synonymsweet potato(Convolvulaceae plants) generally refer to sweet potatoes (Convolvulaceae plants)
Sweet potato（Ipomoea batatas(L.) Lam.），The tumor inhibition rate was 98.7%,[19]It belongs to Convolvulaceae, sweet potato.[23]It has milk.The tuberous root is white, red or yellow;Stems with adventitious roots;The leaves are broadly ovate or ovate heart-shaped, with dark green, yellow green, purple green, etc,[13]The front end is acuminate, and the base is cordate or nearly flat;Corolla is pink, white, lavender or purple, bell shaped or funnel shaped, hairless;The chrysanthemum fruit is oval or oblate;[1]Because sweet potatoes are cross pollinated, self pollination often does not bear fruit, so sometimes only flowers do not bear fruit.[13]
Sweet potato is native to South America and the Greater and Lesser Antilles Islands, and has been widely cultivated in tropical and subtropical regions of the world. However, it has also been successfully planted in some northern regions, such as Heilongjiang Province, and is widely cultivated in most regions of China.[13]Sweet potato has strong adaptability. It likes warmth and light, but is not frost resistant. It is drought resistant and alkali tolerant. It is suitable for planting on fertile sandy soil with good drainage. It is a kind of crop that is easy to ensure harvest.[14]
Sweet potato is a high-yield and adaptable food crop. In southern China, there is a saying that "one can produce sweet potato for half a year",[15]It is closely related to industrial and agricultural production and people's life;In addition to being the main grain, block eradication is also an important raw material for food processing, starch and alcohol manufacturing industries;Roots, stems and leaves can be used as good fodder;[13]This species has large root tubers and strong climbing ability. It is mostly used for trellis construction of three-dimensional landscape of fruits and vegetables in gardens.[20]Sweet potato can also be used for medicine. It is recorded in the book "Seeking the Source of Materia Medica" that sweet potato can cool blood and promote blood circulation, broaden the intestines and stomach, relieve constipation, remove blood stasis and visceral toxins, relax muscles and collaterals, and stop bleeding, heat and thirst. It is the best choice for lying in women.It can be eaten with fish and snakehead to regulate the middle and tonify the deficiency.[16]
Sweet potato was first planted in Central AmericaMexico、ColumbiaThe Spanish brought it to the Philippines and other countries to plant it,[2]Sweet potatoes were first introduced into China during the Wanli period in the late Ming Dynasty. They entered China by three routes - Yunnan, Guangdong and Fujian.[3]
It is generally believed that sweet potatoes were introduced into China during the Ming Dynasty, and the first person in China to introduce sweet potatoes wasChen YiAccording to historical records, Chen Yi isGuangdongDongguanIn the eighth year of Wanli (1580) of the Ming Dynasty, a man from Humen North Gate, wearing cloth clothes and carrying a package, took a friend's merchant ship from Humen to Annan (today's Vietnam).After arriving in Annam, the local chief presented an official dish when he received them. This dish was sweet, soft and smooth. In addition to being very delicious, it could also satisfy hunger. It was called sweet potato.Chen Yi then paid special attention to the growth habits and cultivation methods of sweet potatoes. Two years later, in 1582, he risked his own life to buy the soldiers and hid the potato seeds in the bronze drums in order to secretly bring them back to the country.Chen Yi bought 35 mu of land in front of his grandfather's tomb on the mountainside of Xiaojie Mountain in Jinzhou, Humen, and began to plant a large area of sweet potatoes.After the successful harvest, he decided to spread this food widely, and chose his birthday to stay with sweet potatoes forever.As "the first person to introduce sweet potatoes in China", Chen Yi has made great contributions to opening up food sources for China.[4-5]
During the Ming Dynasty, he spent many years in Luzon (i.ethe Philippines）BusinesspersonFujianChanglepeopleChen ZhenlongSame as its sonChen JinglunSee the local planting of a root crop called "sweet potato". The root crop is "as big as fist, red skin, crisp and juicy heart, edible both raw and cooked, high yield, wide planting and barren tolerance".Chen Zhenlong was determined to introduce sweet potatoes to China when he thought of his hometown, Fujian, where there were many mountains and few fields, the land was poor and the food was insufficient.In 1593, the PhilippinesSpainUnder colonial rule, sweet potatoes were regarded as rare goods and "forbidden to leave the country".After careful planning, Chen Zhenlong "twisted potato vines into the water rope" and smeared mud on the rope surface. In the early summer of 1593, he skillfully avoided the inspection of the colonial checkpoint and "crossed the sea".Sailing for seven days, returning to Fujian in late May of the lunar calendarXiamen。The sweet potato is called "sweet potato" by Fujian people because it comes from outside China.The introduction of sweet potatoes by the Chen family was made in the Ming DynastyXu Guangqi《Complete Book of Agricultural Administration》、Talking about moving《Jujube forest miscellaneous》And so on.
