Introduction of sweet potato
Also known as sweet potato, sweet potato, sweet potato, sweet potato, grandma Sha), different names of sweet potato, cold potato, cold potato, kudzuvine, kudzuvine, local radish (Records of Medicinal Plants in China), grass melon shavings (in Luchuan Materia Medica), shage and local radish (Jiangxi Herbal Manual).
The northern region mainly refers to sweet potato (sweet potato, sweet potato); In some parts of the south, the potato (Shage) is a different species.
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, sweet potato and red soil melon. Sweet potato is native to Peru, Ecuador and Mexico in South America. Because of its wide adaptability, strong reproduction, simple cultivation, high yield and stable harvest, rich nutrition and wide use, sweet potato is planted in11countries or regions all over the world, among which 10 1. The first batch of sweet potatoes in Europe was brought back by Columbus in 1492, and then introduced to Africa by the Portuguese and Asia by the Pacific Islands. Sweet potato was first introduced to China during the Wanli period of the Ming Dynasty. At that time, Chen Zhenlong, an overseas Chinese from Fujian, often went to Luzon (now the Philippines) to do business, and found that the yield of sweet potato 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 throughout the country. Its main producing area is located at latitude 40? South. At present, the total output of sweet potato ranks seventh in the world grain production, and it is predicted that it will rise to the fifth largest food 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 about130 million tons. Among them, Asia is the most important sweet potato producing area in the world, and its planting area and total output are more than 80% and 90% of the world respectively.
Sweet potato cultivation in China has a history of more than 400 years. According to historical records, the cultivation of sweet potato 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 via Liaoning and Jilin in the northeast, and reaching southern Tibet and Yunnan-Guizhou Plateau in the southwest. Sichuan basin, Huang Huai Hai, Yangtze River basin and southeast coastal provinces are the main sweet potato producing areas in China.
At present, the planting area of sweet potato in China is about 6.2 million hectares, and the total output is stable at 1 100 million 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.
Planting method of sweet potato
First, the hibernating seedling raising method of potato vine. The hibernating seedling raising method of potato vines is to leave the potato vines harvested in autumn for the next year as sweet potato seedlings.
1, vine cutting: after the sweet potato is harvested in autumn, select strong sweet potato vines without frost and disease, remove the leaves, keep the petiole of 1 cm, and cut each two sections.
2. Forced dormancy: soak the cut potato vines in 0.5% Amphitlin solution for two minutes, and take them out to dry the surface moisture.
3. Sand sieving: filter ordinary yellow sand with a sieve to remove large-particle sand and impurities, and sprinkle water. The humidity is such that the sand can be dispersed after being squeezed tightly.
4. Sand storage: firstly, dig a pit on the ground, the length and width are not limited, and the depth is1.2m (depending on the thickness of the frozen soil layer in winter, the appropriate storage temperature is 5- 10℃). Then the potato vines are laid flat in the pit by the method of one layer of vines and one layer of sand, leaving a gap of 1 cm between vines. The thickness of each layer of sand is not less than 3 cm, and the thickness of the top layer of sand is not less than 15 cm. The surface of the sand is covered with plastic film, and in areas with heavy frost, the film is covered with straw or grass curtain. When the sweet potato is planted in the next spring, the potato vine can be cut out. The hibernating seedling raising method of potato vine can save the land occupation of seed potato seedling raising and field management during seedling raising. After the potato vine stored in sand is taken out, a small number of new roots have been born, and after cutting, it can survive quickly and grow well, which can increase the yield per unit area of sweet potato by 15-20%.
Second, the potato root seedling method. Potato root seedling method is to transplant the potato roots harvested in autumn to a warm room or the balcony of a building, and cultivate the sweet potato vines throughout the winter and keep them as sweet potato seedlings.
1, after harvesting sweet potatoes in autumn, select strong potato vine roots without frost and disease, and leave 2-3 sections of vines on the upper part of the vine roots upward from the roots, remove the leaves and keep 1 cm petiole for later use.
2. According to the number of sweet potato seedlings, choose a suitable nursery site. In the greenhouse, ditch is opened (ditch width is 30cm, depth is 20cm), and the distance between ditch centers is 80cm. The sweet potato roots are planted on both sides of the ditch according to the spacing of 20cm, generally per square meter 12 plants. Pots can be used to plant sweet potato roots on the balcony of the house, and the method is the same as greenhouse cultivation.
3. In the greenhouse or above the floor of the house balcony (about1.6m from the floor), pull the iron wire of 14- 16 according to the row spacing of sweet potato roots, and tie some plastic ropes or hemp ropes to the iron wire, with one end of the rope tied to the iron wire and the other end tied to the sweet potato roots. After the vines on the sweet potato roots germinate, three robust buds are selected for each plant, one bud corresponds to a rope, so that the vines can climb up along the rope after the sweet potato roots germinate.
4. Newly-released sweet potato vines need to be manually wound on the rope, usually 1-2 days 1 time. When the sweet potato vines grow to 1.5-2 meters long and there are about 10 days before transplanting in the field, the sweet potato vines can be harvested, and the leaves are removed, and/kloc-can be kept. 10 days or so, the upper part of the potato vine sprouted buds, and the lower part sprouted certain roots, so it can be transplanted into the field.
Potato root seedling method has the characteristics of making full use of space and large seedling quantity, and potato root can also harvest a certain yield of sweet potato in spring. Using this method to raise seedlings, the temperature in the greenhouse or balcony should be controlled between 5-25℃, and it should not be too high or too low. Generally, 400-600 sweet potato seedlings can be cultivated per square meter.
