Detailed Guide to Sophora japonica Flower Bud Cultivation: Planting Methods and Management Essentials
Sophora japonica flower bud is the dried flower bud of the legume plant Sophora japonica L. (Sophora japonica), and has the functions of cooling blood and stopping bleeding, clearing heat and reducing fire. Its dried mature fruit is called Sophora fruit, which has the functions of moistening the intestines and relieving constipation, stopping bleeding and cooling blood.
It is mainly produced in Liaoning, Hebei, Henan, Shandong, Anhui and Jiangsu provinces, and is commonly cultivated throughout China, both north and south.
(1) Morphological characteristics: A deciduous tree, up to 25 m tall. Pinnately compound leaves alternate, with 9 to 15 leaflets, ovate to ovate-lanceolate, apex pointed or acuminate, base broadly cuneate, grayish-white on the underside, sparsely covered with short downy hairs. Panicle terminal, calyx campanulate, corolla milky white. Pod fleshy, constricted between seeds like a string of beads, 2.5-6 cm long, indehiscent, seeds 1-6, kidney-shaped. Flowering period July-September, fruiting period September-October.
(2) Growth habits: Sophora japonica mostly grows in temperate zones and prefers dry and cool climatic conditions. It has the characteristics of light preference, fertilizer preference, cold resistance, wind resistance and pollution resistance. It is not very demanding on soil, but neutral sandy loam that is moist, fertile and well-drained is best. Seeds generally germinate about 1 week after sowing following germination promotion, and the germination rate is 40% after 5 months of storage. In the north, Sophora japonica buds swell in late March, buds open in mid-April, leaves unfold in late April, growth peaks in mid-May, buds appear in June-July, full bloom occurs in July-August, fruit sets in August-September, fruit ripens in September-October, leaves fall in October and overwintering buds form, entering dormancy; the fruit does not fall through winter, and during maturation the pods break off in segments.
(3) Cultivation techniques
1. Site selection and land preparation: Choose sunny, fertile, loose and well-drained loam. Deep plough 60 cm, level and harrow fine, make beds 70 cm wide, and apply sufficient base fertilizer; use 500 kg of decomposed organic fertilizer per mu or 5 kg of urea, and spread 3000-4000 kg of barnyard manure on the bed surface.
2. Propagation methods: Seed propagation can be used, and root suckers can also be used for division propagation.
(1) Seed treatment: Select mature, plump seeds and first soak them in warm water at 70-80°C for 24 hours. After removing them, mix with 2-3 times their volume of fine sand, stir well, pile indoors, and during germination promotion turn them frequently to regulate the upper and lower temperatures so that germination is uniform; this generally takes 7-10 days, and sowing can be done when 25%-30% of the seeds have cracked.
(2) Raising seedlings: Sow in rows or in holes in spring and autumn. For row sowing, use a sowing width of 10-15 cm, cover with 2-3 cm of soil, and press down after sowing, using 10-15 kg of seed per mu; for hole sowing, sow at a hole spacing of 10-15 cm, using 4-5 kg of seed per mu.
(3) Temporary planting and transplanting: In the north, after leaf fall in late autumn and before the soil freezes, lift the seedlings and heel them in for overwintering; dig a heel-in trench 1-1.2 m wide and 60-70 cm deep, then transplant the following spring at a row spacing of 60 cm x 40 cm, and water after planting. For root sucker propagation, dig up sucker seedlings from mature trees, open holes at a row spacing of 1.8 m x 1.3 m, with 1 plant per hole; generally it takes 4-5 years to become a mature plant.
3. Field management
(1) Seedling field management: After the seedlings emerge completely, thin them 2-3 times; in the sowing year, final thinning should be at 10-15 cm. In May-June, apply an appropriate amount of ammonium sulfate or diluted human manure and urine as topdressing; in July-August, pay attention to weeding and loosening the soil. Use 0.75 kg of 25% nitrofen per mu of seedling nursery; when applying, mix an appropriate amount of moist fine soil into the herbicide, then broadcast it around the seedlings. The use of chemical herbicides gives good results and saves labor.
(2) Afforestation and maintenance: Sophora japonica is mostly used as a greening tree species for the "four sides"; in various parts of North China it is planted for street trees, courtyard trees and environmental protection forest belts. During the period when the crown is closed, dead branches and dry forks should be pruned in time, and protection and tending should be carried out to beautify the tree shape.
4. Pest and disease control
(1) Canker disease: Occurs during the seedling stage or after transplanting when drought occurs, damaging branches and trunks. Control methods:
① Strengthen management, apply sufficient water and fertilizer, and enhance disease resistance;
② Mix lime : sulfur : salt : water at 5 : 1.5 : 2.36, and apply it to the trunk;
③ For severely diseased seedlings, cut back the trunk in time and regrow the trunk.
(2) Sophora geometrid: Damages leaves, mostly occurring during the period of luxuriant foliage. Control method: Spray with 1000-fold deltamethrin solution or 1000-2000-fold 50% phoxim emulsion.
(3) Aphids: Generally occur in late spring and early summer, damaging tender shoots, tender leaves and flower buds, with the peak in July-August. Control method: Spray with 3000-5000-fold 2.5% deltamethrin emulsion or 800-fold 40% omethoate solution.
(4) Harvesting and processing
Harvest in summer when flower buds form, dry promptly, and remove branches, stems and impurities to obtain medicinal Sophora japonica flower bud.
After processing and drying, Sophora japonica flower bud is ovate or elliptical, 2-6 mm long and about 2 mm in diameter. In rainy weather, it can be dried in an oven or on a heated kang, with the drying temperature at about 40°C.
In autumn, when the fruit matures, harvest it, remove impurities, and process and dry it to obtain Sophora fruit.