Potato planting technology and management methods

Potatoes, also known as potatoes, are a versatile crop that can be cooked as a vegetable or eaten as a grain. They are similar to sweet potatoes in that they grow underground. Potatoes have a relatively short growth cycle and high yield, which makes them widely planted in many regions of China. However, farmers may face several challenges during the cultivation process that may negatively affect potato yields. In fact, growing potatoes is not difficult. The key is to master the correct method. With the right technology, your potato crop can also achieve high-quality and abundant yields.

1. Determine the planting time

Potatoes prefer cool climates and cannot tolerate heat. The germination and growth of potatoes require certain temperature conditions: seeds begin to germinate at temperatures above 6-8°C. The soil temperature of 13-18°C is most suitable for seed germination. Above-ground stems and leaves grow most vigorously at temperatures between 16-22°C. Underground tubers expand fastest in an environment of 16-28°C.

If the soil temperature is below 5-10°C for a long time after sowing, the seeds may rot, fail to germinate or seedling. If the temperature is below 10°C or above 25°C for a long time during the growing season, the growth of stems and leaves will be hindered. If the temperature during the underground tuber expansion period is above 20°C for a long time, the expansion rate will slow down, and the growth may stop above 30°C.

The planting time of potatoes is generally concentrated in spring from February to May. In areas with warm climates, seeds can be sown in February and March, while in cold areas such as the Northeast, it will have to wait until April and May. The sowing time should be based on the local spring warming conditions, usually when the soil temperature is stable at above 6-8°C and the air temperature is stable at above 13-15°C.

2. Choose a suitable planting site

Potatoes have shallow roots and have high requirements for soil environment. Ideal soil should be fertile, loose, well-drained, and have the ability to retain water and fertilizer. Such soil conditions are conducive to the growth of potato plants and the enlargement of tubers, thereby improving yield and quality.

When choosing a planting site, priority should be given to loam or sandy loam with deep, loose, well-drained soil. The soil pH value should be within the slightly acidic range of 5.5-6.0, which is conducive to the rapid germination, uniform emergence and root development of potatoes, so that the harvested potatoes are large, have clean skin and good taste.

Planting potatoes should be avoided in soils that are highly acidic or alkaline, poor in fertility, heavy in clay, sandy or prone to waterlogging, as these conditions will cause poor growth of potatoes and affect yield and quality.

When planting potatoes in sandy soil, since water and nutrients are easily lost, more well-rotted farmyard manure and chemical fertilizers need to be applied, and irrigation management needs to be strengthened. When planting in heavy clay soil, high ridge planting should be adopted, more organic fertilizer should be applied to improve soil permeability, and attention should be paid to drainage and inter-tillage loosening of the soil. Potatoes are susceptible to pests and diseases in soils that are too acidic or alkaline, so they should be avoided.

After selecting the planting site, it is recommended to deep plow the soil 15-20 days before sowing, to a depth of about 25-30 cm, and dry the soil to create a good growth environment for potatoes. Through these meticulous planting management measures, the potato planting results can be effectively improved.

3. Choose high-quality potato seeds

The quality of seeds used when planting potatoes directly affects the germination time and uniformity of emergence. Poor quality seed potatoes may result in poor germination and emergence.

When choosing potato seeds, the following factors should be considered: Choose appropriate varieties based on the planting season, local climate, planting time, management methods and market demand. For example, cold-resistant varieties should be selected for early spring sowing, and varieties with high starch content should be selected for starch processing.

Choose varieties with strong adaptability, good disease resistance, strong stress resistance and high germination rate. Choose potato seeds that are plump in shape, smooth in skin, uniform in size, and free of disease spots, insect pests, and mildew. Avoid choosing potato seeds that are shriveled, moldy, cracked, deformed, or have dull skin, black navels, necrotic eyes, as well as those that have experienced frost damage, flooding, disease, or variety degeneration.

4. Drying and sterilization before sowing

The purpose of drying potato seeds before sowing is to enhance the activity of potato seeds, promote rapid germination and uniform emergence. Reduce the incidence of diseases and kill the pathogens remaining on the surface of potato seeds.

Seed drying operation: Take out the potato seeds 10 to 15 days before sowing. Choose a sunny day and spread the potato seeds on a cardboard box, straw mat or fertilizer bag, about 10 to 15 cm thick. Spread the seeds out for drying in the morning and pile them up in the afternoon. Turn them over 2 to 3 times during the drying process to ensure even drying. Dry in the sun for 2 to 3 days.

5. Effect of potato seed size on emergence and yield

The potato seeds you purchase or prepare yourself may vary in size. The size of potato seeds will affect germination speed, seedling quality and later growth, which in turn affects yield. Potato seeds that are too small lack nutrients and may cause weak seedling growth; potato seeds that are too large have sufficient nutrients but will increase the amount of seeds needed.

