The northern region mainly refers to sweet potatoes (sweet potatoes, sweet potatoes); In some places in the south, potato is a different variety.
Sweet potato: Convolvulaceae, an important cultivated species of sweet potato, also known as sweet potato, sweet potato, sweet potato, sweet potato, sweet potato, sweet potato, red soil potato. Sweet potato is native to Peru, Ecuador and Mexico in South America. Sweet potato is cultivated in11countries or regions all over the world because of its wide adaptability, strong reproduction, simple cultivation, high and stable yield, rich nutrition and wide use, among which 10 1 belongs to developing countries. The first batch of sweet potatoes in Europe was brought back by Columbus in 1492, and then introduced to Africa by Portuguese and Asia by Pacific islands. Sweet potato was first introduced to China in Wanli period of Ming Dynasty. At that time, Chen Zhenlong, an overseas Chinese in Fujian, often went to Luzon (now the Philippines) to do business, and found that the yield of sweet potatoes produced in Luzon was the highest, so he patiently learned the planting methods from local farmers. Later, after the promotion of the Chen family, sweet potatoes were widely planted all over the country. Its main origin is located in the south of 40 north latitude. At present, the total output of sweet potato ranks seventh in the world, and it is predicted that it will rise to the fifth largest grain in the world in 2 1 century. The total planting area of sweet potato in the world has been stable at about 9.4 million hectares in recent years, and the total output is about 65.438+0.3 billion tons. Among them, Asia is the most important sweet potato producing area in the world, with planting area and total output exceeding 80% and 90% of the world respectively.
Sweet potato has been planted in China for more than 400 years. According to historical records, sweet potato cultivation is widely distributed, starting from the South China Sea Islands in the south, reaching Inner Mongolia in the north, reaching Shaanxi, Longnan and Xinjiang in the northwest, extending to the south of Heilongjiang in the northeast via Liaoning and Jilin, and reaching southern Tibet and Yunnan-Guizhou Plateau in the southwest. Sichuan basin, Yellow River basin, Yangtze River basin and southeast coastal provinces are the main sweet potato producing areas in China.
At present, the total planting area of sweet potato in China is about 6.2 million hectares, and the total output is stable at more than 654.38 billion tons, accounting for 70% and 80% of the world respectively. China has become the largest producer of sweet potatoes in the world. Among the main crops in China, sweet potato ranks fourth after rice, wheat and corn.
, contains a variety of vitamins, each 100 grams contains vitamin B 10. 12 mg, vitamin B20.04 mg, vitamin C30 mg, calcium 18 mg, phosphorus 20 mg, iron 0.4 mg, nicotinic acid 0.5 mg, crude fiber 0.5 g and carbohydrate 29. 5 grams, protein 655 mg. Has the functions of harmonizing middle energizer, promoting diuresis and invigorating spleen. Traditional Chinese medicine believes that sweet potato is a kind of diet food for promoting diuresis and strengthening the spleen.
Sweet potato has the function of moistening intestines, which can reduce fat absorption. Eating sweet potato can increase satiety and reduce appetite, thus achieving the goal of losing weight.
Here are some ways to eat sweet potatoes:
1. Steamed sweet potato
Ingredients: 500 grams of raw sweet potato.
Method: Wash the sweet potato, add proper amount of water to the steamer, put the sweet potato on the drawer, cover it and steam for 40 minutes.
2. Sweet potato glutinous rice porridge
Ingredients: 200g sweet potato, 50g japonica rice.
Methods: Wash the sweet potato, cut it into irregular small pieces, wash the japonica rice, put the rice into the pot as usual and cook it into porridge, and eat it every morning and evening.
3. Dried sweet potato
Material: sweet potato 1000g.
Method: Wash the sweet potato, steam it in a pot, let it cool, cut it into thick strips with a knife, and put it on the curtain to dry. Pay attention to ventilation and keep it out of direct sunlight. It will be available in January.
4. Fried sweet potato chips
Ingredients: 200g sweet potato, a little oil.