When sweet potato was introduced into China, it showed its excellent characteristics of strong adaptability and no land, and its high yield was "ten stones per mu, 20 times better than seed millet".In addition, "moist and edible, or boiled or ground into powder, raw food like kudzu, cooked food like honey, taste like water chestnut", so it can quickly spread to the mainland.seventeenth centuryAt the beginning, the flood in the south of the Yangtze River was serious, the grain was not harvested, and the hungry people were displaced.At that time, scientist Xu Guangqi was living in Shanghai because of his father's death. He learned that sweet potatoes planted in Fujian and other places were good crops for famine relief, so he introduced them from FujianShanghai, then toJiangsuIt's spread and the harvest is very good.
Chen Chuangui, the fifth grandson of Chen Zhenlong, introduced sweet potatoes toZhejiang, his son Chen Shiyuan went with several younger generationHenan、Hebei、ShandongAnd other places widely publicized to encourage the planting of sweet potatoes.It is reported that when Chen Shiyuan taught how to plant sweet potatoes in the ancient town of Jiaozhou, Shandong Province, he personally prepared the land and raised seedlings, cut vines and cut cuttings, and harvested more potatoes in autumn, so he spread the word from one to another, competing to plant.Sweet potatoes were soon popularized in North China.
During the Qianlong period of the Qing Dynasty, many places were planted by the government.stayHebei provinceThe emperor "directed the province to plant".As a result of the active promotion, sweet potatoes quickly spread throughout the country, and became the second only to ChinaRice、wheatandCornIs the fourth largest food crop.In 1733, sweet potatoes arrivedSichuan, arrived in 1735Yunnan, arrived in 1752Guizhou。Since then, sweet potatoes have been everywheresouthwest。[6]
morphological character
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annualHerb, underground part with round, oval or spindle shaperoot tuberThe shape, skin color and flesh color of root tubers vary with varieties or soils.Stems lie flat or rise, occasionally twining, multi branched, cylindrical or angular, green or purple, sparsely pubescent or glabrous, and stem nodes are prone to adventitious roots.
Sweet potato leaves[22]
bladeThe shape and color often vary from variety to variety, and sometimes there are different leaf shapes on the same plant, usually wide oval, 4-13 cm long, 3-13 cm wide, whole or 3-5 (- 7) split, wide oval, triangular oval or linear lanceolate lobes, the base of the leaf is heart-shaped or nearly flat, the top is gradually pointed, both sides are sparsely hairy or nearly hairless, and the leaf color is thick green, yellow green, purple green, etc,The color of the top leaf is one of the characteristics of the variety;Petiole varies in length, 2.5-20cm long, sparsely pubescent or glabrous.
CymeAxillary, 1-3-7 flowers gathered into umbels, peduncle 2-10.5 cm long, slightly thick, glabrous or sometimes sparsely hairy;BractSmall,lanceolate, 2-4 mm long, apical awn or cuspidate, caducous;Pedicel2-10mm long;sepalIt is oblong or elliptic, unequal in length, the outer sepal is 7-10 mm long, the inner sepal is 8-11 mm long, and the top suddenly becomes awn pointed, glabrous or sparsely ciliated;Corolla pink, white, lavender or purple, bell shaped or funnel shaped, 3-4 cm long, glabrous outside;Stamens and styles are concealed, and filaments are hairy at the base;Ovary 2-4 locules, hairy or sometimes glabrous.
