Field management techniques for the perennial herb Codonopsis pilosula in dryland

Codonopsis pilosulaIt is a perennial herb of the genus Codonopsis in the family Campanulaceae. Because it originated in Shangdang, Shanxi, and its root resembles ginseng, it is called Codonopsis pilosula. Its root is used medicinally and has the effects of tonifying the middle and boosting qi, nourishing blood and supplementing the lungs, promoting fluid production and relieving thirst, and strengthening the spleen and stomach. It mainly treats symptoms such as shortness of breath and weakness, weak spleen and stomach, poor appetite, edema with deficiency and coughing and wheezing, and qi deficiency with rectal prolapse. Codonopsis pilosula includes several types: West Codonopsis (produced in Shaanxi, Gansu, Shanxi and other provinces), East Codonopsis (produced in the northeastern provinces), and Lu Codonopsis (produced in Shanxi, Henan and other provinces), with Taidang among the West Codonopsis being the best in quality.

Codonopsis pilosula prefers a cool climate. Seedlings prefer shade and moisture, while larger seedlings and mature plants prefer a dry, sunny environment. It has strong adaptability and can tolerate high cold, while hot and stuffy summer weather is unfavorable to its growth. Because its roots are deep, the cultivation site is best with deep soil layers, loose and fertile soil texture, and loam rich in humus; clay soil and saline-alkali land are not suitable for cultivation.

1. Field management

Dryland Codonopsis pilosula is generally sown in mid-September to mid-October when there is moisture in the soil. When the soil temperature is around 15°C, seedlings can emerge in 5-7 days. (Generally, about 2 kg of seed is used per mu of Codonopsis pilosula.) The field management work after seedling emergence is as follows:

(1) Intertillage and weeding. When the seedlings grow 2 true leaves, shallow hoeing is done to loosen the soil and remove weeds, and thinning is carried out together with weeding, with a plant spacing of 5 cm.

(2) Topdressing. In spring each year, 25-30 kg of compound fertilizer per mu can be applied as topdressing; before row closure or trellising, 1000-1500 kg of human and livestock manure water is applied; in autumn, 1000-1500 kg of compost or 50 kg of superphosphate and 20 kg of diammonium are applied.

(3) Trellising. When the Codonopsis seedlings are 30 cm tall, supports can be set up so the vines grow along the trellis. This not only facilitates ventilation and light penetration and enhances photosynthesis, but also prevents diseases in the field caused by excessive temperature. This is a major yield-increasing measure in Codonopsis pilosula cultivation.

(4) Pest and disease control. 1) Root rot of Codonopsis pilosula generally begins to occur in May-June. In the early stage of the disease, diseased plants should be pulled out promptly, and roots should be drenched with a 2000-fold solution of 50% thiophanate-methyl, once every 7-10 days for 2-3 consecutive times; 2) July-August is the occurrence period of Codonopsis rust, which can be controlled by spraying a 1000-1500-fold solution of 25% triadimefon; 3) To control red spider mites, a 3000-fold solution of 1.8% abamectin can be sprayed; 4) To control aphids, imidacloprid or pyrethroid insecticides can be used; 5) For underground pests such as cutworms and grubs, poisoned bait made from trichlorfon and wheat bran can be used for trapping and killing.

2. Harvesting and processing

1. Harvesting. Codonopsis pilosula can be dug up 3 years after sowing. In autumn, after the aboveground stems and leaves turn yellow and wither, choose a sunny day and carefully dig out the roots, avoiding injury and breakage; otherwise, the sap will flow out and form black scars that affect quality.

2. Processing. Wash the dug-out Codonopsis roots clean and grade them, spread them on a drying mat in the sun for 2-3 days. When the roots become soft, tie them into small bundles, hold the root head with one hand, smooth downward with the other hand, and rub several times. The next day, dry them again in the sun, bring them back in the evening and rub again, repeating many times. Then place them on a wooden board and press and rub repeatedly, and continue drying them in the sun to obtain the commercial product.