At present, potato is the most important food crop used as human staple food in the world except grain, mainly eating its underground tubers. Widely planted all over the world, thousands of varieties have been cultivated. Strong adaptability to soil, but it requires a cool, cold and dry climate. Although it can grow in hot and humid areas, the varieties will degenerate after one generation, so it is necessary to introduce new potato varieties from cold areas frequently.
The main potato producers in the world are the former Soviet Union, Poland, China and the United States. The main potato producing areas in China are southwest mountainous area, northwest, Inner Mongolia and northeast. Among them, the southwest mountainous area has the largest planting area, accounting for about 1/3 of the national total area.
Dingxi, Gansu is rich in potatoes, often called "potato" by local people, and it is one of the local staple foods. At the beginning of April, 2006, the local government of Dingxi, Gansu Province applied to the Specialty Economic Committee of China Agricultural Association, and named the county "China Potato Town". On April 6th, a group of five people, including Sun, deputy director of the Organizing Committee for the Promotion of China Specialty Hometown, president of China Specialty Newspaper, vice president and secretary general of China Agricultural Association, visited Dingxi County, reported it to the Specialty Economic Committee of China Agricultural Association for approval, and agreed to name Dingxi as "the hometown of potatoes in China". Tengzhou, Shandong Province is known as the "granary in southern Shandong", with 323 varieties of crops and 0/45 varieties of livestock. It is listed as a commodity grain base and a high-quality vegetable base by the state and Shandong Province, and it is the largest vegetable distribution center and "green goat base" in China. Heilongjiang Province is the largest potato planting base in China. Common cultivated potatoes are propagated and grown by tubers, and their morphology varies from variety to variety. The plant height is about 50 ~ 80 cm. The stem is divided into two parts: aboveground stem and underground stem. Tubers are round, ovoid or rectangular. The color of potato skin is white, yellow, pink, red or purple; Potato meat is white, light yellow or yellow. Plants grown from seeds form slender main roots and branched lateral roots; Tuber-propagated plants have no main roots, but only fibrous roots. Primary leaves are simple and intact. With the growth of the plant, pinnate compound leaves gradually formed. Cymes are terminal, with white, light blue, purple and red. Berries. Due to different geographical and climatic conditions, potato cultivation techniques are different around the world. Tubers are mainly used for asexual reproduction. In order to avoid virus (spindle tuber, X and S mosaic virus) infection and knife ring rot, healthy seed potatoes with a diameter of 3 ~ 3.5 cm should be selected for whole potato sowing. Potato is the most susceptible to disease, and fungal diseases include late blight, scab and early blight. Bacterial diseases include ring rot and bacterial wilt. Viral diseases include mosaic, leaf curl, viroid and mycoplasma. Pests include tuber moths, nematodes, cutworms and grubs. Most cultivated varieties are selected through cross breeding. In view of the shortage of common cultivated potato varieties, in recent years, special attention has been paid to the comprehensive genome of potato-related cultivars, including common cultivars and diploid cultivars, in order to facilitate the breeding of new varieties with high yield, high resistance, high starch and high protein content.
The main breeding approaches are as follows: ① The diploid hybrids producing 2n gametes are crossed with common cultivated species. (2) The new cultivated varieties are crossed with the common cultivated varieties. Potatoes have high nutritional value and medicinal value. Generally, fresh potatoes contain starch 9-20%, protein 1.5-2.3%, fat 0.1-1%and crude fiber 0.6-0.8%. The nutritional components in 100g potato are: heat 66 ~ 1 13j, calcium1~ 60mg, phosphorus 15 ~ 68mg, iron 0.4~4.8mg and thiamine. In addition, potato tubers also contain carotene and ascorbic acid that cereals do not have. From the nutritional point of view, it has more advantages than rice and flour, and can supply a lot of heat energy to the human body, so it can be called "perfect food". People only rely on potatoes and whole milk to maintain their lives and health. Because the nutritional components of potatoes are very comprehensive and the nutritional structure is reasonable, but the contents of protein, calcium and vitamin A are slightly lower; And this is just a supplement to whole milk. Potato tuber is rich in water, low in fat and low in calories per unit volume. It contains 10 times of vitamin C, 4 times of B vitamins and several to several times of various minerals, which makes you feel full after eating. Potatoes Fresh potatoes can be used as food or vegetables. However, fresh potato tubers are bulky and have high water content, so it is difficult to transport and store them for a long time. For this reason, countries all over the world attach great importance to the production of potato processed foods, such as French frozen fried strips, fried chips, instant whole flour, starch and various cakes and egg rolls, reaching more than 100. Fresh stems and leaves of potato can be used as feed through silage, but it contains solanine to prevent livestock poisoning. In some areas of China, potato stems and leaves are used as green manure, and their fertilizer efficiency is similar to that of Chinese milk vetch.
