Detailed Explanation of Cultivation Techniques and Management Key Points for Air Potato
Foot potato is named for its flattened underground tubers, which resemble the shape of a foot sole. It has strong adaptability and a wide planting range, making it very suitable for cultivation. So what are the cultivation techniques for foot potato?
I. Propagation Methods
1. Seed tuber cutting propagation method: At harvest time the previous year, select tubers that are robust in growth, relatively slender, have few fibrous roots, smooth skin, and no wounds. Air-dry them for 1-2 days, then store them in a cellar. Take them out before planting the following year, cut each seed tuber evenly lengthwise into two long pieces, then cut crosswise into small pieces about 5-10 cm long and about 100-120 g each. Be careful to ensure each small tuber piece has a bud eye. Then coat the cut surface of each piece thoroughly with plant ash, place them in the sun to dry for 1-2 hours, then keep them indoors to air-dry for 1-3 days. Wait until the cut surfaces have healed before sowing. This can prevent the cut surfaces from rotting and promote uniform sprouting. This method produces early seedlings, fast growth, and high yield, but the propagation coefficient is low and the amount of seed used is relatively large. If the expansion area is relatively large, you can collect tuber crowns (tops) as seed during normal consumption. That is, when consuming them in large quantities, leave the tuber crowns at 5 cm long, coat the cut surfaces with plant ash, air-dry them, and store them in a cellar as seed. After propagating with the above methods for 2-3 years, the variety tends to degenerate, which affects yield. In production, it is often combined with the aerial tuber propagation method.
2. Aerial tuber propagation method: Aerial tubers are aerial tubers borne in the leaf axils of the vines. This propagation method requires appropriately earlier transplanting, extending the growth period as much as possible to increase yield. The yield harvested by this method may be relatively lower, but it can improve the variety. The specific method is: before the aerial tubers naturally fall off, harvest larger ones (egg-sized) with few fibrous roots and smooth surfaces, and store them in sand indoors over winter. The following year, when the local temperature stabilizes above 10°C, take out the aerial tubers and place them in the sun for 2-3 hours, then put them in an insulated shed to promote sprouting. Keep the shed temperature at about 25°C. When the sprouts reach 3-5 cm, plant them conventionally.
II. Planting
From mid-to-late April to early May, use the two-row-per-bed method. Open two 8 cm planting furrows on each bed, then scatter lime into the planting furrows to control underground pests. Place the seed tubers at a plant spacing of 33-40 cm, taking care to place the cut surface of the tuber pieces facing downward and the skin surface facing east (the direction of the rising sun). Then cover with soil and form ridges about 10 cm high. Planting without sprouting promotion results in slower emergence, but the roots develop first and then the sprouts, resulting in a well-developed root system and robust growth.
III. Management
1. Set up trellises and guide vines, thin seedlings and remove sprouts. When the seedlings grow to 25-30 cm, use 2 m long small miscellaneous wood stakes inserted upright to form independent trellises, or use small mountain bamboo to form A-shaped trellises, and help the stems and vines climb up. Keep only 1 strong seedling per hill and remove all the rest. If the stems and vines grow too vigorously and produce too many axillary buds, remove them. In July, for the aerial tuber flower buds growing from the leaf axils, except for retaining robust ones for seed, promptly remove the rest to reduce nutrient consumption and favor tuber enlargement.
2. Intertillage and hilling. Foot potato has many roots, and they are mostly distributed on the soil surface. To avoid damaging the roots, only one intertillage is needed during the seedling stage, and camellia seed hulls are scattered between the hills. Camellia seed hulls are a very good fertilizer and also help prevent weeds, loosen the soil, and control insects. When the stems and vines grow to about 1.2 m, hill up once in combination with fertilization, then cover the entire bed with thatch. This can both prevent weeds from growing thickly and eliminate the need for intertillage, and also regulate temperature and humidity.
3. Fertilizer and water management. Apply topdressing 3-4 times during the growth period. Seedling-promoting fertilizer: In combination with intertillage, dig 6-10 cm fertilizer furrows between the rows, apply 5-10 kg of urea per 667 sq m, cover with soil, and cover the spaces between hills with camellia seed hulls. Seedling-strengthening fertilizer: In combination with hilling, apply 10-20 kg of calcium magnesium phosphate fertilizer per 667 sq m and an appropriate amount of plant ash and farmyard manure. Apply one heavy fertilizer each at the flower bud stage and the mid-tuber enlargement stage, applying 500-1000 kg of human urine per 667 sq m. Human urine significantly promotes tuber enlargement and plays a key role in yield formation. Do not apply human feces or pig and cattle pen manure as topdressing, because manure fertilizer easily causes the stems, vines, and tuber skin color to turn black, leading to disease. Foot potato is relatively drought-tolerant and has low water requirements. If drought occurs from July to August, watering 1-2 times appropriately is sufficient.
IV. Pest and Disease Control
Foot potato has relatively few pests and diseases. For small-scale planting, pesticides are generally rarely used. For larger-scale planting, agricultural control is also the main approach, with pesticides as a supplement, mainly selecting some high-efficiency, low-toxicity, low-residue pesticides. The main diseases include anthracnose and rust, which can be controlled with carbendazim, thiophanate-methyl, triadimefon, and others. Pests include sawflies, cutworms, white grubs, and other underground pests, which can be controlled by drenching the roots with 800 times diluted trichlorfon solution. Generally, no pesticides are used one month before harvest.