How to grow Chinese yam for high yield? These techniques must be mastered

Chinese yam has high nutritional value, with functions such as strengthening the spleen, tonifying the lungs, consolidating the kidneys, and boosting essence, and it has therapeutic effects on some diseases of the elderly, so market demand is increasing year by year. So how do you grow Chinese yam? Let's take a look at high-yield Chinese yam techniques.

1. Select excellent varieties of Chinese yam seed

To produce high-quality Chinese yam, it is advisable to choose new varieties with disease resistance, strong stress resistance, tolerance to fertilizer and water, high yield, good quality, and good storability, such as Zhenping Chinese yam, thick ox-leg Chinese yam, Nongda Long Chinese Yam No. 1, Nongda Flat Chinese Yam No. 1, Nongda No-trellis Chinese Yam, Japanese White Chinese Yam, Tianyuanjia Chinese Yam, Huazi Chinese Yam, and Japanese Yamato Imo.

2. Choose high-quality plots for planting

Choose plots with high terrain, convenient drainage and irrigation, and shelter from wind and facing the sun; the groundwater level is required to be below 4 m, the plow layer more than 20 cm thick, and sandy loam soil containing 2% organic matter and 0.15% total nitrogen is considered high-yield field. Chinese yam is extremely averse to continuous cropping, especially repeated trench planting, which easily causes serious diseases and reduces yield due to soil nutrient imbalance. According to surveys, continuous cropping for two years reduces yield by more than 30%, and continuous cropping for 3 years reduces yield by 40%-50%.

3. Use the trenching and fertilization method

Deeply plow 30 cm before winter to promote soil maturation. In mid-February of the following year, dig trenches at a row spacing of 0.9-1 m, with a trench depth of 1.4 m and a width of 0.25 m. After digging, immediately backfill soil into the trench, and when backfilling, be careful to remove the sticky clay from the trench. Backfill every 30 cm of soil and tread it down once to prevent the bed surface from collapsing during the rainy season, and also to avoid branching and deformation of the tubers after Chinese yam planting.

After the trench is filled and leveled, mix the remaining soil with fully decomposed high-quality barnyard manure at a soil-to-manure ratio of 2:1, and build soil ridges 0.5 m wide and 0.4 m high where the trench was dug to prevent rainwater from entering the trench and causing collapse. Generally, apply 10000 kg of fully decomposed high-quality barnyard manure and chicken manure, 150 kg of cake fertilizer, 50 kg of superphosphate, and 200 kg of plant ash per 667 sq m. The fertilization method is to apply the fertilizer evenly between the two ridges, turn it into the soil with a shovel, tread it firm with the feet and level it, then according to the terrain and landforms, build a complete field water system to facilitate drainage and waterlogging reduction or irrigation in the dry season.

4. Treatment of Chinese yam seed

1. Select the upper section of tubers with bright color and a diameter of more than 3 cm reserved before winter, or the upper-end bud as seed tubers, with a seed tuber length of 35-40 cm. They are required to have no mildew spots, no disease spots, and no rot. In terms of seed quality, Chinese yam slips are better than finished Chinese yam, and the yield difference is relatively large.

2. In mid-March, take the upper tuber sections and cut them into segments, each 15-20 cm long, then immediately dip the cut surfaces in quicklime powder and sun-dry them for 3-5 sunny days.

3. Place the cut Chinese yam outdoors and expose it to sunlight for 5-7 days to increase the bound water content of the seeds and promote callus formation. Fourth is “soaking”: before planting, soak the seed tubers in a 300-fold solution of 40% carbendazim suspension concentrate for 15 minutes, remove them, let them dry, and then plant.

5. Mulching with film

Chinese yam is suitable for planting in late March and early April. The plant spacing is 0.23-0.25 m, and the planting density per 667 sq m is 2600-2900 plants. The method of planting seed tubers is to open a trench on the soil ridge, 10 cm deep, place the seed tubers or buds flat in the trench, then cover with 5 cm of soil, tread firm and level, and cover with plastic film. According to surveys from multiple locations, film mulching can lead to emergence about 15 days earlier, with neat emergence and rapid stem and leaf growth, and the full-trellis period is advanced by 33 days.

6. Fertilization and watering methods for Chinese yam

After Chinese yam emerges, appropriate seedling-promoting fertilizer should be applied according to seedling conditions. Generally, 20 kg of ammonium bicarbonate and 15 kg of superphosphate can be applied in holes per 667 sq m. In mid-June, when the vines and tubers enter the growth period and the underground tubers begin to expand rapidly, generally 25 kg of ammonium bicarbonate, 20 kg of superphosphate, and 50 kg of plant ash should be applied per 667 sq m. In mid-August, carry out pest and disease control according to plant growth and appearance, and spray a 1% urea and 0.25% potassium dihydrogen phosphate solution on the leaves once every 10 days for 3-4 consecutive times to prevent premature aging of the plants.

For the watering management of Chinese yam, attention should be paid to keeping the soil moist during the peak tuber growth period, and not irrigating unless there is drought.