Detailed Explanation of Key Cultivation Techniques for Pinellia ternata in Yuelai Township

Pinellia ternata is a perennial herbaceous plant of the Araceae family. Its tubers are used as medicine; it is toxic and has the effects of drying dampness and resolving phlegm, directing qi downward and stopping vomiting, and dispersing masses and eliminating stagnation. It mainly treats damp phlegm and cold fluids, vomiting, nausea, coughing and wheezing with copious phlegm, abdominal and diaphragmatic distension, dizziness and insomnia, and externally reduces swelling and pain.

Yuelai Township, Anyue County, Sichuan Province, is located in the western part of Tongxian District, in the submerged area of Shufangba Reservoir, surrounded by water on three sides; the entire township consists of shallow hilly slopes with fertile, moist soil, a loose sandy neutral to slightly acidic soil, and no environmental or atmospheric pollution, with excellent water quality. Mulberry fields with half shade and half sun are most suitable for intercropping Pinellia ternata.

1. Selecting Good-Quality Seed Stock

Selecting high-quality seed stock is the foundation of high yield. Seed tubers that are firm in texture, plump in the spearhead shape, and that show sticky milky-white mucus on the cut surface should be used as seed stock. Remove seed tubers with moldy seed coats, soft texture, or deterioration. In some fields, although seed tubers are only partially rotted and can still take root and sprout after planting, they are prone to disease during the seedling stage and easily cause contamination, so they cannot be used as seed.

2. Site Selection and Land Preparation

Pinellia ternata has shallow roots, prefers a mild and moist climate, is afraid of drought, and avoids high temperatures. It is suitable for planting in moist, fertile, deep sandy land or sandy soil with good drainage, and gentle-slope mountainous land with half shade and half sun may also be chosen. Yuelai Township consists of shallow hilly slopes, and intercropping Pinellia ternata in mulberry fields with half shade and half sun gives good results. For winter sowing or early spring sowing, the land should be plowed as early as possible to facilitate soil weathering and decomposition. Plowing should not be too deep; 15-20 cm is sufficient. Level the ground and remove weeds.

3. Fertilization

Pinellia ternata is a heavy feeder and requires loose soil, so sufficient organic fertilizer must be applied. Decomposed human and livestock manure and urine, plant ash, and the like may be used, supplemented with decomposed wheat straw, cottonseed, rice straw, and a small amount of chemical fertilizer mixed evenly with fine sandy soil as a base fertilizer.

4. Sowing

Most Pinellia ternata planted in Yuelai Township is sown in winter, using the method of broadcasting tubers.

After leveling the ground, broadcast the seed tubers on the prepared beds. There are 3 spacing categories between seed tubers: those with a diameter above 0.8 cm at 6-8 cm, those with a diameter of 0.5-0.8 cm at 4-6 cm, and those with a diameter below 0.5 cm at 2-3 cm. After broadcasting, cover with fine fertilized soil and water to settle the roots. After covering with soil, the bed furrows form naturally. Covering with plastic film can raise the ground temperature and bring about earlier emergence.

5. Field Management

Field management of Pinellia ternata is an important part of increasing yield and quality and preventing pests and diseases.

5.1 Removing the Plastic Film

When the ground temperature is above 15°C or more than 50% of the Pinellia ternata plants have grown 1 leaf, the film can be "broken to release the seedlings" to prevent excessively high temperatures inside the film from scorching the young seedlings; thereafter, water in a timely manner.

5.2 Cultivation and Weeding

When Pinellia ternata emerges is also when weeds grow; if they are not removed in time, the seedlings will have difficulty growing and yield will be affected. Pinellia ternata plants are short, so during the growing period the soil should be loosened and weeds removed frequently to avoid weed infestation. Cultivation depth should not be too deep; no more than 5 cm is advisable to avoid damaging the roots. After weeding, fertilize in a timely manner.

5.3 Removing Flower Bolts

Except in fields kept for seed production, the flower bolts produced during the growing period of Pinellia ternata should be removed in a timely manner so that nutrients are concentrated in the underground tubers and yield is increased.

5.4 Water and Fertilizer Management

Pinellia ternata likes moisture and fears drought; before emergence, give 1 thorough watering to promote emergence. During the growing period, water appropriately according to soil moisture conditions. If it is too dry, Pinellia ternata is prone to seedling collapse; if it is too wet, root rot, stem rot, and collapse and death of seedlings readily occur. Therefore, pay attention to timely drainage; irrigation has an important effect on delaying the collapse of Pinellia ternata and increasing yield.

Pinellia ternata is a fertilizer-loving plant, so during the growing period attention should be paid to applying more fertilizer appropriately, mainly farmyard manure; especially after seedling collapse during the growing period, topdressing should be emphasized, mainly with human and livestock manure water. About 1000 kg per mu each time is advisable. In the later stage of growth of Pinellia ternata, the demand for phosphorus and potassium is relatively high. Mix an appropriate amount of superphosphate and potassium fertilizer evenly, stir with ditch mud, and scatter it on the soil surface, which can serve the functions of earthing up and grain filling.

5.5 Earthing Up

Earthing up helps preserve soil moisture in Pinellia ternata fields and drain water from the field. Earthing up can turn flat beds into raised beds and turn bed ridges into small furrows, which helps drainage during the rainy season and helps prevent tuber rot; at the same time, earthing up also helps with weeding.

5.6 Other

When the summer temperature remains as high as 30°C, Pinellia ternata will show seedling collapse. Seedling collapse is an adaptation by which Pinellia ternata resists high temperature and strong light, and it plays a positive role in preserving and continuing the life of Pinellia ternata. However, in terms of production, seedling collapse shortens the growing period. In production, in addition to shading and sprinkler irrigation for cooling and sun protection, an appropriate amount of sodium bisulfite (0.01%) solution may also be sprayed to inhibit respiration in Pinellia ternata, reduce consumption of photosynthetic products, and produce an obvious yield increase.

6. Pest and Disease Control

Pests and diseases of Pinellia ternata mostly occur in the hot, humid summer. The main ones are leaf spot disease, rot disease, viral disease, and the red hawk moth. For leaf spot disease, garlic 1 kg added to water 20-25 kg may be sprayed; diseased plants found should be pulled up and burned. Viral disease: select disease-free plants for seed as far as possible and control human transmission; carry out reasonable crop rotation and apply sufficient organic fertilizer to enhance disease resistance; pull up diseased plants and burn them together to prevent spread. Rot disease: pay attention to timely dredging of ditches and drainage during the rainy season and after heavy rain; before planting, soak the seed in 5% plant ash solution or 50% carbendazim 1000-fold solution. Red hawk moth: remove by hand-catching or trap and kill adults with black light lamps.