Key points of high-yield potato cultivation technology

Potatoes generally prefer cool climatic conditions and are a crop that is relatively resistant to low temperatures. During the formation and growth of its underground tubers, it requires a loose, breathable, moist and cool soil environment. The temperature range suitable for potato tuber growth is 16-18℃. When the soil surface temperature exceeds 25℃, the growth of tubers will be inhibited and stop growing. Let’s learn some key points of high-yield potato cultivation technology.

1. Land cultivation

1. Soil cultivation requirements

The tillage depth needs to reach 30-45 cm. The tillage direction should be perpendicular to the sowing direction.

2. Ridge

Water appropriately according to the soil moisture, the depth is about 10-12 mm. The specifications of the ridges are about 45 cm in width, 90 cm in spacing, and about 35 cm in height. Ridge making work should be done in advance to facilitate the increase of ground temperature.

3. Soil moisture creation

Water according to soil moisture, to a depth of 20-30 mm. Soil preparation is usually done 5-10 days before sowing. Make sure to water thoroughly to avoid soil interlayers that affect root growth.

2. Seed potato preparation

Cutting is generally done 2-3 days before sowing. Germination helps seed potatoes break dormancy, shorten emergence time and promote growth. Usually 5-7 days before the seed potatoes are shipped out of the warehouse, the temperature is raised to 15-20℃ and the air humidity is maintained at 50%.

Small potatoes weighing less than 50 grams can be sown directly; potatoes weighing 51-100 grams can be cut in half lengthwise; potatoes weighing 100-150 grams can be cut into three pieces using the longitudinal oblique cutting method; potatoes weighing more than 150 grams can be cut into several three-dimensional triangular small pieces according to the number of buds, and ensure that each piece has more than 2 healthy buds. When cutting, try to take advantage of the apical dominance, with terminal buds. Cutting should be done close to the bud eyes to facilitate rooting. The weight of a single piece is between 38-45 grams (52-44 pieces can be cut from 2 kg of seed potatoes), and each piece is guaranteed to have more than 2 eyes.

Use 75% alcohol or 0.3% potassium permanganate aqueous solution to disinfect the cutting knives , ensuring that the knives are disinfected after each cut. Each person uses two knives to disinfect alternately to prevent the spread of diseases. When you encounter diseased or rotten potatoes, eliminate them in time. When cutting diseased or rotten potatoes, you need to clean the cutting knife and disinfect it again.

After cutting, in order to promote wound healing and prevent bacterial infection, use 3% Kelu + 2% Jiatuo + 95% talcum powder to treat the seed potatoes. Every 1 kg of the mixed agent can treat 100 kg of seed potatoes. Store the cuttings at a temperature of 14-16°C, with good ventilation and a relative humidity of more than 90%, observe the growth of the young shoots, and turn the piles when necessary. If sowing cannot be done immediately, a shade net should be used to prevent direct sunlight from damaging the young shoots. When sowing in spring in the north, you need to keep warm at night.

3. Sowing

When the local temperature at a depth of 15 cm stabilizes at 10-15°C, early sowing should be carried out according to local climate data. The distance from the tuber surface to the highest point of the ridge is 18-20 cm. Keep the ridge distance at 90 cm and the sowing density is generally 4800-5000 plants per mu. When sowing, apply 45-50 kg/mu of seed fertilizer with the seeder (pay attention to the NPK ratio).

4. Water and Fertilizer Management

Potato fertilization is divided into two types: base fertilizer and top dressing. The base fertilizer includes 50% of the nitrogen fertilizer, all the phosphorus fertilizer and 50% of the potassium fertilizer required during the entire growth period, and the rest is used as top dressing.

The germination period, from sowing to seedling emergence, takes 15-30 days, and is mainly focused on tuber formation and seedling growth.

It takes 15-25 days from germination to budding. This period is mainly characterized by stem and leaf growth and root development. The elongation of runners and the differentiation of lateral branch buds and leaves are critical periods for determining the number of runners and the degree of root development. It is sensitive to water and fertilizer, and focuses on strengthening seedlings and promoting growth. Water and fertilize early, strengthen tillage and weeding to promote root development and the formation of runners, and topdressing is mainly nitrogen and phosphorus fertilizers.

