中文摘要：

针对陇东烤烟主要品质中钾含量偏低和烟碱含量过高的问题,于2008年在庆阳市正宁县布置大田试验,研究了打顶后涂抹7种不同外源激素对烟叶钾和烟碱含量及产量、产值的影响。结果表明,打顶明显降低了烟叶含钾量,提高了烟碱含量;而打顶后涂抹7种外源激素均能提高烟叶含钾量,降低烟碱含量,但7种外源激素效果明显不同,其中以GA效果最好,与打顶相比,GA使上、中和下部叶钾含量分别提高了42.2%、46.5%和56.4%,烟叶含钾量达到3%以上,中上部和下部烟叶烟碱含量分别下降到最佳值2.5%和1.8%左右;2,4-D效果最差。打顶后涂抹7种外源激素可以显著提高烟叶产量、均价、中上等烟比例和产值,以GA、CTK和CEPA效果较好;而打顶后涂抹2,4-D使烤烟产量、均价和产值比打顶均有一定程度的下降。由此可见,选择合适的外源激素能够解决陇东烤烟钾含量低和烟碱含量高的问题,可以大大提高陇东烤烟的品质、产量和产值。

英文摘要：

Low potassium （K） and high nicotine content of tobacco have restricted the development of tobacco pro- duction in East Gansu. Based on a field experiment, the effects of seven kinds of exogenous hormones after topping on the contents of potassium and nicotine in tobacco were studied in Zhengning of Qingyang in Gansu Province. The result showed that topping decreased K content and increased nicotine content significantly, and daubing seven kinds of exoge- nous hormones after topping could increase K content and decrease nicotine content obviously. Moreover, seven kinds of exogenous hormones had different effects on K and nicotine content. Compared with topping, GA had the best effect, which increased K content by 42.2 %, 46.5 % and 56.4 % in upper, middle and lower leavers respectively and made it up to over 3 % , and the content of nicotine deceased to optimum value （2.5 % in upper and middle leavers and 1.8 % in lower leavers）, The effect of 2, 4 - D was less effective. Daubing seven kinds of exogenous hormones after topping could increase yield, average price, ratio of mid-high grade leaves and output value of tobacco, and GA, CTK and CEPA bad better effect, while 2, 4 - D slightly decreased yield, average price, ratio of mid-high grade leaves and output value of tobacco. This indicated that suitable exogenous hormones could achieve high potassium and low nicotine content, resulting in the improvement of quality, yield and output value of flue-cured tobacco in East Gansu.