Method: Heat the pan on the fire, apply a layer of oil, clean the sweet potato and cut it into pieces of about 1 cm, put it in the pan and fry it until it is brown, then turn it over and fry it until it is brown and the melon slices become soft.
1, black sweet potato crystal and its preparation method
2. A processing method for making stuffed cakes with sweet potatoes or potatoes.
3. The wintering cutting method of sweet potato vine in sand storage.
4. Three-dimensional interplanting cultivation method of sweet potato and Chaenomeles.
5. A processing method of sweet potato food
6. Sweet potato fresh-keeping powder and its production method
7. Processing method of sweet potato food
8. Production method of sweet potato puffed food
9. Sweet potato chips and their production methods
10, a method for preparing sweet potato food.
1 1, a method for making sweet potato noodles.
12, sweet potato series food and production technology
13. Decolorization method of colored sweet potato starch in the production of sweet potato vermicelli.
14, flavored dried sweet potato
15. Processing method of refined sweet potato vermicelli
A medicinal material named sweet potato.
Latin famous sweet potato
Textual research on the names of sweet potato, cold melon, cold potato, pueraria lobata, pueraria lobata, radish, grass melon shavings, shage and radish.
Subject source: dicotyledonous plants, drugs, leguminous plants
The tuberous root of the medicinal part of sweet potato. The seeds of this plant can also be used as medicine.
Sex and taste belong to Lu chuan's materia medica: "sweet, cool." Into the lungs and stomach.
Efficacy is mainly used for promoting fluid production and quenching thirst. Treat fever and thirst.
Usage and dosage: raw or cooked.
Substitution function of sweet potato:
In fantasy novel, sweet potato is a magical food. I am an exorcist.
Origin and spread
J.B. Edmund and others believe that sweet potato originated in Mexico and tropical America, from Colombia, Ecuador to Peru. A.von Humboldt quoted Gomorrah as saying: When Columbus visited the Queen of Spain for the first time, he presented the sweet potato brought back from the New World to the Queen. /kloc-At the beginning of the 6th century, sweet potatoes were widely planted in Spain. Spanish sailors brought sweet potatoes to Manila and Moluccas in the Philippines, and then spread them all over Asia. Sweet potato was introduced into China through various channels at the end of 16, and it was recorded in Shu Min, Agricultural Administration Complete Book in Ming Dynasty, Zheng Minquan Book in Qing Dynasty and Fuzhou Official Records. Chen Shiyuan's Biography of Golden Potato in Qing Dynasty quoted Records of Minhou: "According to sweet potato, it was planted by overseas Luzon. During the Wanli period of the Ming Dynasty, Marco Long, a Fujian native, traded his land to get rattan seedlings and planted them in China. It is worthy of drought and flood protection in Fujian. When Jin Taishou ordered Longzi to try planting, he gained a lot and could shoot half a grain. It's planted everywhere. " He also said: "It is called sweet potato because it comes from the countryside. It is planted in Gong Jin, so it is also called golden potato. " It is also reported that Chen Zhenlong's sixth Sun Zhenyuan and his son Chen Yun spread sweet potatoes in Yinzhou (Ningbo, Zhejiang), Jiaozhou, Qingzhou (Qingdao, Yidu, Shandong) and Yuzhou (Zhuxian Town, Henan) successively, and gradually spread all over Zhejiang in about 20 years after Qingganlong. The above historical facts prove that the sweet potato line was introduced into China, Fujian and Guangdong from Nanyang at the end of 16, and then spread to the Yangtze River, Yellow River Basin and Taiwan Province Province. At present, China's sweet potato planting area and total output rank first in the world.
Distribution and planting system
The main sweet potato producing areas in the world are distributed in the south of 40 north latitude. The planting area is the largest in Asia, followed by Africa and the third in America. 1985 The cultivated area of sweet potato in the world is 8.003 million hectares, and the total output is114.38 million tons.