The ideal weight of potato seeds is 30 to 40 grams, which can ensure growth and yield while saving costs. Cut the pieces 1 to 2 days before sowing to avoid water loss. For larger potato seeds, they should be cut into pieces before sowing. When cutting, ensure that each small potato piece weighs 30 to 40 grams, has at least one strong sprout, and the maximum weight does not exceed 40 to 50 grams.

6. Germination Method

The first germination method: fine sand germination

Select and dry the potato seeds, and bury them in the moist fine sand prepared in advance. During the germination period, maintain the sandy soil constantly moist and at a temperature of 16-20°C. After about a week, when the sprouts of most potato seeds reach 0.6-0.8 cm in length, they can be cut into pieces and sown.

The second germination method: stratification germination

Spread a layer of moist sand about 10 cm thick on the indoor floor. The potato seeds are stacked one layer at a time and then another layer at a time with wet sand to form a layered structure. Keep the germination environment temperature at 16-20°C and humidity at 80-85%. After about a week, when most of the young shoots on the potato seeds reach 0.6-0.8 cm in length, they can be cut into pieces and sown.

Precautions during germination: It should not be too long or too short. Too long a time may cause the young shoots to be too fat and easily break during sowing; too short a time may cause the young shoots to be thin and weak, affecting the germination time. Excessively high temperature and humidity may cause potato seeds to rot or young shoots to be weak. Too low temperature and humidity may prolong the growth time of young sprouts and delay the sowing period.

Precautions when cutting: Use high-concentration alcohol or potassium permanganate to disinfect cutting tools to prevent the spread of diseases. Remove the tail buds, side buds and small weak buds on the potato tubers to promote uniform and strong seedlings.

7. Planting density and depth

Sowing density: For potatoes sown in large and small rows, the recommended density is 70-80 cm for large rows, 20-25 cm for small rows, and 30-35 cm between plants. For sowing in equal row spacing mode, it is recommended that the row spacing and plant spacing be controlled at 60-70 cm and 20-25 cm. The suitable number of potato seedlings per acre is about 4000-5000 plants. Soil conditions with excellent fertility and water, early-maturing varieties or varieties with low plant shapes can be planted moderately densely; on the contrary, soil conditions with poor fertility and water, late-maturing varieties or varieties with tall plant shapes should be planted moderately sparsely.

Sowing depth: The recommended depth for potato sowing is 10-12 cm, and covered with 2-3 cm of thin soil after sowing. For spring sowing, early-maturing varieties or areas with heavy rainfall, shallow sowing should be done to facilitate germination. For autumn sowing, late-maturing varieties or areas with drought and little rain, it is advisable to sow deeply to reduce the impact of drought on emergence.

Note: The sowing density needs to be considered comprehensively based on soil fertility, variety characteristics and climatic conditions to achieve the best photosynthesis and growth effects. The sowing depth should take into account the soil's drainage capacity and water retention capacity to avoid uneven germination or disease problems caused by sowing too deep or too shallow.

8. Sowing Method

Compared with traditional open-field flat-bed sowing, potato sowing using ridge-forming and film-covered planting methods has many advantages: ridge-forming and film-covered planting methods help increase yields because potatoes germinate and emerge faster in this method. The seedlings grow more vigorously, mature earlier, and can be put on the market earlier. The potatoes expand faster, become larger in size, have cleaner and smoother skin, and have improved taste and quality.

Before sowing potatoes, you should first water them thoroughly to ensure that the water completely penetrates the soil and provide good germination conditions for the potatoes.

Sowing seeds with the sprouts facing upwards: This method helps the potato roots penetrate deep into the soil, enhances drought resistance, and promotes early growth and larger potato sizes. However, this method may result in a slightly later germination time and a slightly reduced number of potatoes.

Sowing seeds with sprouts downwards: This method can make the potatoes emerge slightly earlier and develop thicker and shorter roots, thereby increasing the number of potatoes. However, the disadvantage of this method is that although the number of potatoes increases, the size of each potato may be slightly smaller.

9. Break the film and release the seedlings in time

For potatoes grown using film mulching technology, when the seedlings emerge from the soil and grow 1 to 2 true leaves, or when the seedlings push up the film, the film must be broken and the seedlings released in time to avoid damage to the seedlings from high temperatures.

Breaking the film and releasing the seedlings should be done at a time when the impact on the seedlings is minimal: on sunny days, choose before 10 am or after 4 pm. During these two periods, the light is weak and the temperature is moderate, which helps reduce the light and temperature shock to the seedlings. If it is cloudy, you can break the film and release the seedlings at any time of the day, because the light and temperature changes on cloudy days are smaller, and the impact on the seedlings is relatively small.

Operation precautions: Be careful when breaking the film to avoid damaging the seedlings. After breaking the film, closely observe the growth of the seedlings to ensure that they adapt to the external environment and grow healthily.

