Effect Of Nitrogen Application And Remained Leaf Number On Yield And Quality Of Flue-cured Tobacco

The split plot design with two-factorfors, nitrogen fertilizer application and remained leaf number was experimented to study the effects of different treatment on the main agronomic characters, physiological characteristics, yield value and economic traits, appearance characteristics, physical indicators and the intrinsic chemical composition of flue-cured tobacco.1. The plant height, maximum leaf length, maximum leaf width and maximum leaf area of flue-cured tobacco increased with the increase of nitrogen application(90, 120,150kg/hm2). Under the same level of nitrogen application, the effects of remained leaf number on plant height, maximum leaf width, and maximum leaf area of flue-cured tabacco were significant, and these parameters of 20,22treatment were significantly greater than that of 18 treatment. The effects of remained leaf number on maximum leaf length was significant,22 treatment was significantly greater than 18. But effects of interaction on the main agronomic characters of flue-cured tobacco was not significant.2.In the early stage of flue-cured tobacco growth, leaf NR activity and root activity increased with the increase of nitrogen application. In the late stage of flue-cured tobacco growth, under the same level of leaf number, leaf NR activity and root activity increased and then decreased with the increase of nitrogen application. While nitrogen application was on the same level, leaf NR activity of leaf increased and then decreased with the increase of remained leaf number, root activity increased with the increase of remained leaf number.3. Dry matter accumulation and N content of different organs increased with the increase of nitrogen application, P content of leaf and stem, and K content of leaf and root increased and then decreased with the increase of nitrogen application. While nitrogen application was on the same level, dry matter accumulation and P content of leaf and stem increased and then decreased with the increase of nitrogen application, N content of different organs decreased with the increase of remained leaf number, K content of leaf and root increased with the increase of remained leaf number. 4. During maturity stage of tobacco leaf, while remained leaf number was on the same level, the Chlorophyll content, the net photosynthetic rate, transpiration rate, vapor pressure, stomatal conductance of tobacco leaves increased and then decreased with the increase of nitrogen application, intercellular CO2 concentrations discreased with the increase of nitrogen application. While nitrogen application was on the same level, the Chlorophyll content, net photosynthetic rate, transpiration rate, leaf vapor pressure, stomatal conductance of flue-cured tobacco increased and then decreased with the increase of remained leaf number, intercellular CO2 concentrations discreased with the increase of remained leaf number.5. The yield of flue-cured tobacco significantly increased with the increase of nitrogen application,150kg/hm2>120kg/hm2>90kg/hm2; increased and then decreased with the increase of remained leaf number,20>18>22. The output value of flue-cured tobacco increased and then decreased with the increase of nitrogen application and remained leaf number,120 kg/hm2>90kg/hm2 and 150kg/hm2,20>18 and 22. At the same time, interaction effect of nitrogen application and remained leaf number on the yield and output value of flue-cured tobacco were significant.6. As the increase of nitrogen application, N, K, nicotine content of cured leaf increased; Cl, total sugar and reducing sugar content decreased. As the increase of remained leaf number, Cl content of cured leaf increased; K, nicotine, total sugar and reducing sugar cotent decreased. At the same time, interaction effects of nitrogen application and remained leaf number on the content of total sugar and reducing sugar of flue-cured tobacco were significant.