TobaccoFlue-cured tobacco, also known as fire tube flue-cured tobacco, originated in Virginia, USA, and has a special morphological feature, and is therefore also known as the Virginia type. The main feature of flue-cured tobacco is that the plants are tall and the leaves are sparsely distributed. The average plant height is 120-150cm, and the leaves are 20-30 pieces per plant. The leaves are thick and moderate, and the quality of the middle part is the best. It is not advisable to apply too much nitrogen fertilizer in cultivation. The leaves mature from bottom to top and are harvested in several stages. The original preparation method was also drying, and later (1869), it was changed to fire tube baking, which was prepared in the baking room and golden brown after baking. Its chemical composition is characterized by high sugar content, low protein content and moderate nicotine content. Flue-cured tobacco is the largest type of tobacco in China and the largest cultivated area in the world. It is also the main raw material of the cigarette industry and is also used as a pipe tobacco. The countries producing flue-cured tobacco in the world are mainly China, the United States, and India, followed by Brazil, Zimbabwe, Thailand, Canada, and Japan. China's flue-cured tobacco planting area and total output rank first in the world. The key production areas include Henan, Shandong, Yunnan, Guizhou, Heilongjiang, Hunan, Hubei, Shaanxi, Anhui and other provinces. Sichuan, Guangdong, Fujian, Liaoning, Jiangxi, Guangxi, Jilin and other provinces (districts) also have a large area of cultivation.Sun-curedTobacco leaves are made of sunlight, mainly red and yellow. Generally, the appearance characteristics and chemical components of the yellow-light smoke are similar to those of the flue-cured tobacco, while the red-light smoke is different from the flue-cured tobacco. The leaves of red sun-cured tobacco are generally less, the flesh is thicker, harvested once or harvested once, and is mostly dark brown or brown after drying. The quality of the above leaves is the best. Tobacco leaves generally have low sugar content, high protein and nicotine content, strong smoke and strong head. Sun-cured tobacco is mainly used for pipe tobacco, shisha and cigarettes, and also as a raw material for cigar core leaves, bundles and snuff, and chewing tobacco. In addition, some sun-cured tobacco can also be processed into insecticides. The main countries in the world that produce sun-cured tobacco are China and India. There are sun-cured tobacco plants in all provinces of China, but the distribution is scattered. Sichuan, Guangdong, Guizhou, Hunan, Hubei, Yunnan, Jilin, Shandong, Shaanxi and other provinces are concentrated.Yellowing tobaccoSun-cured tobacco is divided into light-colored sun-dark smoke and dark-colored yellow-smoke smoke according to the depth of leaf color. There are three kinds of preparation methods: semi-baked, half-baked, sun-dried and sun-dried. In general, yellowing tobacco is close to flue-cured tobacco, especially light-colored sun-cured tobacco. It is similar to flue-cured tobacco in terms of shape, chemical composition, smoke, and taste. Dark yellow sun-cured tobacco is a type between light-colored yellow-light smoke and red-light smoke. Compared with light-colored yellow-light smoke, the leaf color is deeper, the nitrogen content is more, and the sugar content is lower. These differences, in addition to the variety factors, are mainly caused by different cultivation conditions and modulation methods. The main producing areas for yellowing tobacco include Nanxiong in Guangdong, Huanggang in Hubei, Junxian, Luohe in Jilin, Guangfeng and Shangrao in Jiangxi.Red smokeIt refers to the reddish-brown tobacco leaves after drying. This red sun can be subdivided into old red, red and dark brown. Red sun smoke is a raw material for making mixed cigarettes, dry tobacco and pipe tobacco. Good quality red sun smoke is also the raw material for making cigar core leaves and inner skin. For example, Guangdong Heshan Tobacco, Sichuan Suoyan, Guizhou Puning Tobacco, etc., belong to the red sun.Playing tobaccoIt refers to the tobacco leaves that are first stacked and yellowed before being brewed. It can be used as a raw material for dry tobacco and is extremely valuable. For example, Jilin Weihe, etc., belong to the sun-cured tobacco.