Sweet potato is widely distributed in China, especially in Huaihai Plain, Yangtze River Basin and southeast coastal provinces. The whole country is divided into five potato areas: ① North spring potato area. Including Liaoning, Jilin, Hebei, northwestern Shaanxi and other places, the frost-free period in this area is short, the low temperature comes early, and more spring potatoes are planted. ② Spring and summer potato areas in Huanghuai Valley. It belongs to the monsoon warm temperate climate, and it is suitable for planting potatoes in spring and summer, accounting for about 40% of the country's total area. ③ Summer potato area in the Yangtze River valley. The whole Yangtze River basin except Qinghai and Northwest Sichuan Plateau. (4) South potato region in summer and autumn. North of the Tropic of Cancer and south of the Yangtze River valley, in addition to planting summer potatoes, autumn potatoes are also planted in some areas. ⑤ Southern potato region in autumn and winter. The coastal land south of the Tropic of Cancer and islands such as Taiwan Province Province belong to tropical humid climate, with high temperature in summer and small temperature difference between day and night. Mainly planting autumn and winter potatoes.
Potato planting system is different in different regions of China. The northern spring potato area is ripe once a year and often rotates with corn, soybean and potato. Spring potato is planted in winter fallow land in spring, and summer potato is planted after winter crops such as wheat, peas and rape are harvested, with three crops in two years as the main crop. Most of the sweet potatoes in the summer potato area of the Yangtze River valley are distributed in hilly areas. Summer potato is planted after wheat and beans are harvested, and double cropping system is the most common. In other summer and autumn potato and autumn and winter potato areas, early rice and autumn potato occupy a certain proportion in the rotation system of sweet potato and rice. In the two-year four-cropping system in dry land, summer and autumn potatoes each take one crop. In the area south of the Tropic of Cancer, sweet potatoes can be planted all year round, and the proportion of sweet potatoes in autumn and winter is significant. Rotation of soybean, peanut and autumn potato is implemented in dry land; Winter potato, early rice, late rice or winter potato, late seedling field and late rice are two common multiple cropping methods in rice fields.
morphological character
Sweet potato roots can be divided into fibrous roots, firewood roots and tuberous roots. Fibrous fibrous fibrous roots, with root hairs, extend deep, generally distributed in 30 cm soil layer, and the depth can exceed 100 cm, which has the function of absorbing water and nutrients. Chaigen is about 1 cm thick and 30 ~ 50 cm long. It is a deformed fleshy root that is not fully developed due to soil drought, high temperature and poor ventilation during the growth of fibrous roots, and has no use value. Root tuber is an organ for storing nutrients and an edible part. It is distributed in the soil layer with a depth of 5-25 cm. It stretches first and then thickens. Its shape, size and flesh color vary with varieties, soil and cultivation conditions, and can be divided into spindle, cylinder, sphere and block. The skin color is white, yellow, red, reddish and purple, and the flesh color can be divided into white, yellow, orange or purple halo. It has the characteristics of rooting and germination, and is an important organ for seedling raising and reproduction. The outer layer of root tuber is the epidermis containing anthocyanin, commonly known as potato skin. Several layers of cells below the epidermis are cortex, and the inside is edible stele. There are many vascular bundles in stele, as well as primary, secondary and tertiary cambium, which are constantly differentiated into phloem and xylem. At the same time, xylem differentiated into secondary cambium and tertiary cambium, and then differentiated into tertiary and tertiary ducts, sieve tubes and parenchyma cells again. Because the secondary cambium constantly differentiates a large number of parenchyma cells and is filled with starch granules, the root tuber can expand rapidly. The phloem in the central column has tubular cells containing milk, which is initially confined to the outside of the phloem. Later, because all kinds of cambium can produce new laticifer and spread all over the root tuber, the white pulp that flows out when the root tuber is cut, that is, the milk secreted by laticifer contains jasmonate.
