断根对延边烤烟根系生长和烟叶糖、烟碱及钾含量的影响

延边烤烟存在烟叶糖含量偏高，烟碱含量较低的生产现状，通过田间试验以吉烟9号为试验材料，比较了不同断根措施对烤烟根系生长及烟叶糖、烟碱和钾含量的影响。结果表明，断根能明显促进烟株根系的生长，提高烟株生长后期根系活力，增加烟株对营养的吸收能力。断根降低了上、下部烟叶的糖含量，提高了烟叶烟碱含量，增加了中、上部烟叶钾含量，且化学成分更加协调。总的来看，团棵期轻度断根处理的烟株生长后期根系活力显著高于其他处理，显著提高了烟叶烟碱、钾含量，适度降低了烟叶糖含量，烟叶糖碱比更加协调，进而提高了烟叶的内在品质。

Effect of Root Cutting on Root Growth and Sugar,Nicotine, and K Contents of Yanbian Flue-cured Tobacco

Currently, high sugar and low nicotine contents in flue-cured tobacco leaves in Yanbian area had resulted in some problems. A field experiment with the Jiyan 9 was carried out to investigate the effects of various root cutting treatments on tobacco root growth and leaf sugar, nicotine, potassium content. The results showed that root cutting obviously promoted the tobacco root growth, improved root activity at later growth stage of tobacco, and also increased the uptake of the nutrition of tobacco. Root pruning reduced sugar of tobacco leaves, improved the nicotine content, and increased the K content of middle and upper leaves, and harmonized the chemical components. In general, through the rosette stage light root pruning, root activity was significantly higher than other treatments in later growth stage, and increased the nicotine and potassium content, and reduced sugar content of tobacco leaf appropriately, and the ratio of sugar and nicotine was more coordinaed, which improved the internal quality of tobacco leaves.