Effects Of Planting Density And Nitrogen Application On Production On Growth And Quality Of Flue-cured Tobacco From Different Areas In Chongqing

Research of different planting density and nitrogen application under different altitude was done in 2012 to illuminate the effects of planting density and nitrogen application on growth, production and quality, and improve quality and industry usability of tobacco leaves. And another research on effects of different planting density and interaction effects of nitrogen application on growth, main chemical indices, production and quality was conducted in 2013. Instructive results were as follows:1 Results of planting density and nitrogen application in different altitudes in 2012 indicated that, a significant influence was noticed on economic traits of tobacco in planting density under different altitudes, mainly in output value and upper leaves; the best of which was from altitude 1000m and density 1100 per 667m2. Significant effects were also found in economic traits of nitrogen application under different altitude, mainly in output value and production; Altitude 1000m and nitrogen application 9kg per 667 m2 was the best.2 Results of growth under different planting density and nitrogen application and field microclimate indicated that, significant influences were both noticed on field agronomic traits under different planting density and nitrogen application.Thus, plant height was the highest when the planting density was 1100 and nitrogen application 9kg per 667m2, and Wushan and Youyang were 110.72cm and 109.73cm respectively.Planting density, nitrogen application and leaf position and their interaction effects had significant influence on Photosynthetic rate. Leaf position also highly affected intercellular CO2 concentration and transpiration rate. However, planting density, nitrogen application and leaf position had little effect on stomatal conductance of tobacco leaves. Photosynthetic rate of each position can be promoted by increasing nitrogen application and decreasing planting density, the highest of which was those in high nitrogen application, low planting density and upper leaves (21.24?mol·m-2·s-2).The respiration rate in one plant was distributed as upper leaves> middle leaves> lower leaves, while intercellular CO2 concentration is upper leaves< middle leaves< lower leaves. In the late stage of maturity, planting density and nitrogen application had little effect on light and effective radiation of upper leaves, but affected a lot on middle and lower leaves. Nitrogen application was the main factor in affecting effective photosynthetic rate, which performed as low nitrogen application> middle nitrogen application> high nitrogen application; Vertical temperature of each position dropped obviously with the increasing of nitrogen application in the same density of planting, while planting density did not significantly affect vertical temperature of plant.It was also indicated in this study that, there was a significant Positive correlation between height, stem girth, the biggest length and width of leaf and photosynthetic rate; a significant positive correlation between height, stem girth and effective photosynthetic radiation; and a highly negative correlation between height and vertical temperature.3 Results of main chemical components, production and quality under different planting density and nitrogen application in 2013 indicated that, planting density, nitrogen application and leaf position and their interaction effects had significant impacts on the content of total sugar, reducing sugar, starch, total nitrogen, nicotine and protein. Few influence on the content of potassium and chlorine. A general rule was found in middle and upper leaves that, the content of carbon metabolism indices like total sugar, reducing sugar and starch, increased with the reducing of planting density and nitrogen application, performed a significantly positive interaction effects. The content of nitrogen metabolism indices like total nitrogen, nicotine and protein, increased with the reducing of planting density and increasing of nitrogen application, performed asignificantly negative interaction effects. Planting density and nitrogen application had significant influence on economic traits. Production, output value, average price and proportion of first-class tobacco increased with the increasing of nitrogen application in the same planting density. Production and proportion of first-class tobacco increased significantly with the increasing of density in the same nitrogen application. While output value and proportion of middle-class tobacco increased first and then decreased with the increasing of planting density. Results including output value and production of flue-cured tobacco leaves were the best when nitrogen application was 9kg per 667m2 and planting density was 1200 per 667m2.