Sweet potato stems are creeping or semi-erect, with a length of 1 ~ 7 meters, showing green, green purple or purple, brown and other colors. Stems can germinate and save energy, and grow branches and roots. Using this characteristic of strong regeneration ability, vines can be cut, planted and propagated. The leaves are inserted on the stem nodes, and the leaf order is 2/5. The leaves are heart-shaped, kidney-shaped, triangular and palm-shaped, with different depths of the whole margin or notch, and the shapes of leaves on the same plant are often different; Green to purple-green, veins green or purplish, top leaves green, brown and purple. Cymes, axillary, like morning glory, reddish or purplish red. 5 stamens, pistil 1 piece. Capsule is nearly round and bears 1 ~ 4 brown seeds. Chromosome number 2n=90.
physiological property
The growth process of sweet potato is generally divided into three stages: rooting, branching, tuber formation, vine tuber growth and tuber growth. The requirements for external environmental conditions are as follows.
Temperature prefers temperature to cold. It is suitable for planting in areas where the summer average temperature is above 22℃, the annual average temperature is above 10℃, the effective accumulated temperature in the whole growth period is above 3000℃, and the frost-free period is not less than 120 days. When raising seedlings by heating, the temperature should be kept between 65438 06 ~ 32℃. High temperature is beneficial to the germination and growth of potatoes. The suitable temperature for long seedling stage after full seedling stage is 27 ~ 30℃, and the suitable temperature for cultivating strong seedlings is 22 ~ 25℃. After planting potato seedlings, the temperature before rooting should be above 65438 08℃. When the temperature of stem and leaf is lower than 15℃, the growth of stem and leaf stagnates, and when it is lower than 6 ~ 8℃, it withers and dies after frost. The suitable temperature for root tuber formation is generally around 25℃, and the suitable temperature for root tuber expansion is between 22℃ and 24℃. In the middle and late growth period, the temperature changes from high to low, and the temperature difference between day and night is large, which is beneficial to the accumulation of nutrients and the accelerated expansion of tubers.
Rizhao sweet potato is a kind of short-day crop that likes light, and its stems and leaves use light energy for a long time with high efficiency. The longer the growth period of stems and leaves, the more nutrients the tuberous roots accumulate. Sufficient sunshine, high temperature and ground temperature and large temperature difference are beneficial to the manufacture, operation and storage of nutrients. After a certain period of short sunshine, such as 8 ~ 10 hours of illumination every day, flowering can be promoted. Prolonging the sunshine time to 12 ~ 13 hours can promote the formation of root tuber and accelerate the operation of photosynthetic products. Not tolerant to shade, such as intercropping with tall crops, it is easy to reduce production.
The water root system is developed and more drought-tolerant. The transpiration coefficient is between 300 and 500. The optimum soil water content is 60 ~ 80% of the maximum water holding capacity. When the water holding capacity is less than 50%, it will affect the early rooting and seedling growth. With the growth of branches and stems and leaves, the soil water capacity should be increased to 70 ~ 80%; When the water content is kept at 60 ~ 70% in the later stage, it is beneficial to the rapid expansion of root tuber. 400 ~ 450 mm is suitable for precipitation in growing period. There is less rainfall in the two months before harvest, and if you suffer from waterlogging during this period, the yield and quality will be affected.
The soil requires loam and sandy loam with good soil structure, 20 ~ 30 cm thick plough layer and good ventilation and drainage, which is beneficial to root system development, root tuber formation and expansion. The pH value should be between 4.2 and 8.3. Of the three elements of fertilizer, potassium is the most needed, followed by nitrogen and phosphorus. Potassium fertilizer can promote the development of cambium, improve the photosynthetic efficiency of stems and leaves, accelerate the operation of photosynthetic products and increase the yield of root tuber. Nitrogen fertilizer promotes the growth of stems and leaves, increases the leaf area and increases the weight of stems and leaves; However, excessive application will promote the lignification of columnar cells in the roots, and the roots will not agglomerate or agglomerate less. Phosphate fertilizer can promote root growth, accelerate cell division and improve root quality. Compost and green manure have complete nutrients and slow and stable fertilizer efficiency, which can improve soil aeration and are most suitable for application.