Potato, also known as potato, potato and yam egg, is one of the main food crops in the world. Second only to rice, wheat and corn. In recent years, China's potato planting area is about 45 million mu, ranking first in the world. Potatoes are planted in all provinces (cities) in China, especially in cold areas in the north and mountainous areas in the southwest. Sichuan is the province with the largest potato planting area, which has grown from 2 million mu in the 1950s to 4.5 million mu (including the Spring and Autumn Period, excluding Chongqing), and the yield per mu in a large area is generally around 1 1,000 kg. Potato has comprehensive nutrition, high value and long storage time, and is a good food for rural residents to improve food structure and health care. In recent years, with the development of potato processing industry and the adjustment of agricultural planting structure, the area of potato intercropping, autumn and winter planting and multiple cropping has been expanding, and potato has become an increasingly important food, vegetable, feed and processing raw material crop in Sichuan Province.
Section 1 Relationship between Potato Growth and Environmental Conditions
I. Temperature
The growth and development of potato need cooler climatic conditions, because it is native to the high mountains of the Andes in South America, with an annual average temperature of 5- 10 degrees and a maximum average temperature of about 24 degrees. The climatic conditions in the southwest mountainous area, part of the northwest and North China are close to the origin of potatoes. However, after years of artificial selection, there are different varieties of potato in early, middle and late maturity, which can be planted in various climatic conditions. But after all, potato plants and tubers have their natural characteristics in biological response to temperature, so it is very important to understand these conditions when cultivating potatoes.
1, plant response to temperature
Sowed potato tubers can grow when the soil temperature reaches 7 ~8 degrees at the depth of 10 cm below the ground, and the buds grow strong at 10 ~20 degrees, which will soon be unearthed. Early-sown potatoes often encounter late frost after emergence, and seedlings will suffer freezing damage when the temperature drops to -0.8 degrees. When the temperature dropped to -2 degrees, the seedlings were frozen and some stems and leaves died and turned black. However, after the temperature rises, new stems and leaves can be released from the nodes and continue to grow. The optimum temperature for plant growth is about 265438 0℃. At 42℃, the stem and leaf stopped growing. At-1.5, the stems were frozen, and at -3℃, all the stems and leaves died. The optimum flowering temperature is 15℃ to 17℃, and it will not bloom below 5℃ or above 38℃. When the temperature is -0.5 degrees, the flowers will suffer, and-1 degree will freeze them to death. Of course, due to the different cold resistance of varieties, the response to temperature is also different. However, after understanding the relationship between potato plant growth and temperature, it is of great significance to strengthen field management and ensure high potato yield.
2. The reaction of tuber to temperature
The optimum temperature for potato tuber growth and development is 65438 07℃ to 65438 09℃. When the temperature is lower than 2℃ and higher than 29℃, the tuber stops growing. Two abnormal phenomena of tuber growth are often encountered in production practice.
The first phenomenon is that the buds on the fast broadcast stem become tubers, also known as boring potatoes or dream potatoes. This phenomenon is due to poor storage conditions of tubers before sowing and high cellar temperature. When the cellar temperature is higher than 4 degrees, tubers begin to germinate after dormancy. The temperature of some pits is above 10 degrees, and the buds grow very long on the tuber. After the tuber is germinated and sown, the nutrients in the tuber meet low temperature when moving to the bud, and the bud has no growth conditions, so the nutrients are stored to form new small tubers. If the tuber doesn't germinate or grow at the beginning of sowing, it will grow normally after the temperature rises, so it won't bear tuber.
The second phenomenon is that tubers stop growing when they encounter high temperature for a long time. After watering and raining, the soil temperature drops, and tubers start growing again, that is, secondary growth. In this case, some nodules are like dumbbells, some are like beads, and there are many deformities. Of course, this phenomenon has a lot to do with whether the varieties are resistant to high temperature. When the varieties sensitive to high temperature encounter drought and water shortage, when the soil temperature rises, a large number of secondary tubers will appear, while the varieties sensitive to high temperature may not appear or rarely become branches on the ground, which seriously affects the yield or reduces the tuber quality. This variety should be irrigated in time to reduce the soil temperature.
Second, moisture.