It takes 20-30 days from budding to flowering. During this period, the growth of above-ground stems and leaves and the formation of underground tubers take place simultaneously, and the growth of nutritional organs such as single stems, leaves and roots shifts to the stage where the reproductive organs and nutritional organs of bud development grow simultaneously. This period is the critical point of water and fertilizer. It is the most sensitive period to environmental factors such as water, fertilizer and temperature. It is also the critical period for the number of tubers produced by a single plant. Field management should include loosening the soil, applying nitrogen and potassium fertilizers, covering the soil and watering.

It takes 15-25 days from peak flowering to stem and leaf senescence. During this period, the stem and leaf growth reaches its maximum, and the stems, leaves and tubers grow rapidly. This is the period when the most water and fertilizer are needed, accounting for 50% of the entire growth period, mainly nitrogen and potassium fertilizers.

It takes 20-30 days from the end of flowering to 2/3 withering and yellowing. During this period, the stems and leaves stop growing while the tubers continue to grow and gain weight slowly. 30%-40% of the dry matter is formed during this period. Field management must ensure that there is no lack of water, prevent excessive nitrogen fertilizer, avoid premature maturity, and prevent high temperatures from causing cracks in the potato skin, making it unstorable or causing the potatoes to turn black and rot.

At maturity, 2/3 of the plants turn yellow.

5. Pest and disease control

1. Common pests of potatoes

Underground pests: cutworms, white grubs, wireworms, sand leeches, etc.; use Lorsban 100-150 ml/mu for control.

Ground pests: aphids, dragonflies; start spraying insecticides around 25 days after emergence, and rotate regularly every 7-10 days: Saidan, Aimeile, Acta, Anlubao, Anda, etc.

2. Common potato diseases

(1) Virus diseases: mosaic, necrosis, and leaf curl

Mosaic type: The chlorophyll on the leaves is unevenly distributed, showing mottled patterns of dark green and light green or yellow and green. In severe cases, the leaves are wrinkled, the whole plant is dwarfed, and sometimes the leaf veins are transparent.

Necrotic type: Brown necrotic spots may appear on leaves, veins, petioles, branches, and stems. The spots develop and connect to form edges that turn inward, become hardened, and become leathery. In severe cases, each leaflet presents as a tubular necrotic streak. In severe cases, the entire leaf dies or wilts and falls off.

Curled leaf type: The leaf edges bend upward and become cylindrical when the disease is serious. The diseased plants are dwarfed to varying degrees. Due to the destruction of the phloem, black spots can be seen on the cross-section of the stem, which are more obvious at the base and nodes of the stem. The tuber tissue showed reticular necrotic patterns in the duct area.

Prevention and control methods: Keep seed fields away from Solanaceae vegetable fields; remove diseased plants as early as possible; practice intensive farming, high ridge cultivation, and timely soil cultivation; avoid excessive application of nitrogen fertilizers, and increase the application of phosphorus and potassium fertilizers; pay attention to inter-row cultivation and weeding; control autumn water and strictly prevent flooding. In the early stage of the disease, spray 300 times diluted Kangdufeng (0.5% mushroom proteoglycan aqueous solution) or 500 times diluted 20% Virus A wettable powder , 50 times diluted 5% Bacteria and Virus Clear Water Agent, 1000 times diluted 1.5% Plant Disease Eliminator K Emulsion, 500-700 times diluted 15% Virus Bike wettable powder.

(2) Late blight: mainly attacks potato leaves, stems and tubers.

When leaves are infected, water-soaked green-brown spots first appear on the tip or edge of the leaf, surrounded by light green halos. When the humidity is high, the spots expand rapidly, turn brown, and produce a circle of white mold, namely sporangiophores and sporangia, which are most obvious on the back of the leaves. When dry, the spots turn brown and withered, become brittle and easy to crack, no white mold appears, and the expansion rate slows down.

