What are the key points to note for spring potato cultivation?
Potato (scientific name: Solanum tuberosum, English: potato), of the nightshade family (Solanaceae) and genus Solanum, is an annual herbaceous plant, also known as didan, yangyu, tudou, and other names. The earliest artificial cultivation sites of the potato can be traced back to around 8000 to 5000 BC in the southern region of Peru. The potato grows 15-80 cm tall, hairless or sparsely pubescent. The stem is divided into two parts: the aboveground stem and the underground stem. Potato is one of China's five major staple foods; it has high nutritional value, strong adaptability, and high yield, and is the world's third most important food crop, after wheat and corn. Potato propagates by tubers and can be used as medicine; it is neutral in nature and sweet in taste, and can treat stomach pain, hypochondriac pain, carbuncles and swellings, and other diseases. As a food, its storage period should not be too long, and it must be stored at low temperature, dry, and sealed. (Note: the young sprouts are slightly toxic.) There is evidence that the vitamin C content of potato is about 4 times that of apple.
Morphological characteristics of potato
Tuber morphology: herbaceous. The fruit is tuber-shaped, oblate, or 15-80 cm tall, spherical, hairless or sparsely pubescent. The stem is divided into two parts: the aboveground stem and the underground stem. Oblong, about 3-10 cm in diameter, with white, light red, or purple skin. The skin color of the tuber is white, yellow, pink, red, purple, and black, and the flesh is white, light yellow, yellow, black, blue, purple, and black-purple.
Plant morphology: fibrous root system. The aboveground stem is rhombic and hairy. The primary leaves are simple and entire. As the plant grows, it gradually forms odd, unequal pinnately compound leaves. The leaflets are often alternately large and small, 10-20 cm long; the petiole is about 2.5-5 cm long; the leaflets are 6-8 pairs, ovate to oblong, the largest up to 6 cm long and 3.2 cm wide, the smallest less than 1 cm in both length and width, with a pointed tip, a slightly unequal base, entire margins, both surfaces covered with white appressed hairs, 6-7 lateral veins on each side, the tip slightly curved, and the petiolule about 1-8 mm long. The corymb is terminal, later lateral, with white or blue-purple flowers; the calyx is campanulate, about 1 cm in diameter, sparsely pubescent outside, 5-lobed, the lobes lanceolate with a long acuminate tip; the corolla is rotate, about 2.5-3 cm in diameter, the corolla tube hidden within the calyx, about 2 mm long, the limb about 1.5 cm long, with 5 triangular lobes about 5 mm long; the stamens are about 6 mm long, and the anther is 5 times the length of the filament; the ovary is ovate, hairless, the style about 8 mm long, and the stigma capitate.
Fruit morphology: potato is spherical, smooth, brown or purple-brown, about 1.5 cm in diameter. Seeds are kidney-shaped and yellow. The flowering period is in summer.
Key points to note for spring potato cultivation
Spring is the time to cultivate potato, and it can be marketed in May, which improves the planting benefits of potato, but there are still many things to note when cultivating potato in spring. Let us learn about them together below.
Spring potato tubers can sprout when the ground temperature at a depth of 10 cm reaches 7-8°C, grow vigorously at 10-12°C, and quickly emerge from the soil. This is the temperature indicator for sowing in various places.
Potato has wide adaptability; generally choose fields with loose texture and easy irrigation and drainage, and deep plow 20-25 cm; make high beds 95 cm wide, with furrows 25 cm wide and 25 cm deep. Before sowing, apply enough base fertilizer at one time, and apply the fertilizer in the center of the bed while preparing the land. Apply 1500-2000 kg of decomposed organic fertilizer, 15 kg of ternary compound fertilizer, and 15 kg of potassium sulfate per mu.
