增密减叶减氮模式对烤烟上部叶的提质增香效果

为了提高优质烟叶比例和上部叶工业可用性,于2014年在贵州毕节以常规模式(移栽密度16 530株/hm~2、留叶数22片、施氮量90 kg/hm~2)为对照,设置增密减叶、增密减叶减氮的栽培模式,研究不同栽培模式对烟叶质体色素、香气物质含量及经济性状等的影响。结果表明,增密减叶减氮的栽培措施可促进上部烟叶的成熟落黄,提高上部烟叶的化学成分及香气成分的协调性,对上部烟叶提质增香效果明显。与对照相比,增密减叶减氮处理的烟株生长后期烟叶质体色素降解更为充分;烤后烟叶产值和上中等烟叶比例显著提升;烟叶含氮化合物含量降低,糖含量增加,化学成分协调性增加,香气物质总量显著增加;上部烟叶香气质改善、香气量及甜感增加、刺激性减小。综合分析,移栽密度18 195~20 205株/hm~2、留叶18~20片、减氮20%的栽培模式对上部叶增香提质效果最佳,适宜在毕节地区示范并推广利用。

Effects of Increasing Plant Density and Reducing Leaf Number and Nitrogen Amount on Upper Leaf Quality and Aroma

In order to increase the proportion of quality tobacco and the availability of upper tobacco leaves,the field experiment was set up at Bijie of Guizhou province in 2014 to investigate the effect of different planting model(commonly used model as control with transplanting density of 16 530 plants/ha,22 leaves per plant and nitrogen amount of 90 kg/ha;increasing density and reducing leaf number;increasing density and reducing leaf number and nitrogen amount) on the contents of plastid pigment and aroma components and economic characters of tobacco leaves.Experimental results showed that increasing plant density with less nitrogen fertilization and less leaves promoted leaf maturity and improved the coordination of chemical components and increased aroma quality of upper leaves.Compared with the control group,increasing plant density and reducing leaf number and nitrogen amount gave rise to greater plastid pigment degradation in the late growth stage of tobacco plant;the output value of flue-cured tobacco and the proportion of mediun tobacco increased significantly;the nitrogenous substances reduced,while the contents of sugar and the coordination of chemical composition increased,aroma content increased significantly;the aroma quality of upper leaves was improved with more aroma sweeter feeling and less irritation.Upon comprehensive analysis,the optimal model for improving the quality of upper leaves was 18 195-20 205 plants/ha with 18-20 leaves per plant and 80％ of nitrogen amount of control,which was suitable for further demonstration and application in Bijie of Guizhou.