Adequate water must be supplied during potato growth to obtain high yield. The relationship between potato water demand and environmental conditions is close and complicated. In particular, it has a great relationship with photosynthesis and transpiration of potato leaves, climatic conditions, soil types, soil organic matter content, types and quantities of fertilization, field management, planting varieties and so on. The results showed that potato plants consumed about 708 liters of water per 1 kg dry matter. When potatoes are planted in loam, the minimum water requirement for producing 1 kg dry matter is 666 liters, and the maximum water requirement for planting potatoes in sandy soil is 1046~ 1228 liters. Generally, the yield of tuber per mu is 2000 kg, and the water requirement per mu is about 280 tons, based on the weight of aboveground and underground parts 1: 1 and 20% of dry matter. The period of maximum water demand in potato growth is from budding to flowering, and the growth of stems and leaves reaches its peak in full bloom. Water shortage in this period will affect plant development and yield. From flowering to stem and leaf stop growing, during this period, the stem grows the most, and plants need a lot of water. If the water is insufficient, it will hinder the transport of nutrients to tubers.
On the other hand, inorganic elements needed for potato growth must be dissolved in water to be completely absorbed. If the soil is short of water, no matter how many nutrients there are, plants can't use them. Similarly, the photosynthesis and respiration of plants can not be separated from water for a moment. For example, lack of water will not only affect the production and operation of nutrients, but also cause the wilting of stems and leaves and the reduction of tuber production. Therefore, keeping enough water in soil is an important condition for high yield of potato. Generally, it is advisable to keep the soil moisture at 60%-80%. If the soil moisture exceeds 80%, it will also have a negative impact on plant growth, especially if the soil moisture is too much or the water is accumulated for more than 24 hours in the later stage, and the tuber is easy to rot. A large number of tubers will rot after more than 30 hours, and all will rot after more than 42 hours. Therefore, attention should be paid to drainage and high ridge cultivation when planting potatoes in low-lying areas.
Third, soil.
Potatoes adapt to a wide range of soils, and the most suitable soil for potato growth is light loam. Because tubers grow in the soil and there is enough air, breathing can be carried out smoothly. Light loam is fertile, non-sticky and breathable, which is not only beneficial to the growth of tubers and roots, but also increases the starch content. Potatoes planted in this soil generally germinate quickly, emerge neatly, and the growing tubers have smooth skin, normal shape and are easy to harvest.
Planting potatoes in cohesive soil is most suitable for high ridge cultivation. This kind of soil has poor air permeability, and it is often rotten in the later stage because of poor drainage when planted flat or in small ridges. The soil is sticky and easy to harden, which often causes tuber growth and deformation or irregular tuber shape. However, as long as the drainage of this soil is smooth and the soil retains water and fertility, the yield of planting potatoes is often high. For the management of this kind of soil, it is very important to master the water content of intertillage, weeding and ridging. Once the soil is hardened, field management is very inconvenient, especially ridging and tuber exposure will affect the quality. The starch content of potato tubers produced in this soil is generally low.
Special attention should be paid to increasing fertilizer when planting potatoes on sandy soil. Because this kind of soil has the worst water and fertilizer conservation. Sow deeply when planting, because once the rain washes away a little sand, it is easy to expose stolons and tubers, which is not conducive to potato growth, but increases the difficulty of management. Potato planted in sandy soil has neat tubers, smooth skin, normal potato shape, high starch content and easy harvest.
Potato is a crop that likes acidic soil, and it grows normally under the condition of hydrogen ion concentration of100 ~1580 nm/L (pH 4.8 ~ 7.0). When the hydrogen ion concentration is 897.1~ 2305.2 nm/L (pH 5.64 ~ 6.05), the starch content in tuber tends to increase, but when the hydrogen ion concentration is above 15850 nm/L (below PH4.8), the color change of plant leaves becomes weak and the yield decreases. When the hydrogen ion concentration is lower than 100 nm/L (PH7.0), the yield of most alkali-tolerant varieties will be greatly reduced. The concentration of hydrogen ions in soil below15.58 nm/L (above pH 7.8) is not suitable for potato planting. Potatoes planted in this soil not only have low yield, but also cannot grow or even die after sowing.
In addition, planting potatoes in soil with high calcium content is prone to scab. Because actinomycetes are particularly active in this kind of soil, the epidermis of potato tubers is often seriously damaged. Therefore, in this case, it is necessary to choose disease-resistant varieties and apply acid fertilizers.
Fourth, fertilizer.
Fertilizer is food for crops. Water yields no crops, but more fat yields less. If there is insufficient fertilizer or hunger during the growth period, it is impossible to have high yield. Potatoes are high-yield crops and need more fertilizer. When fertilizer is sufficient, plants can reach the highest growth and the corresponding tuber yield is also the highest. Among the three elements of nitrogen, phosphorus and potassium, potato needs the most fertilizer, followed by nitrogen fertilizer and phosphorus fertilizer.
