Detailed Explanation of Key Techniques for High-Ridge Cultivation of Chinese Yam

Chinese yam, also known as shuyu (Dioscorea), is a perennial herbaceous vine. It prefers dry conditions and fears waterlogging, and is suitable for growing in environments with ample sunlight, a warm climate, and relatively dry conditions. The optimum temperature for germination is around 15°C, and the optimum temperature for growth is 17-28°C. Generally, a slightly acidic sandy loam soil with deep, loose soil should be selected.

1. Variety selection: Choose varieties with good quality, high yield, strong stress resistance, wide adaptability, and good marketability, such as Henan Huaishan yam and Jiangsu vegetable yam. 2. Land preparation and ridge making: Before winter, dig planting trenches at a trench spacing of 50 cm, a depth of 100 cm, and a width of 50 cm. In early spring of the following year, fill the trenches with soil in stages, first filling with raw soil and then with mature soil, and apply sufficient base fertilizer. Generally, apply 4000-5000 kg of decomposed organic fertilizer, 30 kg of superphosphate, and 20 kg of potassium sulfate per mu. Then make high ridges 70 cm wide, 30 cm high, and 30 cm apart. 3. Seed selection and seed sunning: 1. Replacement bud propagation method: Select disease-free, rot-free, healthy, and plump yam buds. Sun the seeds 10-15 days before sowing. 2. Rhizome propagation method: Select seed stem segments free of pests and diseases with a diameter of more than 3 cm and a length of 15-20 cm, coat both cut ends with quicklime or plant ash for antisepsis, and sun the seeds 15-20 days before sowing. 4. Trenching and planting: During the period from Qingming to Guyu, adopt wide-and-narrow row planting. Make narrow rows on the ridge surface, and make wide rows between adjacent ridges. Planting method: Open 2 planting trenches 10 cm deep and 30 cm apart on the ridge surface, with wide rows 70 cm and narrow rows 30 cm, place the seed stems flat in the trenches at a plant spacing of 20-25 cm, with the sprouting buds facing one direction, plant 6000 plants per mu, and cover with soil about 8-10 cm. 5. Field management

1. Thinning seedlings and pruning branches: After the Chinese yam emerges, promptly thin out clustered seedlings and weak seedlings, keep 1-2 robust seedlings per hole, and remove side branches at the base of the main stem. During the formation of “bulbils”, to avoid excessive nutrient consumption, some may also be removed early. 2. Intertillage and weeding: Combine topdressing with intertillage and weeding. Intertillage should be shallow to avoid damaging the root system. Weeds near the plants can be pulled out by hand. 3. Trellising and vine guiding: When the Chinese yam begins to send out vines, trellises should be set up promptly. Generally, Chinese yam trellises are 1.5-2.5 m high, and A-shaped trellises are mostly used. 4. Fertilizer and water management: During the vine growth stage, apply 15 kg of urea per mu as topdressing. Chinese yam is drought-tolerant and fears waterlogging. During the peak tuber growth stage, keep the soil moist; do not irrigate unless there is drought, and drain promptly after rain. 6. Pest and disease control: The main pests of Chinese yam are cutworms, grubs, and leaf-eating insects. For underground pests, control can be carried out by deep plowing before winter, applying more decomposed organic fertilizer, and combining with 50% Lebiqiben emulsifiable concentrate diluted with water for root irrigation. Use 2.5% Decis 2000-fold solution or 3% phoxim 1200-fold solution alternately for spray control of leaf-eating insects. The main diseases of Chinese yam are anthracnose, nematode disease, and brown spot. For control, crop rotation, changing seed tubers, soil disinfection to eliminate diseased residues, applying decomposed organic fertilizer, and chemical control can be used. 7. Harvesting and storage: In late October, the tubers of Chinese yam basically stop growing, and when the leaves dry up, they should be dug promptly to prevent rot. After harvest, store in cellars or indoors, as long as they are not damaged by low-temperature freezing.