Cultivation measures
It is an important link in sweet potato production to cultivate potato seedlings by using the germination characteristics of potato blocks. Potato chips should be varieties with many root scars and many buds, and 100 ~ 250g potato chips with good quality in summer and autumn should be selected as seed potatoes. Various seedling raising methods can be adopted, such as artificial heating hotbeds, various fire pits, or brewing hotbeds and electric hotbeds that use microbial decomposition to release heat energy. There are cold beds, hotbeds covered with plastic film in the open field and seedlings collected to use solar radiation for heating. Covering the seedbed with plastic film can increase air temperature and humidity, which is beneficial to seedling growth, increase seedling yield and increase the weight of 100 seedlings by about 20%. In the process of seedling raising, high temperature should be used to accelerate germination in the early stage. During the 10 days from sowing to complete emergence, the temperature gradually decreased from 35℃ to 28℃. When the seedling height is about 15cm, the temperature gradually drops from 30℃ to 25℃. The suitable water-holding capacity of bed soil is 70 ~ 80%, and the initial water is insufficient, the root system stretches slowly, the leaves are small and the stems are thin, which is easy to form old seedlings; Too much water and insufficient air affect germination; Under high temperature and high humidity, potato seedlings are delicate and grow in vain. The seedbed temperature must be kept at about 20℃ and the relative humidity is 60% within 3 ~ 5 days before picking seedlings. In order to avoid the high temperature in the film-covered seedbed, in addition to ventilation and heat dissipation, the bed soil should maintain a certain humidity to reduce the temperature in the film. In the process of germination, the nutrients needed by potato seedlings are mainly supplied by potato pieces. However, after root elongation or seedling harvesting for 2-3 times, nutrient soil or quick-acting nitrogen fertilizer should be applied. Loose bed soil and sufficient oxygen can strengthen breathing and promote metabolism. Severe hypoxia will suffocate seed potato cells and lead to seed potato rot. Be sure to pay attention to ventilation when covering with plastic film, which is conducive to the growth of strong seedlings.
Seedling raising time varies with different seedling raising methods. Generally, seedlings are raised in heated seedbeds about 65438 0 months before sowing, and in cold beds and open fields about 65438 0.5 months before sowing. The planting density should be 23 ~ 32kg potato chips per square meter. Pick seedlings in time to avoid affecting the quality of seedlings and the number of seedlings in the next crop. There are two ways to pick seedlings: cutting and pulling. Cutting seedlings has many advantages over pulling out seedlings: ① there is no wound on the surface of seed potato, which can prevent the invasion of germs; (2) The seed potato will not damage the root of the potato due to shaking; ③ Promote the growth of basal axillary buds and small branches, and increase the number of seedlings. Cutting seedlings should be more than 3 cm away from the bed soil, and cutting vines can prevent diseases and increase production.
Ridge farming is generally used for planting, which can deepen the soil layer, improve ventilation, accelerate the absorption and loss of heat, and has a large temperature difference, which is also beneficial to drainage and drought resistance. In areas prone to waterlogging and suitable for close planting in autumn, the yield of double ridges is higher than that of single ridge and small ridge. Timely early sowing can prolong the growth period and significantly increase the yield. When the soil temperature of potato in the main producing areas is stable at around 18℃ in spring and summer, the yield will be reduced by 1 ~ 1.5% every day after planting. Planting strong seedlings has the advantages of fast rooting, high survival rate and early potato production, and the yield of strong seedlings is more than 10% than that of weak seedlings.
Density Planting density varies with seasons, varieties and uses. There are 3000-5000 potatoes per mu in spring and summer, and 4000-6000 potatoes per mu in autumn and winter. Strive to reach the leaf area index of 3 ~ 4.5 at the peak of stem and leaf growth. Due to the continuous cutting of feed sweet potato stems and leaves, the density can be increased to 6000 ~ 8000 plants per mu under the condition of more fertilization.
