Detailed Explanation of Polygala tenuifolia Planting Techniques and Management Points

I. Growth Characteristics

Polygala tenuifolia prefers a cool climate, tolerates drought, and dislikes high temperatures. It grows mostly wild in relatively dry fields, roadsides, hillsides and other places. It is best cultivated in sunny, well-drained sandy soil, followed by clay loam and calcareous loam. Clay soil and low-lying wet areas are not suitable for planting.

II. Cultivation Techniques

1. Site Selection and Land Preparation

Choose a site with high, dry terrain and good drainage; generally any land can be used for planting. Before land preparation, spread base fertilizer. Since Polygala tenuifolia is a perennial herb, sufficient base fertilizer must be applied. Commonly, 37500 kg of barnyard manure or compost per hectare and 750 kg of superphosphate are used, then plowed and harrowed level. In northern regions, flat-field drilling is mostly adopted.

2. Propagation Methods

Seed propagation is used, either by direct seeding or by raising seedlings and transplanting. Because the capsules of Polygala tenuifolia split open when mature and the seeds easily scatter on the ground, seeds should be harvested when the fruits mature in July to August.

A. Direct Seeding: Spring sowing is done in mid-to-late April, and autumn sowing in mid-to-late October or early November. On the prepared land, spread the seeds evenly into furrows and cover with 1-2 cm of soil. Drill in shallow furrows with a row spacing of 20-23 cm, at a seeding rate of 11.25-15 kg per hectare. After sowing, press lightly and water thoroughly. Seedlings begin to emerge about half a month after sowing. Autumn-sown seeds emerge in the spring of the following year.

B. Seedling Raising: In early-to-mid March, drill seeds in a seedbed and cover with 1 cm of soil; keep the seedbed moist, with a suitable seedbed temperature of 15-20°C. Seedlings emerge about 10 days after sowing. When seedlings are about 6 cm tall, they can be transplanted. Transplanting should be done on cloudy and rainy days or in the afternoon, with a row spacing of 20-23 cm and a plant spacing of 3-6 cm.

3. Field Management

Polygala tenuifolia plants are short, so frequent weeding is needed during the growing period to prevent weeds from covering the plants. Because it prefers dry conditions, apart from appropriate watering during seed germination and the seedling stage, frequent watering is not needed in the later growth stage. Apply topdressing once each in spring, winter, and between April and May every year to increase root yield. Phosphorus fertilizer is the main type; 300-375 kg of cake fertilizer per hectare, or 187.5-262.5 kg of superphosphate, can be applied. For potassium fertilizer spraying, mid-June to early July each year is the peak growth period of Polygala tenuifolia. At this time, spray 750-900 kg of 1% potassium sulfate solution or 1200-1500 kg of 0.3% potassium dihydrogen phosphate solution per hectare, once every 10 days, for 3 consecutive times. Spray in the early morning when dew has not dried or at 5 p.m. in the evening to enhance disease resistance and promote root enlargement.

For one-year-old seedlings after loosening soil and weeding, or for seedlings grown for 2-3 years, after topdressing and watering, cover with 12000-15000 kg per hectare of wheat straw, wheat bran, sawdust or similar materials, spread along the rows, without turning until harvest. Covering with straw enhances the decomposition of microorganisms in the soil, maintains moisture, reduces weeds, and creates good conditions for the growth of Polygala tenuifolia.

4. Pest and Disease Control

Root rot: causes root rot of Polygala tenuifolia and wilting of the plants.

Control method: Strengthen field management, pull out diseased plants early and burn them, and disinfect the diseased holes with 10% lime water. In the early stage of the disease, spray 50% carbendazim 1000-fold solution, once every 7 days, for 2-3 consecutive times.

Note: For aphids, spray with 40% dimethoate 2000-fold solution, once every 10 days, for 2-3 consecutive times. For bean blister beetles, spray with deltamethrin at 5*10 to the power of -6 to 1*10 to the power of -5, spraying twice consecutively with an interval of 5-7 days.