不同鲜烟叶田间优化数量对烤烟生理特性及经济性状的影响

为了明确重庆烟区不同鲜烟叶处理技术对烤烟光合生理特性、产量、等级结构及经济性状的影响，本研究选用云烟97品种，研究4种下部不同烟叶摘除数量（0、2、3和4片）对烤烟根系活力和下、中、上3部位叶片叶绿素含量及生理特性的影响。结果表明，摘除下部不同烟叶能显著提升烟株根系活力、增加叶绿素含量、提高净光合速率（Pn）和蒸腾速率（Tr）、延缓光合功能衰退，这种作用随摘除叶片数量的增加而增强，且下部叶受到的影响最大，其次为中部叶，上部叶最小。摘除不同烟叶后，前期（10天）叶片的WUE随摘除数量的增加而提高，中后期（24和38天）摘除数量越多WUE越小。就产量而言，摘除下部叶片越多，产量越低；摘除叶片后对等级结构和经济效益都不同程度的提高，其中以T2处理最为显著，其次是T1处理，T3 处理的效果最差。因此，在武隆生态条件下的中等肥力土壤上处理下部鲜烟叶时，以打掉3片为宜。 

Effects of Number of Removing the Fresh Leaf on Physiological Characteristics and Economic Characters of Flue-cured Tobacco

The objectives of this study were to investigate the effects of the number of removing the fresh Leaf on physiological characteristics, yield, hierarchical structure and economic benefit of flue-cured tobacco. A field experiment was carried out to study the effects of four numbers of removing field fresh leaf (0, 2, 3, and 4) on root vigor, and Leaf Chlorophyll content and photosynthetic characteristics of the leaves in three positions (leaf 5, 10, 16 from bottom to top) of flue-cured tobacco Yunyan 97. The results indicated that with the increase of number of removing the fresh leaf, the root vigor was increased, the chlorophyll content was enhanced, the decline net photosynthetic rate (Pn) was reduced, the transpiration rate (Tr) increased, photosynthetic function decline was delayed. The highest influence was found on lower leaf, followed by the middle leaf, whereas the lowest was observed with upper leaf. At an earlier stage (10 d), with the increase of number of removing the fresh leaf，the WUE of the leaf increased, and the WUE of the leaf decreased with the increase of number of removing the fresh leaf in mid-term and later period (24 and 38 d). For tobacco yield, the yield reduced along with increasing of the number of removing the fresh Leaf. The economic benefit and hierarchical structure of flue-cured tobacco were improved in different degree by removing the fresh leaf. The highest improvement was found on the T2, followed by the T1, whereas the lowest was observed on T3. Therefore, when removing the fresh leaf on moderate fertility soil in Wulong ecological conditions, the fitting number of removing was three.