In the north, general base fertilizer is applied, farmyard manure is applied again, and appropriate nitrogen-containing chemical fertilizer is used, so that nitrogen metabolism is dominant in the early stage of growth and carbon metabolism is dominant in the later stage. It is advisable to apply potassium dihydrogen phosphate at points or spray it in the middle and late stage in the phosphorus-deficient areas of Huanghuai River Basin. It is hot and rainy in southern potato areas, and it is emphasized to apply topdressing for many times, such as topdressing seedling fertilizer after sowing, topdressing potato fertilizer at the stage of branching and fruiting, topdressing potato fertilizer at the flowering stage of stems and leaves, and topdressing extra-root fertilizer at the later stage.
In the early stage of management, it is mainly to replenish seedlings in time, intertillage and weed for 2 ~ 3 times before closing the ridge, and cultivate the soil if the ridge surface collapses during heavy rain. Sweet potato vines will damage stems and leaves, disturb the even distribution of leaves, weaken photosynthetic efficiency, consume nutrients during regeneration of branches and leaves, affect the normal distribution of plant nutrients, and cause yield reduction. When measures such as topdressing and spraying chemicals are taken, vines should be protected to reduce the damage of stems and leaves.
The quality of potato harvest and operation is closely related to potato yield, drying rate, safe storage and processing. Sweet potato tuber is a vegetative body and has no obvious maturity. Generally, the local average temperature drops to 12 ~ 15℃. When the soil humidity is low in sunny days, we should pay close attention to harvesting. Harvest seed potatoes first, and then harvest edible potatoes. Potato pieces should be put into the cellar at any time, and some areas should be cut dry in time. No matter whether it is dug mechanically or manually, it is necessary to minimize leakage; At the same time, it is necessary to avoid potato chips from being broken, otherwise it is easy to be infected with diseases and lead to rot during storage.
The storage time of sweet potatoes in northern China is as long as half a year, and the external climate changes greatly. Potato itself still has respiratory function and various physiological and biochemical changes, and diseases are easy to spread and lead to rot. The main reason of potato rot during storage is low temperature, and the temperature at harvest should be above 65438 02℃. Underground pits are generally used for storage, and they are collected when they are collected; Thoroughly clean, disinfect and kill rats before entering the cellar. Strictly select potatoes, excluding potato pieces with broken skin, wounds, diseases, frost and water stains, and the storage capacity can only account for 80% of the storage cellar capacity. In the early stage of storage, high temperature callus treatment should be carried out, and the temperature in the cellar should be raised to 34 ~ 37℃ and the relative humidity is 85%, so that the broken potato pieces can form callus and prevent the spread of diseases. Then ventilate for a short time to dissipate moisture, and keep the cellar temperature 10 ~ 15℃ and the relative humidity of 85 ~ 90%; Strengthen heat preservation and cold protection in the middle and late stages to prevent potato piles from freezing below 9℃. The temperature has gradually increased before leaving the cellar, so pay attention to short-term ventilation to prevent hypoxia. Since the 1960s, it has been safer and more effective to popularize the "high-temperature large room cellar storage method", which is conducive to strengthening management. Use high-temperature healing treatment within 3 ~ 4 days after entering the cellar. Because of the large heat storage in the cellar, the accumulated heat can be used for heating economically. Fresh potatoes can be sliced or shredded, dried into dried potatoes and shredded potatoes for storage to reduce losses. The moisture content of dried potatoes during storage shall not exceed 1 1%. The warehouse is covered with wheat bran and straw, so that the temperature of the warehouse does not exceed 30℃.