1, nitrogen fertilizer
Nitrogen fertilizer plays an important role in the elongation of potato stem and the increase of leaf area. Proper application of nitrogen fertilizer can promote the lush foliage and dark green leaves of potato, which is beneficial to photosynthesis and nutrient accumulation, and plays a great role in increasing tuber yield and protein. Although nitrogen fertilizer is an important fertilizer for the healthy growth and high yield of potatoes, excessive application will cause the plants to grow white, thus delaying the fruiting of potatoes and affecting the yield. Moreover, excessive growth of branches and leaves is also prone to diseases, which will cause greater yield loss. On the contrary, if nitrogen fertilizer is insufficient, potato plants will grow poorly, with short stems, light green or grayish green leaves, few branches, early flowering, early withering of lower leaves, and finally low yield due to weak plant growth potential. Early detection of nitrogen deficiency in plants and timely topdressing can turn low yield into high yield. Practice has proved that too much nitrogen fertilizer is more difficult to control than insufficient nitrogen fertilizer. Because nitrogen fertilizer is insufficient at seedling stage, it can be supplemented by topdressing nitrogen fertilizer, but when nitrogen fertilizer is excessive, it is difficult to achieve the effect by other methods except controlling irrigation. However, controlled irrigation often leads to wilting of stems and leaves, which affects normal growth. So pay attention to the appropriate amount of nitrogen fertilizer. If you are not sure, you would rather topdressing at seedling stage than excessive base fertilizer.
2. Phosphate fertilizer
Although phosphate fertilizer is less needed during potato growth, it is an indispensable and important fertilizer for the healthy development of plants. In particular, phosphate fertilizer can promote the development of potato root system, so it is a very important fertilizer. The seedlings filled with phosphate fertilizer develop healthily, and also have the functions of promoting early maturity, improving tuber quality and improving storage resistance.
When phosphorus fertilizer is insufficient, potato plants grow slowly, the area of short leaves is small, photosynthesis is poor and growth potential is weak. There are no special symptoms in the appearance of tubers when phosphorus is deficient, and brown rust spots often appear in the cut potato meat. With the increase of phosphorus deficiency, rust spots expand correspondingly, which seriously affects the quality of potato meat during cooking.
3. Potash fertilizer
Potassium is an important element in the growth and development of potato seedlings. Adequate potassium fertilizer, healthy plant growth, stout stems, thickened leaves, dense tissues and strong disease resistance. Potassium also plays an important role in promoting photosynthesis and starch formation. Potassium fertilizer often prolongs the maturity, but the tuber is large and the yield is high.
When potassium is deficient, the internodes of potato plants become shorter, the development is delayed and the leaves become smaller. In the later stage, bronzed spots appeared on the leaves, the leaves bent downward, the lower leaves of the plant withered early, the roots were underdeveloped, the stolons became shorter, the tubers were small, the yield was low and the quality was poor. When cooking, potato meat is often gray-black.
In addition, potatoes also need trace elements such as calcium, magnesium, sulfur, zinc, molybdenum, iron and manganese. When these elements are deficient, they can also lead to diseases and reduced production. However, these elements are not lacking in most soils, so they are usually not unnecessary.
Verb (abbreviation for verb) lighting
Potato is a light-loving crop, with long sunshine time and high light intensity during its growth.
Conducive to photosynthesis. The cultivated potato varieties are basically long-day type. When the light is sufficient, the branches and leaves flourish, grow healthily, blossom and bear fruit easily, and the tuber yield is high. Especially in the plateau and high latitudes, with strong light and large temperature difference, it is suitable for potato growth and nutrient accumulation, and generally can obtain high yield. On the contrary, in the shade or when intercropping with crops such as corn, if the distance between plants is small and the growth time is long, the corn will be shaded, while the potato with short plants has insufficient light, less nutrient accumulation, tender stems and leaves, no flowering, small tubers and low yield. Even in the case of potato monoculture, if the varieties with tall plants, high density and small spacing between plants are used, they are often crowded with each other, and the lower branches and leaves are staggered, and the ventilation and light transmission are poor, which will also affect photosynthesis and yield.
Light can obviously inhibit the growth of buds on tubers. Tubers stored in the cellar can grow long white buds after dormancy due to the high temperature in the cellar. If the germinated tuber is placed under scattered light, the bud will grow slowly even at the temperature of 15℃ ~ 18℃. Planting seed potato (taro) in the south of China and accelerating germination before sowing in the north all use this point to inhibit the excessive growth of buds. In addition, accelerating seed potato germination under scattered light is also an important yield-increasing measure.
Generally speaking, under the condition of per mu yield 1330 ~ 1650 kg, potato absorbs about 6.65 ~1.65 kg of nitrogen, 2.8 ~ 3.3 kg of phosphoric acid and 9.3 ~ 15.3 kg of potassium oxide. Although potatoes can adapt to a variety of soils, loose black soil (pH 5.5 ~ 6.0) is the most ideal. The density should not be less than 4000 plants per mu.
Experts remind: You must peel potatoes.
Note: The origin of potatoes is Lake Titicaca.