Detailed Explanation of High-Quality and High-Yield Cultivation Techniques for Pinellia ternata
Pinellia ternata is a commonly used precious traditional Chinese medicine, and its commercial supply mainly relies on harvesting wild resources. In recent years, due to changes in the environment, climate, and resources, the contradiction between supply and demand has become increasingly tense. Because cultivation development has been slow, the market has long been in short supply, and prices have remained stable and continued to rise. In many places, Typhonium flagelliforme (water pinellia) is used as a substitute. In southern provinces such as Jiangxi and Guangxi, cultivation of Typhonium flagelliforme has appeared. The state has repeatedly ordered that Typhonium flagelliforme be listed as a counterfeit, prohibiting pharmaceutical factories from using the counterfeit Typhonium flagelliforme to replace Pinellia ternata as a raw material. For various reasons, its wild resources are being dug up less and less, resulting in shortage. Artificial cultivation, due to problems such as low reproductive capacity and variety degeneration, has limited the improvement of yield and quality and cannot timely supply the strong market demand. The amount available on the market decreases year by year, while domestic medicinal demand and export volume increase significantly year by year. Its selling price keeps rising. In the winter of 2005, the medicinal market offered 55-65 yuan/kg, up 33.3% from the same-period price of 45 yuan. Both export and domestic sales are in tight demand, and there are still not many goods available, making it a hot variety in medicinal market transactions, with good market and cultivation prospects. Traditional methods of cultivating Pinellia ternata generally yield 500-750 kg of fresh tubers per mu, with a drying ratio of 25%-30%, and an annual yield of 125-200 kg. However, according to high-yield practical experience in producing areas, high-yield fields have an average tuber yield of 850-1500 kg fresh weight, an increase of 50%-100%, a significant yield increase, with an output value of more than 10000 yuan per mu and considerable benefits. Therefore, for medicinal farmers to obtain higher yields and high benefits from cultivating Pinellia ternata, in addition to good routine field management, they must also grasp the following key links:
Intercropping and Relay Cropping Increase Benefits
According to the biological characteristics of Pinellia ternata, develop production according to local conditions. Pinellia ternata prefers warm and humid climates, can tolerate cold and shade, but is not drought-tolerant and fears strong light. Using this characteristic, Pinellia ternata can be interplanted on gently sloping mountain land with half shade and half sun, or in wheat fields or broadleaf fruit tree forests, and can also be intercropped with tall-stemmed plants such as corn, rapeseed, sorghum, and beans. In this way, Pinellia ternata is managed while managing crops or economic forest fruits, which not only rationally uses the land but also increases comprehensive benefits.
Carefully Cultivate Fine Varieties
Excellent seeds are an important guarantee for achieving high yields in Pinellia ternata cultivation. So what are the quality conditions that determine excellent seeds? First, select excellent individual plants with pure variety, no pests or diseases, and robust growth as mother plants for seed collection. Second, the mother plants used for seed collection should be cultivated separately, and water and fertilizer management should be strengthened. Third, to prevent variety mixing, separate harvesting and separate storage should also be carried out. Finally, timely harvest mature, plump, large, and heavy tubers as seeds. Apply modern biological methods to tissue culture the excellent Pinellia ternata seed balls obtained through careful selection and breeding, establish a rapid asexual propagation system for excellent Pinellia ternata varieties, and screen out Pinellia ternata varieties with excellent traits. This can not only produce excellent Pinellia ternata seedlings in large quantities but also shorten the field growth period. Then combine the use of bulbils and tubers for propagation to increase the propagation coefficient.
Cover with Film in Early Spring for Earlier Seedling Raising
According to experiments, when sprouting is promoted at 20-25°C, and when most bud sheaths turn white, planting and covering with plastic film results in seedlings emerging 30 days earlier than planting without either sprouting promotion or film covering; without sprouting promotion but with only film covering, seedlings emerge 25 days earlier. At the same time, sprouting promotion plus film covering increased yield by 52.6% compared with the control, and without sprouting promotion but with only film covering increased yield by 29.8% compared with the control. Planting after buds are sprouted allows Pinellia ternata planting material to complete the internal physiological changes before germination in advance. Covering with plastic film increases ground temperature and reaches the temperature required for seedling emergence earlier, so buds quickly grow out of the ground. In addition to preserving moisture, increasing temperature, and advancing seedling emergence, sprouting promotion plus film covering also makes the soil loose and well aerated, which is more conducive to root growth and development, enabling plants to resist drought and waterlogging and always maintain vigorous absorption and physiological functions, laying the foundation for tuber enlargement and high yield of Pinellia ternata.