Fungal black spot, nematode disease and fungal root rot are the main pests in the north; Bacterial potato blast and fungal scab are the main diseases in south China. Fungal soft rot is the main disease during storage. Select disease-resistant varieties, prevent metallurgical field diseases, implement crop rotation, establish disease-free seed fields, plant disease-free potato seedlings, and disinfect seed potatoes and seedlings with pesticides. There are many kinds of sweet potato virus diseases, and the symptoms of leaves are purple ring, yellow spot, leaf shrinking, leaf rolling, bright pulse and feather mosaic. Prevention and control methods can include cultivating virus-resistant varieties, eliminating diseased insects in potato fields, using stem tips to detoxify tissues, and cultivating disease-free seedlings. The main pests of sweet potato are sweet potato weevil and sweet potato wheat moth, followed by omnivorous pests such as mole cricket, cutworm and needle worm. In order to control the ant elephant, we should implement the rotation of paddy and upland, and take measures such as raising soil on ridges and cracks in the later stage. Agricultural techniques and pesticides can be used to control other pests.
The goal of breeding is to increase the yield and content of starch, protein and carotene. At the same time, it has good characteristics of germination, tuber formation and storage, and can resist drought, waterlogging, barren and pests, and can adapt to cultivation in different seasons. Breeding methods, such as clonal selection, make it easier to select mutant strains that meet the breeding objectives. Introduction and identification is a quick and effective method. Cross breeding is a breeding method combining gene recombination and clonal selection. Sweet potato is a short-day crop, which can blossom, pollinate and bear fruit naturally in Taiwan Province, Guangdong, Guangxi and southern Fujian. In other areas, artificial induction should be used to promote flowering, pollination and hybridization, and seedlings should be cultivated after seeds are obtained; Then asexual propagation is applied, and a variety is bred through multiple identification and comparison. Grafting combined with short-day treatment is widely used to induce flowering, with sweet potato varieties as scions and related plants as rootstocks; After grafting, the vines are hung, and the short sunshine is treated for 8 ~ 1 1 hour every day, and the temperature is controlled between 25 ~ 30℃ when budding. Avoid insect pollination when flowering. Cross between varieties as planned. Generally, the capsules and seeds will mature after 1 ~ 2 months. In addition, there are inbred line breeding, interspecific hybridization breeding and random group hybridization breeding.
There are many breeding methods of sweet potato varieties: ① Multi-stage seedling raising method. Using seedbed to accelerate germination, covering various nurseries with plastic film, planting and transplanting in stages, and propagating seedlings with seedlings. ② Single leaf node planting method. When pruning vines, one seedling per leaf node can improve the utilization rate of potato seedlings. ③ overwintering seedling raising method. Seedlings can safely overwinter in the seedbed, which can save seed potatoes, continuously cut seed potatoes and improve the propagation coefficient. (4) High-quality and high-density seed propagation methods. By selecting excellent varieties of potato pieces, cultivating large plants, cultivating a large number of branches and cutting single-node or double-node seedlings, the propagation coefficient is also very high.
Uses and processing
The contents of carotene, vitamin B 1, B2, C and other minerals in sweet potato are higher than those in rice and wheat flour. Some countries in Africa and Asia take this as their staple food; In addition, you can also make vermicelli, cakes, jam and other foods. Starch is extracted from fresh potatoes or dried potatoes in industrial processing, and is widely used in textile, papermaking, medicine and other industries. Hydrolysis products of sweet potato starch include dextrin, maltose, fructose and glucose. Aspergillus is used to saccharify starch in brewing industry to produce alcohol, liquor, citric acid, lactic acid, monosodium glutamate, butanol and acetone. Roots, stems and leaves can be processed into green feed or fermented feed, and the nutritional content is 3 ~ 4 times higher than that of general feed; Agricultural and sideline products such as fresh potatoes, stems and leaves and dried potatoes can also be used to make compound feed.
New sweet potato varieties and practical new techniques for high-yield cultivation
Sweet potato is a root crop, which is widely used. It can be used as food, feed and industrial raw material crops, and is planted in more than 0/00 countries in the world. The total output of sweet potato ranks seventh in the world. According to the statistics of FAO, in 2002, the total planting area of sweet potato in the world was 9.765 million hectares, the total output was 65.438 0.36 billion tons, and the average output of fresh potato was 654.38 0.3.9 tons/hectare. The total planting area and total output of sweet potato in China account for 62% and 84% of the world respectively, and the average output of fresh potato is 19.0 tons/hectare.
