The Effect Of N Management On The Law Of Carbon And Nitrogen Metabolism And Yield And Quality Of Flue-cured Tobacco

In this paper, through the study of how N management influence the law of carbon and nitrogen metabolism and quality of flue-cured tobacco in Zhaowei Yuxi Yunnan, discuss the effect of different N management on the growth of tobacco, the content of nitrogen, phosphorus, potassium in root, stem, leaf and the content of nicotine in leaf, the impact of the activities of key enzymes of carbon and nitrogen metabolism and chlorophyll content, the chemical composition of flue-cured tobacco and economic traits. The main results are as follows:1With increasing amount of nitrogen in the case of phosphorus, potassium quantitative, plantheight, maximum leaf length, leaf width, leaf area index increased; N management have a great influence on the plant height, leaf area index, less affected on the stem girth and maximum leaf length, leaf width.2Nitrate reductase activity increased first and then decrease; N management have a great influence on converting enzyme activity during the early growth period and the effects is small in late stage of growth; the NO,N1processing activity showed a gradually increasing trend of nitrogen, the N2,N3processing present a bimodal curved shape, the N4,N5processing activity reduced and then increased in the late, each treatments amylase activity keep the high level in the latter part; the NO,N1,N2processing chlorophyll content reaches the maximum time is earlier, the chlorophyll content of N4,N5processing reaches its maximum value in its fast growing period, the latter remained at a high level; Chlorophyll content and SPAD value changes of the same.3N management impact on nicotine content is mainly in the early stage of growth stage. Leaf nitrogen, phosphorus, potassium content is the highest, stem total nitrogen content is higher than root in growth prophase, lower than root in the late growth stage, stem phosphorus, potassium content were higher than the root system. N management effect on the nitrogen of leaf and root throughout the growing period, impact on the content of phosphorus, potassium in leaf, stem and root is in the growth stage, late effect weakened. Leaf potassium content change rules same with the root and stem variation.4With the increase of nitrogen application rate, the total sugar, reducing sugar content increased before they are reduced, N management effect on the lower and middle leaves total sugar, reducing sugar content in the larger, less effect on the sugar content in upper leaves. Sucrose content increases with the increase of nitrogen application rate, the content of fructose and glucose were gradually reduced. N application significantly influence on nicotine and total nitrogen content, N management have a less influence on the two sugars and nitrogen to nicotine ratio, impact on sugar to nicotine ratio than larger; the N1,N2treatment effect on sugar to nitrogen ratio is small, the N4,N5treatment effect is big, this is associated with increasing nitrogen application rate, total sugar, reducing sugar content were reduced, but the total nitrogen and nicotine content were increased.5From the tobacco total sugar, reducing sugar, total nitrogen, nicotine, sugar to nicotine ratio, the difference between the two sugars, sugar nitrogen ratio, nitrogen to nicotine ratio indicators and economic traits, we view that nitrogen application7kg/667m2can got chemical composition of coordination, win-win economic and quality benefits of high-quality tobacco raw materials.