Cultivation Techniques and Benefit Analysis of Polygala
Polygala can be planted from spring until around White Dew. It is harvested after 2-3 years. The seeding rate is 2.5-3 kg per mu. The price of commercial polygala ranges from 30-90 yuan per kg, with price determined by quality. The yield per mu is 250-300 kg, with an average annual income of 3,000-4,000 yuan per mu. Polygala is best planted in furrows, with a furrow depth of 1 cm and a row spacing of 21-23 cm, without thinning.
The polygala species used for medicinal purposes are thin-leaf polygala (Polygala tenuifolia) and broad-leaf polygala (Polygala sibirica). Polygala usually refers to thin-leaf polygala, a perennial herb of the family Polygalaceae. Its root is used as medicine. It is bitter in taste and warm in nature. It has the effects of calming the mind and boosting intelligence, dispelling illness and relieving depression. It mainly treats palpitations, neurasthenia, nocturnal emissions, cough with excessive phlegm, bronchitis, and painful boils and sores.
Growth Habits
It grows wild on sunny hillsides, under forests, in grasslands or in rock crevices. It prefers cool climates, avoids high temperatures and is drought-tolerant. Sunny sites with good drainage and deep, fertile soil are best. Continuous cropping should be avoided. It is mainly produced in Shanxi, Shaanxi, Hebei, Henan, Northeast China, North China, Northwest China, East China and Central China, and can be cultivated in all these areas.
Market and Benefit Analysis
Polygala is a bulk medicinal material with large demand. Due to extensive harvesting, wild resources are gradually declining. Commercial polygala is increasingly scarce, especially the medium- and high-grade polygala tubes for export, which are now extremely rare. Polygala flesh was only 7-8 yuan/kg in 1985, and has now reached 30-58 yuan/kg. Export-standard polygala tubes are priced as high as over 95 yuan, and there is a trend of continued increase. In the second year, polygala can produce 7-10 kg of seeds per mu. In the third year, seed production can reach 10-15 kg per mu. It produces 250-300 kg of medicinal material. The total output over three years exceeds 10,000 yuan per mu, with an average annual output of over 3,000 yuan per mu. Artificial cultivation of polygala is already mature, and there are no technical problems. Polygala has long been a best-selling medicinal material for export. Wild polygala resources are depleted, making it a good variety for developing medicinal herb cultivation. Plant characteristics: perennial herb, plant height 30-50 cm, root cylindrical and slender, brownish-yellow. Above-ground stems grow in clusters from the base, upright or slanting. Leaves are simple, linear and alternate, hairless. Racemose inflorescence grows at the top of the stem. Flowers are small and sparsely arranged, greenish-white with purple edges. Seeds are ovate, grayish-black, with white fuzz. Flowering period is April-July, fruiting period is May-August.
Site Selection and Bed Preparation: Sandy and clay loam soils with deep, fertile layers are both suitable for planting. After selecting the site, apply 100 kg of calcium superphosphate, 50 kg of potassium carbonate, 50 kg of ammonium hydrogen phosphate, and 3 cubic meters of decomposed farmyard manure per mu, then deep-plow more than 25 cm. Level the soil and make wide beds. Evenly spray trifluralin on the soil surface (500 g covers 1.5 mu), then water immediately. After 5-7 days when the surface soil becomes loose, rake the bed surface level.
Sowing Method: In the leveled bed, sow evenly by hand or with a seeder at a row spacing of about 20 cm, then tread over it once and cover with a layer of wheat chaff. Polygala can be sown and emerge from Qingming to the Spring Equinox. The seeding rate is 1.5-2 kg per mu.
Field Management: Keep the bed moist before emergence. Generally, seedlings emerge in 7-10 days. After the seedlings emerge and have 6-8 true leaves, spray once with tebuconazole, and spray again after 15-20 days, mainly to prevent and control leaf rust and leaf blight. At the same time, spray jingkecholuron or gaicaoluron at one bag per mu, and use kuaichu spray to clear small weeds. Generally, no topdressing is applied in the first year. In April of the second year, apply 100 kg of calcium superphosphate and 15-20 kg of urea per mu to supplement soil fertility and increase yield. Polygala generally has few pests and diseases. In the rainy season, pay attention to drainage in low-lying areas with standing water to prevent root rot. Polygala is drought-tolerant and generally does not need watering unless conditions are dry.
Harvesting and Processing: After several years of growth, when the middle part of the root reaches a diameter of more than 0.5 cm, harvest in mid-October. Place the fresh roots in a cool, ventilated place and pile them for two days before processing. Select thick, uniform roots and rub them back and forth on a flat surface until the bark and flesh separate from the woody core. Remove the woody core and sun-dry. Because it forms a tube shape, it is called “polygala tube.“
Yield-Increasing Measures: Polygala has slender stems and leaves, a very small leaf area, and slender roots, with slow early growth. However, reasonable close planting and making full use of soil fertility are key to increasing yield. Polygala has a long growth period, so applying sufficient base fertilizer and topdressing is very important.
Through domestic cultivation with reasonable close planting, the yield is high and the quality is good. Polygala tubes can reach more than 80 yuan per kg. They are largely purchased in bulk by foreign trade for export. Only substandard polygala tubes and polygala flesh are supplied to the market, at prices of 30-50 yuan.