High-yield cultivation and field management techniques for Pinellia ternata (dryland Pinellia)
Selection of the planting site
Dryland PinelliaIt prefers a mild and humid climate, is tolerant of cold and shade, and is suitable for cultivation on hillsides and flat land. It can be intercropped with fruit trees, and can also be intercropped with tall-stemmed plants such as corn, rapeseed and wheat. Sandy soil is best for planting; heavy clay and low-lying, waterlogged plots are not suitable for planting.
The suitable sowing period for planting dryland Pinellia is from November in winter to April of the following spring. Before sowing, in combination with land preparation, apply 2000 kg of barnyard manure or compost and 25 kg of superphosphate per 667 sq m, and plow them into the soil as base fertilizer. At sowing time, plow and turn the soil once more, then break it up finely and rake it level to make beds. Dryland Pinellia is mainly propagated by tubers and main buds. When propagating by tubers, it is best to plant them immediately after digging. Dig holes at a row spacing of 17-20 cm and a plant spacing of 7-10 cm, plant 2-3 tubers per hole, and use 40-50 kg of tubers per 667 sq m. Do not cover with soil too thickly; 1-2 cm is appropriate. After covering with soil, if the soil is dry, water promptly. When propagating by bulbils, in summer and autumn, when the old leaves are about to wither and the bulbils under the leaf stalks have matured, take the mature bulbils and plant them in rows, with the same row and plant spacing as for tuber propagation.
High-yield field management techniques
1. Timely topdressing
Pinellia is a fertilizer-loving plant. After the seedlings emerge, carry out the first topdressing, applying 1000-2000 kg of decomposed human and animal manure per mu, and thereafter carry out multiple topdressings according to seedling growth. After Grain Full, when the first batch of bulbils has grown many new plants, the plant density in the field increases, and the corms grow rapidly, requiring more water and fertilizer. In addition, apply heavy applications of manure, cake fertilizer and urea: apply 4000-5000 kg of a mixed fertilizer of decomposed barnyard manure and grass peat ash per mu, plus 50 kg of peanut bran (crushed and composted), broadcast on the bed surface. After fertilizing, earth up immediately to prevent fertilizer loss.
2. Irrigation, drainage and earthing up
High temperatures and dry soil often cause the plants to turn yellow and wither, or even to collapse, directly affecting tuber growth. Therefore, throughout the entire growth and development period of Pinellia, the soil should be kept moist regularly to promote plant and tuber growth; in the rainy season, drainage work should be done well to prevent corm rot.
After June each year, the mature seeds and bulbils fall to the ground one after another. It is advisable to earth up twice from Grain in Ear (early June) to Minor Heat (early July), to help the bulbils enter the soil and grow into new, robust plants. For earthing up, take soil from the edge of the bed, break it up, and spread it evenly over the bed surface to a thickness of about 1.5 cm, then smooth the soil with the hands to prevent water accumulation.
3. Timely bud removal
In order to promote corm growth and reduce nutrient consumption, when the plants bolt, remove the flower buds that emerge in stages and batches. In addition, Pinellia has strong reproductive capacity; after the bulbils fall to the ground, they grow extremely fast and are not easy to remove. Therefore, when the spathe emerges, it must be removed so that the corm accumulates more nutrients, thereby increasing the yield of Pinellia.
4. Pest and disease control
① Corm rot.
It generally occurs in the rainy season and in low-lying waterlogged places. After onset, the corm rots and the aboveground stems and leaves wither. Control methods: pay attention to drainage, pull out diseased plants in the early stage of the disease, and pour 5% limewater into the diseased plants and diseased holes, or scatter lime powder at the diseased holes to prevent the disease from spreading.
② Leaf curl disease.
A disease caused by a virus, mostly occurring in summer. After onset, the leaflets shrink and twist, and the plants become shorter and deformed. Control methods: first, thoroughly eliminate the aphids that spread the disease source; second, select disease-free plants for seed retention.
③ Aphids.
Their adults and larvae suck the sap of tender leaves and tender buds, causing the leaves to turn yellow and plant growth to be hindered. Control methods: first, during the aphid outbreak period, spray with a 1500-2000 times dilution of 40% dimethoate emulsifiable concentrate; second, spray with a 1000-1500 times dilution of menazon (Mieyaling) to kill them.
④ Cabbage caterpillars.
Their larvae bite and eat the leaves, causing holes and gaps; in severe cases, entire leaves are eaten up. During the outbreak period, spray with a 1500 times dilution of 90% trichlorfon or a 1000 times dilution of dichlorvos to kill them.
5. Harvesting and processing
① Timely digging and harvesting:
The harvest time of Pinellia has a great impact on yield and product quality. Digging and harvesting at the right time makes processing easy for peeling, fast drying, and produces goods that are white in color, sufficiently starchy, and high in dry-to-fresh ratio. Digging too early results in insufficient starchiness and affects yield. Digging too late not only makes peeling difficult and drying slow, but the starch in the tubers has already decomposed, so the processed goods have poor starchiness, are not white in color, and are prone to producing "rigid tubers" (hornification), with poor quality and even lower yield. Digging and harvesting after the plants collapse takes more than three times the labor. The results of many years of research on artificially cultivated Pinellia show that the best digging and harvesting period for Pinellia should be in autumn when the temperature drops below 13 degrees and the leaves begin to turn yellow-green; in the Huang-Huai region, 13 degrees occurs around the time of the Autumn Equinox; in the Yangtze River basin, it should be appropriately postponed according to temperature differences; in various places in Northeast China, where temperatures are lower, digging and harvesting should be appropriately advanced.
② Digging and harvesting methods:
At harvest time, if the soil moisture is too high, first loosen the tubers and soil together to let the soil moisture evaporate faster and make the soil dry as soon as possible, so as to facilitate digging and harvesting. When digging and harvesting, from one end of the bed, follow the rows and use a claw hook or iron pick to turn the whole Pinellia plant with leaves to one side, and carefully pick out the tubers. The bulbils that fall on the ground after the plants collapse should be picked out before digging and harvesting. The dead leaves and residual branches left in the ground after digging and harvesting should be picked out and burned to reduce the occurrence of pests and diseases the following year.
③ Processing techniques:
(1) Fermentation:
Pile the harvested fresh Pinellia tubers indoors to a thickness of 50 cm and leave them piled for 15-20 days. Upon inspection, if the outer skin of the Pinellia is slightly rotten and easily comes off when gently rubbed by hand, it is ready.
(2) Peeling:
Separate the fermented Pinellia tubers by sieve into three grades: large, medium and small. For small quantities, manual peeling can be used. The method is to put the Pinellia tubers separately into woven bags or other containers, wash them with water, then step on them wearing rubber boots or rub them back and forth repeatedly by hand for 10 minutes, pour them into a sieve and rinse away the broken skin with water. Pick out any that have not been fully peeled and rub them again until all are fully peeled. If the larger tubers, after peeling, still have a small round transparent "cocoon" at the bottom (commonly known as the "rear opening"), for small quantities it can be peeled off by hand; for large quantities, put them back into bags and rub them off until all Pinellia tubers are pure white. For Pinellia bases with a larger area, mechanical peeling can be used.
(3) Drying: After peeling, the Pinellia must be dried immediately, preferably in direct sunlight, and turned constantly. At night, bring them back indoors and spread them out flat to air-dry, then take them out the next day and sun-dry until completely dry, and they become a marketable product. If the quantity of Pinellia is relatively large, it is best to build a drying room, so that peeling and drying can proceed together without being affected by the weather, and the processed Pinellia product is of better quality.