After aconite is harvested in mid-July, Chinese cabbage can be sown on the bed surface; after the Chinese cabbage is harvested, rapeseed can be planted or wheat can be sown in autumn.

V. Field Management

Root trimming: Use a small hand shovel to cut open the soil around the aconite roots and remove the small aconite tubers growing from the main root and the base of the underground stem. The first root trimming is carried out in early to mid-April; the second root trimming is carried out in mid-May. Select and retain 2-4 aconite tubers growing on the mother root and remove the rest. By trimming roots to remove the small and retain the large, nutrients are concentrated for the growth of the retained large aconite tubers, improving the rate of high-quality products during processing into sliced preparations and increasing yield and value. Note that when trimming roots, cut open the soil from one side of the root, just enough to see the small aconite tubers growing on the mother root, and try not to shake the plant or damage the fibrous root system. After trimming one plant, cut open the soil around the next plant and move it to cover the root of the previous plant, proceeding in order. After finishing a bed, clean the drainage ditch and bank the soil onto the bed so that the bed still maintains an arched-back shape.