Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Pinellia ternata
Site Selection and Land Preparation Pinellia ternata prefers a warm, humid environment. It is best to choose loose, fertile, moist sandy loam with irrigation and drainage conditions, with a soil pH of 5.5-6.8. Pinellia ternata likes fertilizer, so before sowing, while preparing the land, apply base fertilizer. Apply 2500-4000 kg of decomposed organic fertilizer or farmyard manure and 15-20 kg of superphosphate per mu as base fertilizer, plow 20 cm deep, harrow finely and level, and make beds 1 m wide. The length should not exceed 20 m to facilitate irrigation and drainage.
Sowing In production, tubers and bulbils are mostly used for propagation. Seedling raising from seeds or asexual rapid propagation by tissue culture can also be used. Tuber propagation and bulbil propagation gain weight quickly, and a harvest can be obtained in the same year. Select tubers 0.5-1.5 cm in diameter from the current year as seed tubers. Generally, sowing is suitable in spring when the average temperature is about 10°C. In the prepared bed, open furrows 4-5 cm deep at a row spacing of 20 cm. The bottom of the furrow should be flat. Place the seed tubers into the furrow at a plant spacing of 4 cm with the apical bud facing upward, cover with soil and level it, and press lightly. If the soil is dry after planting, water promptly. Use about 60 kg of seed tubers per mu. It can also be planted in autumn, generally from mid-to-late September to mid-October, using the same method as spring sowing.
Field Management
(1) Irrigation and drainage. After sowing, seedlings generally emerge in spring in 20 days. In case of severe drought, water appropriately to ensure full stands. After the seedlings are fully established, control watering to prevent excessive aboveground growth and promote the growth and development of the underground part.
(2) Topdressing and earthing up. After the seedlings are fully established, loosen the soil and hoe weeds promptly, and apply diluted human urine once. From late May to late June, bulbils grow relatively quickly. When the bulbils have formed and begin to fall off, apply 500-1000 kg of barnyard manure mixed with 5 kg of urea per mu and scatter it into the furrows, and earth up the soil between rows onto the Pinellia ternata seedlings, just enough to cover the bulbils. After June, the bulbils on the petioles mature and fall to the ground, and the seeds also mature successively and fall to the ground as the plants wither. Earth up 2-3 times as appropriate. Take fine soil from the bed furrows, scatter it on the bed surface about 1.5-2 cm thick to cover the bulbils and seeds, then pat it firm with an iron shovel. Between Major Heat and Beginning of Autumn, apply diluted human urine plus a small amount of superphosphate once. In early to mid-September, mix 10 kg of urea and 20 kg of superphosphate with soil and evenly scatter it on the surface soil to provide earthing up and grain filling effects, which can significantly increase yield.
(3) Intertillage and weeding. After the seedlings emerge fully, remove weeds promptly. Use a small hoe for shallow hoeing between rows, and the depth must not exceed 3 cm.
(4) Shading. In production, corn and legume crops can be intercropped along the bed edges in mid-to-late April. In early to mid-June, the intercrops grow tall or trellises are set up for shading. After September, as the temperature gradually drops, the intercrops should be harvested promptly.
(5) Bud removal. Except when seed propagation is needed, all flower buds produced during the growing period should be removed to reduce nutrient consumption and promote the enlargement of the underground part.
Pest and Disease Control
(1) Root rot. It is prone to occur under high temperature and high humidity. After onset, the underground tubers rot, and the aboveground part then collapses and dies. Control methods: pay attention to drainage, pull out diseased plants and treat the diseased holes with 5% lime water or pour it on the roots. It is also possible to soak seed tubers in 0.5%-2% lime water for 12-30 hours before sowing.
(2) Leaf spot. When the disease occurs, there are purplish-brown lesions on the leaves, and the plants gradually wither afterward. Control methods: before onset and in the early stage of onset, spray 65% zineb 500-fold solution once every 7-10 days, for 2-3 consecutive times.
(3) Viral disease. Diseased plants have leaves that curl into a mosaic pattern, and the plants are short and deformed, mostly occurring in spring and summer. Control methods: remove diseased plants to eliminate sources of infection; select disease-free plants for seed retention.
(4) Red hawk moth. The larvae damage leaves, biting them into notches or eating the leaves completely. Control methods: spray 90% trichlorfon 800-fold solution during the young larval stage or handpick them.
Harvesting and Processing Tuber propagation can be harvested in the same year. Harvest in late September when the leaves turn yellow and withered. Dig out the tubers and grade them into large, medium, and small. The large ones are processed into commercial products, while the medium and small ones are used as seed tubers for continued planting. Fresh Pinellia ternata that needs processing after harvest should be peeled promptly; if piled too long, peeling becomes difficult. Because raw Pinellia ternata is toxic, contact between hands, feet, and skin with Pinellia ternata should be strictly avoided. Pinellia ternata used as seed can be stored over winter by sand storage.