Third, the potato vine seedling method. Potato vine seedling raising method is to select healthy potato vine without frost and disease after harvesting sweet potatoes in autumn, remove leaves, keep petiole of 1 cm, and cut it every two sections to form potato vine sections. The subsequent operation method is the same as potato root seedling raising method.
Growth habit of sweet potato
Growth period
The growth period of spring potato is 160-200 days, and that of summer potato is about1/kloc-0-0/20 days. According to the growth characteristics of red spring in the field and its relationship with climatic conditions, it can be roughly divided into three growth periods:
(1) Early stage (from seedling planting to pot sealing). Spring potato lasts about 60-70 days, and summer potato lasts about 40 days. At this stage, the growth of stems and leaves is slow, and the root system develops rapidly, which is mainly the period of growing fiber roots.
(2) Mid-term (from pot sealing to the peak of stem and leaf growth). Spring potato lasts about 50 days, and summer potato lasts about 30 days. At this stage, the tuberous roots expand slowly and the stems and leaves grow fast, which is a period of mainly growing stems and leaves.
(3) Late stage (from stem and leaf decline to harvest). Spring potato is after late August, and summer potato is after early September. This period is the main period of root swelling.
growing environment
(1) temperature. Sweet potato likes temperature and is afraid of cold. When planting seedlings, it will not root at 5-10cm, the ground temperature will be around 10℃, and it will take 5 days to root at 15℃, and it will root normally at 17- 18℃, and it will root at 20℃ for 3 days.
When the temperature is 25-28℃, the stems and leaves grow fast, and when the temperature is above 30℃, the stems and leaves grow faster, but the tuber expands slowly. Above 38℃, the respiratory consumption is high, and the growth of stems and leaves is slow. Below 20℃, the growth of stems and leaves is fast, and it stops at 15℃. If it lasts too long below 10℃, it will cause frost and the stems and leaves will die.
The higher the ground temperature is between 2 1-29℃, the faster and more tubers are formed, but the potato tubers are smaller. The ground temperature of 22-24℃ is favorable for the formation of tuberous roots. The ground temperature of 20-25℃ is most suitable for root tuber swelling, and when it is lower than 20℃ or higher than 30℃, it will swell slowly. When it is lower than 18℃, some varieties will stop swelling, and when it is lower than 10℃, it will be easily damaged by cold, and the root tuber will be frozen at -2℃. The larger temperature difference between day and night during root tuber expansion is beneficial to root tuber expansion and nutrient accumulation.
(2) illumination. Sweet potato likes light. Under the condition of sufficient light, its leaves are thicker, older, stronger and stronger, and its conducting tissues are developed, so its yield is higher. If the light is insufficient, the leaves will be yellow, with many fallen leaves, short leaf age, slender stems and vines, underdeveloped transport tissues, less transport of organic nutrients formed by assimilation to root tubers and low yield.
Long light exposure time per day is beneficial to the growth of stems and leaves, and the stems and vines become longer and the number of branches increases. Light exposure 12.5- 13 hours a day is more suitable for root swelling. Exposure to light for 8-9 hours a day is beneficial to bud flowering, but not suitable for root swelling.
(3) moisture. Sweet potato is a drought-tolerant crop, but too much water is not conducive to increasing production. Sweet potato is afraid of flooding, especially after the potato is planted, which has a great influence on the yield. The uneven growth rate inside and outside the root tuber is caused by the uncertainty of soil moisture, and the phenomenon of skin cracking often occurs. In short, sweet potatoes are afraid of both waterlogging and drought, and the masses say: Dry long firewood root, wet long fibrous root, dry long tuberous root. ? In order to obtain high yield of sweet potato, irrigation should be timely and appropriate according to specific conditions, and drainage should be thoroughly carried out in time, and intertillage should be strengthened to conserve moisture in dry land.
(4) nutrients. Sweet potato has strong ability to absorb fertilizer and is barren-tolerant, but sufficient fertilizer must be applied to achieve high yield. Besides nitrogen, phosphorus and potassium, sulfur, iron, magnesium and calcium also play an important role. Among the three elements, sweet potato requires the most potassium, followed by nitrogen and the least phosphorus. According to the analysis, every 1000 Jin of sweet potato contains 3.5 Jin of nitrogen, 0.75 Jin of phosphorus/kloc-0 and 5.6 Jin of potassium. Therefore, increasing the application of potassium fertilizer and timely and appropriate application of nitrogen and phosphorus fertilizer can significantly increase production.
(5) soil. Sandy loam and sandy soil with deep soil layer, rich organic matter, loose, good ventilation and drainage performance are better. When the soil is sticky, the root bark is not good and rough, the potato shape is irregular, the yield is low, and it is not resistant to storage. However, sandy loam and sandy soil generally have low fertility and poor water holding capacity, so we should gradually improve the soil fertility through fertilization and other measures to obtain high yield. Sweet potato is more resistant to acid and alkali, and its PH value is about 4.5-8.5, but 5.2-6.7 is suitable. When the soil salt content exceeds 0.2%, sweet potato should not be planted.
See how to grow sweet potatoes and see:
1. A new method of sweet potato seedling raising
2. Techniques for planting sweet potatoes
3. Planting techniques of sweet potato in Nongguang Tiandi
4. Techniques for planting sweet potatoes
5. Technical methods for high yield of sweet potato