For spring potato, choose extra-early-maturing or early-maturing virus-free varieties free of disease and injury, such as Zhongshu No. 2, Zaodabai (vegetable type), Favorita, Zhengshu No. 5 (export type), Huangmazi (high-starch type), Zihuabai, Atlantic (processing type), etc. These varieties are harvested 60-80 days after full emergence, with a yield of 1500-2000 kg per mu. The seed tuber size is preferably 50-100 g. 10-15 days before sowing, if the seed tubers have not yet broken dormancy, dormancy must be broken. There are two methods:
First, cut the seed tuber lengthwise from the top into several pieces, each with 1-2 buds, and the cut should be close to the buds.
Second, soak the seeds in a gibberellin solution. Seed soaking is divided into whole-tuber soaking and cut-piece soaking. For whole-tuber soaking, use a 10-20 mg/L gibberellin solution for 30 minutes; for cut-piece soaking, use a 5-10 mg/L gibberellin solution for 5-10 minutes. Preparation of the gibberellin solution: first dissolve gibberellin with a small amount of alcohol or liquor, then add water; 1 g gibberellin to 100 kg water makes a 10 mg/L gibberellin solution. Before soaking seeds in the gibberellin solution, wash the starch from the cut surfaces with clean water; after soaking, remove the tubers and place them in a cool place to air-dry for 4-8 hours. Never expose them to the sun, to avoid rotting of the seed. The gibberellin solution can be reused for soaking seeds 4-5 times, but the concentration must not be too high, to avoid excessive vegetative growth at the seedling stage. For sprouting, a cold frame, greenhouse, or plastic tunnel can all be used. Spread clean wet sand on the ground (it should form a ball when squeezed by hand and scatter when released), about 10 cm thick, with a bed width of 1 m. After the cut seed tuber pieces are washed and dried, spread them evenly on the seedbed (do not let them overlap), with the buds facing up, then cover the tubers with sandy soil, place 2-3 layers in this way, and finally pat the bed surface firm. During sprouting, plastic film can be used to keep warm, maintaining the temperature at 25-28°C, and keeping the sandy soil moist, with the surface sand not turning white. When the sprouts are 1-2 cm long, they can be transplanted.
Generally, wide-narrow row planting is used, with a large row spacing of 80 cm, a small row spacing of 35-45 cm, a hole spacing of 18-20 cm, and a sowing depth of 7-9 cm, planting 5000-6000 plants per mu. The soil must be kept moist when transplanting. Single-film or plastic-film plus small-arch-film “double-film” mulching cultivation can be used, which can increase the rate of large and medium tubers by 10%-30%, has a significant yield-increasing effect, and can bring the crop to market 10-20 days earlier.
Generally, do not water before emergence. After rain, if the soil is compacted, loosen the soil in time to aerate it. After full emergence, apply a seedling-promoting fertilizer, using 5 kg of urea per mu diluted in water or applying decomposed human manure and urine. At the tuber initiation stage, combine with shallow intertillage and light hilling; at the tuber bulking stage, combine with clearing the furrows and perform deep intertillage and heavy hilling. Especially for the Favorita variety, straw mulching must be used to prevent greening. At the same time, prevent water accumulation in the field, otherwise the tubers are prone to rot.
If spring potato is given too much nitrogen fertilizer, it is prone to excessive vegetative growth. At the bud stage, spray 15 g of 15% paclobutrazol wettable powder diluted in 45 kg of water to control aboveground excessive growth and help set more tubers. At the full flowering stage, spray 50 kg of 0.2%-0.3% potassium dihydrogen phosphate solution per mu to promote tuber bulking.
The main disease of potato is late blight, which occurs severely when there is excessive rain or around the flowering period. Spray early with 25% ridomil or metalaxyl 800-fold solution. The main pests include aphids, white grubs, and others. In the early stage of aphid occurrence, spraying 2.5% deltamethrin diluted 2500 times with water has a good effect. To control white grubs, dissolve 0.5 kg of 90% crystal trichlorfon in water, then spray it onto 35 kg of fine soil, mix well to make poisonous soil, and scatter it in the furrows. Around early May, spring potato can be harvested at the late tuber bulking stage.