Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Corydalis bungeana

Corydalis bungeana, also known as Zihua Didin or Didincao. The dried whole plant is used as medicine. It has the effect of clearing heat and detoxifying, and is mainly used to treat carbuncles, boils, wind-heat common cold, bronchitis, hepatitis, enteritis and other conditions. The main producing areas are Anhui, Henan, Hebei, Shandong, Jiangsu and other provinces.

Morphological characteristics: It is an annual herb of the Papaveraceae family. The root is slender and long, with lateral roots, and the root is brown. The stem is weak, with many branches, 15-40 cm tall, smooth and hairless, often with 4-5 ridges. Basal leaves and stem leaves are alternate, with long petioles, 2-5 cm long; the leaf blade outline is ovate, 2-4 times pinnately parted, with 2-3 pairs of lobes, with slender petioles or almost sessile, and the small lobes are lanceolate or long elliptic, with obtuse apex. The base is decurrent. Racemes are axillary, the inflorescence is 1-6 cm long, with leaf-like bracts. Flowers are light purple, about 2 cm long, borne horizontally on small pedicels, the small pedicels are about 2 mm long, sepals are small, in 2 whorls, scale-like; petals are 4, the outer 2 are large, the upper 1 has a tail extending into a cylindrical spur, the spur is about 0.5 cm long, the front end is slightly wavy, the lower petal has a shallow bundle shape, the apex is slightly concave, the inner 2 petals are smaller, dark purple at the apex, slightly united at the apex, stamens are 6. The filaments are united into two flat bundles, and the filament base of the stamens opposite the spurred petal has nectar glands inserted into the spur; each bundle has 3 pale yellow anthers; pistil is 1, style is slender and short; stigma is laterally flattened; ovary is superior, flat columnar, about 5 mm long, 1-loculed, parietal placenta, with many embryos in each locule. Capsule is long elliptic, green, 7-20 mm long, 2-6 mm wide, style and stigma persistent, dehiscing by 2 valves. Seeds are numerous, round-kidney-shaped, black, shiny. Flowering period is May.

I. Growth habits: Didin has strong adaptability and prefers a warm and slightly cool climate. It is cold-resistant and afraid of drought. It has no strict requirements for soil, and can be planted in clay, loam and sandy loam. It is afraid of waterlogging, and is not easy to plant in low-lying land.

II. Land preparation and fertilization: Choose a field with high terrain and good drainage, and cultivate carefully. Combined with land preparation, apply sufficient base fertilizer: apply 3000 kg of farmyard manure, 20 kg of urea, and 50 kg of phosphorus and potassium fertilizer per mu. Then make beds and wait for sowing.

III. Sowing: Corydalis bungeana is propagated by seeds. The sowing period is around White Dew. When sowing, evenly scatter the seeds onto the prepared bed surface, then rake level so that the soil covers the seeds. Water to preserve moisture and promote seedling emergence. The sowing rate is 3 kg per mu.

IV. Field management: After Corydalis bungeana seedlings are fully emerged, pay attention to intertillage and weeding. Water frequently in dry weather, and drain promptly in rainy weather. Apply topdressing once before and after row closure: apply 10 kg of urea and 5 kg of potassium dihydrogen phosphate per mu.

V. Pest and disease control: The main disease of Corydalis bungeana is root rot, which can be controlled with 1:1:120 Bordeaux mixture before onset. In the early stage of the disease, use carbendazim for control. For underground pests, phoxim can be used with poisoned bait for trapping and killing.

VI. Harvesting and processing: Didin is generally harvested in May-June, when it is half in flower and half in seed. When harvesting, dig out Didin together with the roots and remove the soil completely. Sun-dry it and it can be sold as medicine. The yield per mu is 150 kg.