10. Fertilization management

Application of base fertilizer: The base fertilizer before potato planting is mainly organic fertilizer or farmyard manure, which is applied in combination with land preparation to provide a comprehensive nutrient basis. It is recommended to apply 3,000 to 5,000 kilograms of decomposed farmyard manure per mu, combined with 30 to 40 kilograms of sulfur-based compound fertilizer with a nitrogen, phosphorus and potassium ratio of 12-15-18, and 20 to 25 kilograms of superphosphate.

Top dressing during the seedling stage: After emergence, top dressing mainly with nitrogen fertilizer is used to promote the growth of seedlings. Potassium dihydrogen phosphate, brassinolide and magnesium sulfate can be used for foliar spraying to supplement the necessary nutrients.

Top dressing during the budding stage: After budding, top dressing mainly with potassium fertilizer will promote the formation and expansion of potato tubers. Apply 15 to 20 kg of sulfur-based compound fertilizer with a nitrogen, phosphorus and potassium ratio of 13-10-20 per mu, and cover the soil with topdressing. At the same time, spray potassium dihydrogen phosphate, chelated calcium and boron fertilizer on the leaves to supplement trace elements.

Top dressing from the peak flowering period to the end of flowering: From the peak flowering period to the end of flowering, use 5 kg of macro-element water-soluble fertilizer with a nitrogen, phosphorus and potassium ratio of 18-6-35 per mu and apply it with water. After the flowers fade, spray potassium dihydrogen phosphate, chelated iron, boron fertilizer and brassinolide on the leaves to enhance the plant's disease resistance and promote tuber growth.

Top dressing during the swelling period: During the swelling period of underground tubers, it is possible to flexibly decide whether to top dress again based on the growth of potatoes. If necessary, it is recommended to use potassium sulfate fertilizer, applying 10 to 15 kg per mu.

Fertilization adjustment for film-mulched planting: For potatoes planted with film, if it is not possible to cover the soil and apply topdressing, you can use water flushing or drip irrigation to ensure the effective supply of nutrients.

11. Watering management

1. Water control from sowing to budding:

If the bottom water has been thoroughly applied before sowing, as long as the soil is not dry, potatoes do not need frequent and large-scale watering from seedling emergence to budding and flowering. Proper water control and seedling squatting are beneficial to high potato yield. If you find that some seedlings are wilting at noon, you can spray a small amount of water in the morning or evening or use dilute manure water to gently increase the water supply.

2. Water supply after flowering

After the potatoes bloom, the underground tubers begin to swell, and this is when you should start watering them. Depending on weather and soil moisture, water lightly every 7 to 10 days until about 10 days before harvest. Doing so can meet the water demand during the rapid expansion period of the tubers. At the same time, moderate watering before harvest can help increase the weight and quality of the potatoes, and prevent cracking or rotten potatoes caused by excessive water absorption.

3. Maintain soil moisture during the growing season

During potato growth, it is ideal to maintain soil moisture at 70-75%. Especially during the period of underground tuber expansion, avoid drastic changes in soil moisture to prevent the potatoes from cracking or rotting.

12. Multiple soil cultivation to promote high yield

Potato soiling usually needs to be done in three steps:

The first soiling: This is done after the seedlings have all grown up. The soiling should be deep to promote root development.

Second soiling: From the plant growth stage to the budding stage, the soil should be added shallowly to avoid damaging the plants.

The third soiling: When the underground rhizomes begin to swell, the soiling should be done lightly, which is called "light scrape". The purpose of soiling is to prevent the potato underground rhizomes from exposing the ground. If they are found to be exposed, they should be covered with soil in time.

13. Timely control of vigorous growth during the budding period

Excessive growth of potato stems and leaves will affect the development and yield of underground tubers. In seasons with heavy rainfall and when plants tend to grow vigorously, timely measures should be taken to control their vigorous growth according to the growth of the plants.

The best time to control vigorous growth: the critical period of growth transformation when potatoes begin to show buds. The plant height reaches about 40 cm. When the stems and leaves begin to cover the ridges or buds appear sporadically.

Drug control of growth: plant growth regulators such as paclobutrazol, chlormequat, and mepiquat can be used for spraying. 10 to 15 days after the first spraying, if the plant is still growing vigorously, spray again. Usually two sprayings can effectively control vigorous growth.

Precautions for the use of potassium fertilizer: Potatoes are potassium-loving crops, and adding appropriate amounts of potassium fertilizer can help to achieve high yields and good returns. However, the choice of potash fertilizer is particular: potassium sulfate should be used and potassium chloride should be avoided. The chloride ions in potassium chloride may inhibit the synthesis and accumulation of starch in potato underground rhizomes, affecting the quality and taste of potatoes.

The above is an introduction to the key points of potato planting technology and management skills. When planting potatoes, you can fully consider these key points based on actual conditions to ensure a good harvest.