With the increasing population in China, the demand for agricultural products is increasing, the cultivated land area is decreasing, the water resources are becoming less and less, and the ecological environment is deteriorating. China's grain demand is under great pressure, and grain supply and demand are in a tight balance for a long time. Sweet potato has less input and more output, and the edible dry matter per unit area ranks first among all kinds of crops. Sweet potato has strong disaster resistance, drought tolerance and barren tolerance, and can also be planted in hilly and mountainous areas. In places where crops are difficult to grow, sweet potatoes can also get better yield.
With the continuous growth of China's national economy and the continuous adjustment and optimization of agricultural industrial structure, the role of sweet potato in ensuring national food security and energy security has become increasingly prominent. Sweet potato not only has large planting area and great yield potential, but also has good health care function and high conversion and utilization efficiency. Besides being used as feed and health food, it is also an ideal starch resource and energy crop. Many experts believe that sweet potato is one of the most ideal foods in 2 1 century and one of the most important renewable energy raw materials.
Judging from the current situation, the oil supply situation will be increasingly severe in a long historical period at present and in the future, and the development and utilization of biomass energy has been highly valued by all countries in the world. Sweet potato has high biological yield and high starch yield, which is an ideal raw material for producing fuel ethanol. As a new energy plant, it has attracted great attention from many countries. "Creation of New Energy Sweet Potato Materials and Breeding of New Varieties" has been included in the Tenth Five-Year Plan, aiming at cultivating new energy sweet potato varieties with high yield, high starch and high disease resistance. As a new energy plant, sweet potato will play an important role in China's energy security.
1. division of sweet potato production in China
1. division of sweet potato production in China
Sweet potato is widely planted in China, starting from Hainan Province in the south, reaching Heilongjiang Province in the north, and reaching western Sichuan mountainous area and Yunnan-Guizhou Plateau in the west. According to climatic conditions, farming system, topography and soil conditions, sweet potato cultivation in China is generally divided into five cultivation areas: spring potato area in the north, spring and summer potato area in Huanghuai basin, summer potato area in the Yangtze River basin, summer potato area in the south and autumn potato area in the south. Starch processing industry is the main industry in the northern potato area, and the middle and lower reaches of the Yangtze River are mainly used as feed, while the southern potato area has great development space in food processing industry.
South summer and autumn potato region. It mainly includes southern Fujian, Jiangxi and Hunan provinces, northern Guangdong and Guangxi, central Yunnan and southern Guizhou, and the area north of Chiayi in Taiwan Province Province. It has a humid monsoon subtropical climate with a frost-free period of 290-350 days and an annual average temperature of 18-23? C, annual sunshine hours 1500~2 140 hours, annual rainfall of 960~2690 ml. Summer potatoes were sown in May, and harvested in August ~ 65438+ 10, autumn potatoes were sown in early July to early August, and harvested in late June ~165438+early February. The growth period of sweet potato is about 120~ 150 days.
South potato region in autumn and winter. South of the Tropic of Cancer, including Hainan Province, southern Guangdong, Guangxi, Yunnan and Taiwan Province Province. It has a humid tropical monsoon climate with an annual average temperature of 18~25? C annual sunshine hours 1830~2 160 hours, annual precipitation15/kloc-0 ~ 2060 ml, frost-free period of 325~365 days, high temperature season of 8~ 10 month. Autumn potatoes are generally planted from early July to mid-August, harvested from mid-October to early February in 1 150 days. Autumn potatoes can also be planted in winter, and when they are harvested in the next spring, they become winter potatoes. Potatoes planted in winter are generally planted in June 1 1 and harvested in April-May of the following year, with a growth period of 170-200 days.
Especially because Hainan is located in the tropics, with abundant rainfall, sufficient light and heat, and no frost in all seasons, sweet potatoes can be planted all year round. In addition, sweet potato has strong stress resistance, is suitable for growth under various conditions, has great yield-increasing potential, wide application and broad development prospects, and has good value-added potential and market prospects.