The plastic film used can be ordinary agricultural plastic film (thickness 0.014 mm), or high-density film (thickness 0.008 mm). When covering with film, make the film flat and closely attached to the ridge, and compact it with soil, achieving tightness, flatness, and strictness. When the temperature stabilizes at 15-18°C and about 50% of seedlings have emerged, the plastic film should be removed to prevent high temperatures inside the film from scorching young seedlings. Before removing the film, seedling hardening should be carried out first. The method is to uncover both ends of the ridge at noon for ventilation and heat dissipation, then seal them in the evening, and after several consecutive days remove the film completely.
Cover the Bed Surface During High-Temperature Period to Delay Seedling Dieback
When gradually entering the high-temperature season in late June, how to keep the bed surface moist and delay the withering of the aboveground part of Pinellia ternata as much as possible is an important measure to increase Pinellia ternata yield. According to experiments, covering with rice and wheat straw (chaff) in mid-May and mid-June respectively each year resulted in only 5% seedling dieback in late July and good growth, while the control group had 78% seedling dieback. In this way, covering relatively prolongs the growth period, and the photosynthesis period is also relatively prolonged. More photosynthetic products accumulate in tubers, and the produced tubers grow large and have high yield, increasing yield by 123.78% compared with the control. Moreover, weeds in the covered area were significantly reduced compared with the uncovered control area, and the incidence of leaf rot was significantly reduced, which is also an important reason for increased Pinellia ternata yield. If rainfall is heavy and the flood season is continuously rainy, with excessive soil moisture, not only should the second covering not be applied, but the wheat straw applied the first time should also be removed in time to prevent underground tuber rot and yield reduction.
Intertillage and Weeding to Prevent Weed Damage
Pinellia ternata plants are short, and during the growth period they should be loosened and weeded frequently to avoid weed overgrowth. The depth of intertillage should not exceed 5 cm to avoid damaging roots. Because the roots of Pinellia ternata grow around the tubers, and its root system is concentrated in the 12-15 cm surface soil layer, intertillage should be shallow rather than deep, and weeds should be removed early, when small, and completely. When Pinellia ternata is planted in early spring and covered with plastic film, along with its seedling emergence, more than 10 kinds of weeds such as foxtail grass, crabgrass, goosegrass, lovegrass, nutgrass, amaranth, small bindweed, lamb's quarters, and purslane also emerge, and in large quantities, often causing difficulty in seedling emergence and growth after film removal and affecting Pinellia ternata yield. Therefore, acetochlor can be selected to control pre-emergence weeds of Pinellia ternata. Spraying herbicide on the ground in early spring and then covering with plastic film has a good control effect on many weeds (for specific usage and dosage, follow the drug instructions). In addition, in artificial cultivation of Pinellia ternata, different herbicides can be selected according to different seasons. For spring-planted Pinellia ternata, fluazifop-P-butyl is suitable, and for autumn planting, either fluazifop-P-butyl or acetochlor can be used.
Spray Medicinal Fertilizer to Promote High Yield
Practice shows that spraying sodium sulfite solution during high-temperature and drought periods can increase Pinellia ternata yield. This is because when the summer temperature continuously reaches as high as 30°C, due to high temperature and strong light, the respiration of Pinellia ternata becomes too strong, and the substances consumed exceed those accumulated by photosynthesis, leading to destruction of the protoplasmic structure of cells and "seedling dieback." For Pinellia ternata production, "seedling dieback" shortens the growth period of Pinellia ternata and seriously affects its yield. Therefore, taking measures in production to delay or reduce summer "seedling dieback" of Pinellia ternata is an important condition for achieving high yield and high quality. In cultivation, in addition to appropriate shading and sprinkler irrigation to reduce light intensity, air temperature, and ground temperature, a 0.01% sodium sulfite solution, a plant respiration inhibitor, can also be sprayed, or a mixed solution of 0.01% sodium sulfite, 0.2% urea, and 2% superphosphate can be sprayed to inhibit the respiration of Pinellia ternata and reduce the consumption of photosynthetic products, thereby delaying and reducing "seedling dieback" and achieving obvious yield-increasing benefits.
Implement GAP Standardized Planting
According to GAP requirements, implement standardized management of the entire process of Pinellia ternata seeds, seedlings, pesticides, chemical fertilizers, water, soil, density, protection, management, labor, and planting, harvesting, processing, packaging, storage, and transportation, limit the content of harmful elements and pesticide residues in Pinellia ternata medicinal material, and use advanced planting and processing techniques to improve the yield and quality of Pinellia ternata.