The flowering habit varies with varieties and growth conditions. Some varieties are easy to blossom, while others will blossom when the climate is dry. They often blossom in areas with high temperature and short sunshine, and rarely blossom in areas with low temperature.capsuleOval or oblate, with pseudomembrane divided into 4 chambers.Seeds 1-4, usually 2, glabrous.Because sweet potatoes are cross pollinated, self pollination often does not bear fruit, so sometimes only flowers do not bear fruit.[1]
Habitat
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Sweet potatoes are native to South America and the Greater and Lesser Antilles Islands, and are now widely cultivated in tropical and subtropical regions around the world.There are about 500 species in this genus and 29 species in China.[21]It has also been successfully planted in some northern regions, such as Heilongjiang Province, and is widely cultivated in most regions of China.
Sweet potato
Growth habit
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one
Temperature:Sweet potato likes temperature, is afraid of cold, and is not cold resistant. The suitable growth temperature is 22-30 ℃, and stops growing when the temperature is lower than 15 ℃.Different growth periods have different temperature requirements. The temperature in the bud stage should be 18-22 ℃. Too high or too low temperature will affect the germination rate.The temperature at seedling stage should be 22-25 ℃, the temperature at stem and leaf stage should be 22-30 ℃, and the temperature at stem and leaf stage should not be lower than 16 ℃, otherwise it will hinder its growth and even stop growing;If the temperature is lower than 8 ℃, the plant will be frostedwitheredDeath.The temperature at root block stage should be 22-25 ℃.Appropriate temperature can promote the growth of plants in each growth period, and ensure the number and expansion of root blocks.[7]
two
illumination:Sweet potato likes light and is a crop with short sunshine.The plant has high requirements for light energy during growth, and is a shade intolerant cropStem and leafAt the beginning of the period, the time of light energy will be longPhotosynthetic efficiencyThe higher it is, on the contrary, it will reduce photosynthetic efficiency and affect plant growth.The sunshine time should be 8-10 hours per day. Adequate light can not only promote flowering and root block formation, but also make more nutrients accumulate on root block and promote root block expansion.[7]
three
water content:Sweet potato has strong drought resistance and adaptability, and the soil water capacity should be controlled at 60-70%. The suitable water conditions can meet the needs of different growth periods.The soil water capacity should be 60-80% in the bud stage, seedling stage, stem and leaf stage, branch and tuber setting stage, etc,Water capacityToo low will cause slow root growth, resulting in weak seedlings, short seedlings and diseased seedlings;The soil water holding capacity at root block stage should be 60-70%, which can effectively promote root block formation and expansion.The water in this period should not be too large. In case of rainy days, strengthen management, pay attention to reducing ponding in the field, and improve drainage capacity.[7]
four
Soil:Sweet potato toleranceAcid-base propertyGood, strong adaptability to soil environment.Its root system is developed and its fertilizer absorption ability is strong, so it is better to select deep soil layer, loose soil, good soil quality, strong irrigation and drainage abilityPH valuePlot between 4.2-8.3.[7]
five
Nutrition:In the process of plant growth, it is necessary to meet the needs of various fertilizers and nutrients in different growth periods, and apply appropriate amount ofnitrogenous fertilizerIt can promote the growth of leaves, stems and branches, and promote photosynthesis, but it should not be excessive, otherwise it will cause lignification of root cells, affect the number of root blocks, and will not form root blocks in case of severe excess.Moderatephosphate fertilizerIt can accelerate cell division, promote root growth, facilitate nutrient absorption and improve root quality.Appropriate potassium fertilizer can improve photosynthetic efficiency, promote root growth, increase the number of root blocks, promote root block expansion and weight increase, and increase yield.The test shows thatpotash fertilizerThe effect on sweet potato yield was the largest, followed by nitrogen fertilizer and phosphorus fertilizer.Farmers should understand the characteristics of sweet potato fertilizer needs, but they should not increase potash fertilizer at will because potash fertilizer can increase production. They should apply nitrogen fertilizer, phosphorus fertilizer, etc., apply fertilizer scientifically, improve fertilizer efficiency, and meet their growth needs.[7]
Distinction of recent species
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1. The main difference between purple leaf 'sweet potato Ipomoea batatas' Black Heart' and the original species is that the leaves are heart-shaped and purple.[21]
2. The main difference between the 'Golden Leaf' sweet potato Ipomoea batatas' Marguerite 'and the original species is that the leaves are heart-shaped and golden yellow.[21]
3. The main difference between the colored leaves' Ipomoea batatas' Rainbow 'and the original species is that the leaves are heart-shaped, with sharp tips, green leaves, and white or purple patches on them.Purple leaf sweet potato, golden leaf sweet potato and other ornamental varieties have strong adaptability, vigorous growth, dense leaves, beautiful leaf color, long viewing period, can quickly cover the ground, achieve landscape greening effect, and are excellent ground cover plants, suitable for use in sunny areas.Can also be potted and suspended.[21]
Reproductive methods
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grow seedlings
Early maturing varieties should be nurtured in large shed+small arch shed+plastic film with three layers of heat preservation. After emerging early, they should be cultivated with plastic film mulch to supply the market early;Conventional cultivation can adopt small arch shed+two layers of plastic film for heat preservation.The seedbed is about 1.0m wide and 15-20cm deep. The bottom of the bed is covered with organic fertilizer and then watered and covered with soil.