The stems or petioles become infected and brown streaks appear. In severe cases, the leaves wilt and curl, eventually causing the entire plant to rot, and the entire field will appear scorched and emit a putrid smell.

When the tubers are infected, large brown or purple-brown spots appear, which are slightly sunken. The potato flesh under the diseased skin is also brown and slowly expands to the surrounding areas or rots away.

Drug control: In the early stage of the disease, spray the drug immediately to control its expansion and spread. Spray the medicine once every 5-7 days, and spray 2-3 times in a row. Commonly used agents include 500-750 times diluted 64% alum, 500-600 times diluted 58% wettable powder, 500 times diluted 80% Dasheng wettable powder, or 500 times diluted 40% Daknin suspension.

(3) Early blight: It mainly attacks potato leaves and can also infect tubers.

The diseased spots on the leaves are dark brown, circular or nearly circular, with concentric rings, and are 3-4 mm in size. When the humidity is high, a black mold layer grows on the lesions, which are the conidiophores and conidia of the pathogen. In severe cases, the leaves dry up and fall off, leaving the fields withered and yellow.

Infected tubers produce dark brown, slightly concave, circular or nearly circular spots with distinct edges and light brown, spongy dry rot under the skin.

Drug control: In the early stage of the disease, spray 1:1:150 Bordeaux mixture, 80% Mancozeb 600-800 times solution, and 75% Benomyl 600-800 times solution. Spray once every 5-7 days depending on the disease situation, and spray 3-4 times in total for prevention and control.

(4) Ring rot: bacterial vascular disease. The aboveground part of the disease is divided into two types: dead spot type and wilting type.

The necrotic type usually first develops on the top of the compound leaves at the base of the plant. The leaf tips, leaf margins and veins are green, the mesophyll is yellow-green or gray-green, with obvious mottles, and the leaf tips dry up or curl inwards. The disease spreads upward, causing the entire plant to die.

In the early stage of the wilting type, the apical compound leaves begin to wilt, and the leaf edges curl slightly inward, as if lacking water. The disease spreads downward, and the leaves of the entire plant begin to turn green, curl inward and droop, eventually causing the plant to fall over and die.

When the tuber is cut open, the vascular bundles turn from milky yellow to dark brown, and ring-shaped or arc-shaped necrotic areas appear in the cortex, hence the name ring rot.

After storage, the tuber buds turn black and dry or burst on the surface. They do not sprout after sowing or die after sprouting or become diseased. The vascular bundles of the roots and stems of diseased plants often turn brown, and white pus sometimes overflows from the diseased vines.

Drug control: When the emergence rate reaches 95%, use 72% Kelu, 100ml of 37.5% Quancheng suspension, 20g of 72% agricultural streptomycin sulfate soluble powder and 60kg of water per mu, spray for prevention, spray once every 7-10 days, and repeat 3-5 times.

(5) Bacterial wilt

The diseased plants are slightly shrunk, with light green or pale green leaves. The lower leaves wilt first and then the whole plant droops. Recovery begins in the morning and evening. After 4-5 days, all the stems and leaves of the plant wilt and die, but remain green. The leaves do not fall off, the leaf veins turn brown, brown stripes appear on the stems, and the vascular bundles can be seen turning brown in cross-section. When the humidity is high, bacterial liquid overflows from the cut surface.

When the tuber is infected, the disease is not obvious in mild cases, but in severe cases, the navel becomes gray-brown and water-soaked. When the tuber is cut, the vascular bundle ring turns brown and white mucus overflows when squeezed, but the skin and flesh are not separated from the vascular bundle. In severe cases, the outer skin cracks and the pith rots like mud.

Drug control: Choose a fungicide with good systemic properties, such as 70% thiophanate-methyl 700 times + 50% carbendazim 600 times or 70% thiophanate-methyl 700 times + 50% carbendazim 600 times for spraying.

The above is an introduction to the key points of potato cultivation technology. The agents in the article are for reference only and are not recommended. Please combine them with the actual situation when referring to and learning from them.