Effect Of Fertilization Levels And Topping On The Growth, Yield And Quality Of Tobacco

As an important cash crop, tobacco yield and quality are equally important. Its leaves is not also the main photosynthetic production sites (source) which can product their assimilation in tobacco, but also storage of the main sites and the formation of organs of economic output (sink), and whether coordinate or not the relationship between source and sink will directly affect the level of economic output of tobacco. in agricultural production, improved management techniques is not only the important way of improving the cultivation of tobacco leaf quality, but also the important foundation in enhancing the income of agricultural production of tobacco, the quality growth and production factors of tobacco is depend on Fertilization and topping regulate the distribution of photosynthetic products and promote the growth of tobacco leaves, so fertilization and topping are the effective regulation on tobacco production and quality. The research try to establish a reasonable cultivation system of tobacco to promote the effective use of nutrients to improve quality and yield of tobacco through a randomized research of the impact of source-sink relationship between fertilization and topping on tobacco, the results are as follows:1. Most indicators such as plant height, maximum leaf length and width, stem circumference are positive correlation with fertilization. This proved that increasing the fertilization level contribute to individuals growth and yield formation and the treatment of topping had no significant effect on low leaves indicators of tobacco, but the time of topping are negatively correlated with the central-leaf and up-leaf physical indicators, early topping can promote the development of tobacco, which is increase tobacco production.2. The relative content of Chlorophyll was positively correlated with fertilization, photosynthetic rate and transpiration rate was increased firstly and then decreased as the fertilizer rate change. Within a certain extent, fertilizer can promote photosynthesis, but also inhibited by excessive fertilizer. Topping tobacco would weakened photosynthetic rate (Pn) and transpiration (Tr) and inhibit photosynthesis.3. With the increased fertilizer, dry weight of root account for the larger percentage of the total dry weight, but was negatively correlated with the ratio of Strain/shoot, fertilization contribution to the underground are higher than above ground, increase nicotine and nutrient in a significant on each part of tobacco, the effects on the upper leaves which increase in nicotine accumulation effect mainly in the tobacco late growth stage, high fertilizer level cannot help synthesis of reducing sugars in tobacco plant Topping treatment has little effect on the low-leaf, but more significant accumulation on the up-leaf, topping are negatively correlated with material accumulation and Early or late of topping significantly play the roles in regulating the nicotine content, the earlier topping, the higher accumulation of the nicotine tobacco.4. Proper fertilization will help increase the yield and quality and high-quality fertilizer led to decline production. Topping improve the environment for individual growth, quality and increase the yield and value of tobacco.In summary, with the development of fertilizer level, production is increased significantly, but the trend of quality and value with exorbitant fertilization are at first increased and then decreased in tobacco. Topping would make the photosynthetic products distributed to the tobacco leaf to accumulate dry matter and increase the effective leaf area by block the transmission of assimilation material to the reproductive organs, otherwise, early topping help improving yield and quality of tobacco leaves.