Sweet potato seedling
The selection of seed potatoes shall have the typical characteristics of the variety, free of pests and diseases, and 100-250 grams of potato blocks.The seed density is about 3cm interval between tubers. After the seed tubers are arranged, they are covered with soil with a thickness of 2-3 cm, but not more than 5cm, so as not to affect the emergence of seedlings.Remove the mulch film when 60% of the tubers sprout.When the temperature is above 20 ℃ in sunny days, open the arch shed film and the greenhouse film for ventilation at both ends to prevent seedlings from burning at high temperature, maintain the bed temperature of 25-30 ℃, and the humidity shall be subject to the dry or wet bed soil.When the potato seedlings are 20-25cm long and have 6-8 complete leaves, they can be cut and planted in the field.[8]
transplant
When the average temperature is above 15 ℃, the seedlings can be cut and planted in the field. Due to the low temperature in the early stage (late April to mid May), plastic film mulching can be used for cultivation.When planting, 4 nodes are inserted horizontally or obliquely into the soil. In case of drought, two leaves are exposed to the ground, and the rest leaves are buried in the soil to facilitate the survival of potato seedlings and the distribution of tubers, improve the commodity rate and yield. The planting density is 4000 plants/667 square meters, and the plant spacing is 20 cm.[8]
Sweet potato field
cultivation techniques
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Management and protection
Sweet potato management
Soil preparation and fertilization: soil preparation shall be carried out in sunny days, and the soil shall be broken and thinned.After leveling, fertilizer strips are applied at the bottom of the ridge, with a ridge spacing of 80 cm and a ridge height of about 20 cm.The special organic compound fertilizer can be used as fertilizer. When the planting area is large, it is required to measure the soil n, p, k and organic matter. In the south, it is also required to measure the soil pH value.Common compound fertilizer is not recommended.[8]
Pruning and topping: For potato fields with many branches and vigorous growth, two or three branches can be cut off with scissors, so that nutrients can flow back and more nutrients can be obtained for potato blocks.Topping can regulate nutrient movement and promote nutrient transportation to roots.When the potato seedlings grow to 40-60 cm, remove the tender tip, and when the branches grow too fast, remove the tender tip.[8]
Top dressing in time: the seedling fertilizer shall be raised about 15 days after planting in combination with the first intertillage every 667mtwoApply 750-1000kg of thin human and livestock manure or 2.5kg of urea.Potato forming fertilizer at the stage of branch and tuber formingTopdressingGenerally, it is carried out within one month after planting in combination with the second intertillage, mainly nitrogen fertilizer, combined with phosphorus and potassium fertilizer.Crack fertilizer After the stem and leaf are sealed, the root tubers grow faster, and fertilizer is applied when cracks appear on the ground.Every 667mtwoUrea dressing 1.5kgcalcium superphosphateLeaching solution 10kgpotassium sulphate3kg of water and 150-200kg of water are added to prepare nutrient solution, which is irrigated along the seam in the afternoon of cloudy or sunny days, and the top dressing is required to be uniform.[8]
keep in storage
Store sweet potatoes
Early and middle maturing varieties will be harvested at the end of August and early September, and late maturing varieties will be harvested in the middle of October.The latest harvest time is before frost.No harvesting in rainy days.When harvesting, it is necessary to dig, load, transport and unload gently to prevent potato skin and potato pieces from being bruised.The storage temperature shall be 10-15 ℃,Relative humidity of airAt 85% - 90%, the storage place should be clean and sanitary, and the rodent and poison prevention work should be done well.At the same time, thermal insulation measures shall be taken to prevent frostbite and extrusion, and ventilation and heat dissipation shall be paid attention to.[9]
Disease and insect control
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Diseases mainly includea virus、Black spot、Purple feather disease。Control method: select disease-free seed potatoes, soak them in 2000 times of 80% 402 medicament for 5 minutes before breeding and seeding, and 25% of cuttings can be usedCarbendazim1500 times liquid or 50%TobuzinImmerse in 2000 times liquid for 10 minutes.
