对恩施州植烟土壤微量元素含量状况的统计分析表明,该区域植烟土壤普遍缺硼、锌、铜、氯等微量元素,为了提高烟叶产量和品质,生产上应重视这些微肥的施用;该区域植烟土壤有效钼含量变幅范围较宽,不同生产区域差异较大,施用钼肥应因地制宜;该区域植烟土壤有效态铁、锰含量较高.

Effects of four different boron levels on yield and quality of burley tobacco were studied.Results showed that the agricultural characteristics and appearance quality of3.75-7.50kg /hm 2 treatment were better,while chemical components were coordinated,and smoking quality of burley tobacco was better.The boron application level should be between3.75-7.50kg /hm 2 .

对白肋烟的施氮量、打顶时期、留叶数及收获时期进行了田间试验.结果表明,氮素施用量与烟碱合成呈显著的正相关关系;打顶时期、留叶数和收获时期对烟碱含量高低和氮碱比的影响非常大.实施施氮187.5～225 kg/hm2、盛花打顶、留叶22～24片、打顶后20 d砍收的配套技术措施,可使烟叶烟碱含量适宜、化学成分协调、可用性提高,产量、产值也能达到要求.

研究了白肋烟旺长后生育期间主要化学成分烟碱、总氮、蛋白质、还原糖、钾、镁、钙含量的变化.打顶后是白肋烟烟碱积累最快的时期.7月27日(旺长期)以后大田生长期间,总氮和蛋白质相对含量总趋势持续下降.8月16日(开花打顶)～8月26日(中部叶成熟期)氮碱比由较高(>2)变为协调(1-2).还原糖除开花打顶后到中部叶成熟期略有增加外,总的趋势是减少.旺长以后尤其是成熟期钾含量总的是减少.钙含量则随着烟株生长而增加.镁在旺长以后总的趋势是略增加,到生长后期成熟时增至高峰.同时还针对这些变化,分析了土壤肥料的供给情况,提出了一些降低烟碱的措施.

研究了白肋烟调制期间主要化学成分烟碱、总氮、蛋白质、还原糖、钾、镁、钙含量的变化趋势.晾制开始阶段是烟碱相对含量增加较多的时期,结束前有所减少.晾制期间,总氮和蛋白质相对含量总的趋势是持续下降.氮碱比变为不适宜时期是调制前期,应在这一时期采取措施调节其比值.还原糖含量的变化趋势是变黄期和干筋期迅速减少.晾制期间钾含量略有增加.

The effect of the amount of nitrogen applied on agronomic characteristics,growth stage,yield,value,average price,proportion of superior leaves,physical quality,nicotine content,N/Nic.,and smoking quali ty of burley tobacco were studied.The results showed that high quality burley tobacco could be obtained when the level of nitrogen applied was 12.5～ 15kg/667m2.