(2) Overview of potatoes: According to the origin, taste and shape of potatoes, people give potatoes many interesting names, such as: Italian potatoes, French potatoes, German potatoes, American potatoes and Russian potatoes; China's Yunnan and Guizhou provinces are called taro or potatoes, Guangxi is called sweet potato, Shanxi is called yam egg, and most northeastern provinces are called potatoes. In view of the confusion of the name, botanists gave it a worldwide scientific name-potato. Potato has high yield and strong adaptability to the environment. 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. Heilongjiang Province is the largest potato planting base in China. When tuber is used for asexual propagation, seed potato can germinate and grow at soil temperature of 5 ~ 8℃, and the optimum temperature is 15 ~ 20℃. The suitable temperature for the growth and flowering of plant stems and leaves is 16 ~ 22℃. The optimum temperature for tuber formation at night is 10 ~ 13℃ (soil temperature is 16 ~ 18℃), and it forms slowly when it is higher than 20℃. When the temperature drops to -2℃, it will be frozen. The flowering and potato-bearing period is the period with the largest water demand in the whole growth period. Under drought conditions, irrigation per mu 15 ~ 20 tons is the key technical measure to ensure high and stable yield of potatoes. 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. (3) Potatoes, also known as potatoes and sweet beans, are native to Peru and Chile in the Andes of South America. /kloc-In the middle of the 6th century, a Spaniard brought potatoes from South America to Europe. At that time, people always appreciated the beauty of its flowers and used it as an ornament. Later, a French agronomist, Ann Obamanqi, discovered through long-term observation and personal practice that potatoes can not only be eaten, but also be made into bread. Since then, French farmers have begun to grow potatoes on a large scale. /kloc-At the beginning of the 0/9th century, when Peter the Great traveled in Europe, he bought a bag of potatoes with a large sum of money and planted them in the palace garden, which gradually developed into folk cultivation. Potato was introduced into China only 100 years ago. It is said that it was introduced by overseas Chinese in Southeast Asia. It is mainly planted in Northeast China, Inner Mongolia, North China and Yunnan-Guizhou regions where the climate is cooler, and now the potato planting area in China ranks second in the world.