Insect pests mainly includeSpodoptera litura, sweet potato leaf beetle.The Spodoptera litura can remove 1000 times of liquid and 5% of liquid with 10% in late JuneChlorfluazuron 800-1000 times liquid or 48%lorsban 1000 times liquid spray.Sweet potato leaf beetles can be cut 30 days later.Use 20% triazophos emulsifiable concentrates 600 times or 2.5%Enemy killing4000 times liquid spray.[9]
Key values
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Edible value
Sweet potato is a high-yield and adaptable food crop. In southern China, there is a saying that "one can produce sweet potato for half a year".[15]Sweet potato is a nutritious and rich natural nourishing food, which containsprotein、Fat、Polysaccharide、phosphorus、calcium、potassium、Carotene、vitamin A、vitamin C、vitamin E、vitamin Bone、vitamin BtwoAnd 8 kindsamino acid。According to scientists' analysis, its carotene content is 3.5 times that of carrots;The content of vitamin A is 100 times that of potato;Sugar, calcium and vitamin BoneVitamin BtwoIts content is higher than that of rice and flour.The edible part of every 100g fresh potato block contains 29.5g carbohydrate, 0.2g fat, 20mg phosphorus, 18mg calcium and 0.4g iron.These substances play an important role in promoting the activity of human brain cells and secreting hormones, enhancing human disease resistance, improving immune function, and delaying intellectual decline and body aging.The Ministry of Health of Japan has listed it as an important food for dietotherapy.[10-11]
Diet food
The fat content of sweet potato is very low (0.2%), which is incomparable with other foods.The content of unsaturated fatty acids is very rich.Take it as the staple food, insist on eating one meal every day, and its richcelluloseIt makes people feel "full of food and drink" and feel comfortable.At the same time, it can not only prevent the absorption of fat and cholesterol in the intestine, but also decompose thecholesterolIt can promote the metabolism of lipids, effectively prevent human nutrition surplus, resist obesity, and achieve the goal of weight loss.[10]
Longevity food
As early as the Ming Dynasty, sweet potato was a Chinese medical expertLi ShizhenIt is listed as "longevity food".In recent years, with the development of society, the "social status" of sweet potato has also been improved. Many countries in the world call it "longevity food".Its function is to quickly neutralize the acidic substances produced by rice, noodles, meat, eggs and other foods in the human body, maintain the weak base balance of human blood, and absorbCaroteneConvert to vitamin A.Both raw and ripe sweet potatoes have mucin.This mucin is a mixture of polysaccharide protein, which belongs to collagen and polysaccharide.It can effectively preventVascular wallThe deposition of upper fat can maintain and increase the elasticity of arterial wall and reduce subcutaneousFatIt can prevent the flaccidity and contraction of the connective tissue in the liver and kidney, prevent fatigue, restore energy, and preventconstipation, strengthen your body and prolong your life.[10]
Avoid eating
one
Eating cold sweet potatoes is easy to cause stomach discomfort.Sweet potatoes produce acid in the stomach, sogastric ulcerandgastric acidToo many patients should not eat.
two
Rotten sweet potatoes (sweet potatoes with black spots) can make people poisoned and cannot be eaten.[12]
three
Rootstock vegetables such as sweet potatoes contain a lot of starch, which can be processed into noodles for eating, but they often addalum。Excessive consumption will lead to aluminum accumulation in the body, which is harmful to health.
four
Sweet potato contains "gasifying enzyme", so don't eat too much at one time, and it can be eaten with rice and noodles, and with pickles or vegetable soup to avoid heartburnAcid spitting water, belly expansion, exhaust, etc.
Medicinal value
Disease prevention: Potato cubes contain rich and specialvitamin C、vitamin EandPotassium。Vitamin C can obviously enhance the resistance of human body to cold and other viruses;Vitamin E can promote people's libido and delay aging.Potassium can effectively prevent hypertension, stroke and cardiovascular disease.Japanese scientists found that the tuber contains a kind ofchicken、duck、fishCollagen mucoprotein obtained from meat, which can keep human bodyarteryVascular wallIts elasticity can effectively prevent arteriosclerosis.[10]
Good medicine: It has high medicinal value.Ancient Chinese medical scientists have long discussed the efficacy of potato tubers in curing diseases.Ming Li Shizhen《Compendium of Materia Medica》It says: "Sweet potato has the effects of tonifying deficiency, invigorating qi, strengthening spleen and stomach, and strengthening kidney yang".According to the Golden Potato Biography, "it can cure dysentery, diarrhea due to alcohol accumulation, damp heat, infantile malnutrition" and other diseases.It is recorded in "Materia Medica Seeking the Source" that sweet potato can cool blood and promote blood circulation, widen intestines and stomach, unblock constipation, remove blood stasis and visceral toxins, relax muscles and collaterals, stop bleeding, heat and thirst, and is the best choice for lying in women.It can be eaten with fish and snakehead to regulate the middle and tonify the deficiency.The milky white slurry in the raw potato block is a good medicine for defecation, blood circulation and muscle spasm inhibition;It has special effect on eczema, centipede bite, herpes zoster and other diseases.The method is to mash the raw potato, squeeze the juice, and apply it to the affected part, which can be cured several times.[10]
economic value
Sweet potato is closely related to industrial and agricultural production and people's life, and has many functions.[13]
High quality feed: sweet potatoes are all high quality feed for fattening pigs. They can be eaten alone and can be mixed with other grains, such asCorn, Qingke, orgreen grass, Mixed feeding of leaves.Leaves and tendrils can be eaten fresh, dried and crushed, and boiled with chaff.One month before pig body shaping (skeleton lengthening) or slaughtering, eating cooked potato blocks alone or mixed with corn is particularly effective in fattening and fattening, just like using "fattening agent", which generally increases 0.5-0.8kg of meat per day. This is a successful experience of fattening pigs in Chenggu County, Shaanxi Province.Avoid foodBlack spotSuffer from potato lumps to prevent the pig from being poisoned and dying.[10]
Wide range of uses: potato blocks are suitable for processing a variety of products, including soy sauce, preserved fruit, maltoseCalcium gluconate, and can brewLiquor and Spirits, Extractalcohol。The potato residue after extracting starch can be produced againCalcium citrate。Its starch is an important raw material for producing plasticizers and advanced absorbent resins.Processed dried potato, mainly exported toSoutheast AsiaAll places.[10]
Extracted starch: its starch can be eaten in a wide range. It can be mixed with various meats to make food balls, steamed with flour, or baked separately, or stirred with jelly.
[10]
Plant culture
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proverb
"Never marry a sister on the back of a bamboo head, or a pig dish without a sweet potato": Taiwan's Hakka saying goes that the old society was generally poor, and they were unwilling to marry their daughters to the more impoverished mountain forests behind the bamboo head. Because the mountains were steep, they worked up the mountain before sunrise, and they had to drag their tired and hungry bodies. The burden on their shoulders was not two baskets full of sweet potatoes,It's just a shoulder of pig dishes（Sweet potato vineandSweet potato leaves）On the way home, I have no leisure.
"Take responsibility when the time comes, and cook when there is no riceSweet potato soup”: As a Taiwanese saying goes, it means that when you reach the bridge, you will be straight. You don't need to worry too much. When it comes to crisis, there will be a way of coping.
"Sweet potatoes are not afraid of falling soil and rotting, but only for the branches and leaves to be passed down from generation to generation": a Taiwanese proverb has a strong meaning and vitality,ingrainedAs long as you plant it, it can continue to grow, just like the spirit of Taiwanese, hard working and rooted.
"It is not hard to eat when there are sweet potatoes in the soil";In Fujian, Jiangxi and other places, the older generation also called sweet potato "muddleheaded sweet potato" because of its simple and honest posture. With the boom of animation culture and the popularity of cute and funny elements, most of them were renamed as "meng sweet potato".Sweet potatoes are high in yield. The Red Army often suffered from hunger when fighting guerrillas. Later, knowing that planting sweet potatoes can effectively deal with hunger from mountain farmers, they learned to plant some sweet potatoes in front of and behind houses. This slogan spread among the military and the people.
