钾肥追施时期对山地烤烟烟叶质量的影响

为提高钾肥利用率,增加山地烤烟钾含量及其中性致香物质含量,采用田间试验的方法,进行不同时期追施钾肥试验,比较各生育期土壤钾含量及烤后烟叶化学成分、中性致香物质和感官评吸质量。结果表明:土壤中全钾及速效钾含量变化基本一致,均随追施K_2SO_4的时间而相应变化;随着钾肥追施时间的后移,烤烟中上部烟叶钾含量、中性致香物质含量等均有所提高,以移栽后40d追施硫酸钾20kg/667m^2的效果最好,烤后中部烟叶评吸得分最高,中性致香物质总量分别比不追施钾肥、移栽后20d和30d追施钾肥分别高27.49%、22.13%和14.01%。

采收时期对烤烟成熟度和感官质量的影响

为探究不同采收时间对烤烟产质量的影响,以云烟87为试验材料,通过大田试验,设置3个采收时间处理。结果表明:下部叶推迟2d采收,中部叶推迟3d采收,上部叶推迟4d采收对烤烟产质量影响最大,可有效降低烤后烟叶总糖、糖碱比以及氮碱比;可显著提高中部叶中性香气物质成分类胡萝卜素降解产物类、类西柏烷降解产物类、棕色化反应产物类、新植二烯含量,其中提高幅度分别为18.02%、17.73%、7.82%、9.85%;烤后烟叶成熟度好,油分足,结构疏松,烟叶充分成熟无青杂烟出现,产量与均价均有所增加。因此,通过适当推迟采收可以提高烟叶成熟度,协调烤烟内部化学成分含量,为优质烟叶的生产提供技术支撑。

沼肥在白肋烟生产上的应用

白肋烟施用沼肥后产量、产值、上等烟率均有提高的趋势。施沼液的处理和既施沼渣又施沼液的处理使烟叶产量增加幅度均超过6％以上，亩产值均增加100元以上，施沼渣的处理亩产值增加了70元；施沼液、既施沼渣又施沼液、施沼渣三处理的上等烟率分别提高5．9，7．8，9．7个百分点；施沼液的处理成熟期烟叶（整株）烟碱含量与对照相比下降了0．69个百分点；与对照相比，施沼渣沼液处理和施沼渣处理的烟叶香气物质含量显著增加，其21种主要香气物质的总量增加了55．5％-105．3％，新植二烯增加了57．5％-109．3％，二氢猕猴桃内酯、吲哚、醇类总量、巨豆三烯酮、吡啶类总量、吡嗪类总量均有不同程度增加，但醛类总量、酮类总量略有下降或持平；烟叶的香气质、香气量得到较大改善。施沼液处理的中部叶和施沼渣又施沼液处理的中部叶的香气质评价均由“中等…档次提高到较好档次。

Judgment of Aroma Types of Middle and Upper Flue-cured Tobacco Leaves Based on Stepwise Discriminant Analysis

[Objective] The aim of this study was to establish mathematical models for judging the aroma types of middle and upper flue-cured tobacco leaves according to the contents and proportions of aroma compositions. [Method] The aroma types of tobacco leaves were judged based on stepwise discriminant analysis, using 63 C3F and 65 B2F tobacco leaf samples from 13 tobacco producing regions in 11 provinces of China （Huili in Sichuan, Baokang in Hubei, Wulong in Chongqing, Lu- oyang in Henan, Zhucheng in Shandong, Wuyi Mountain in Fujian, Malong in Yun- nan, Chuxiong in Yunnan, Bijie in Guizhou, Liuyang in Hunan, Suiyang in Guizhou, Kaiyuan in Liaoning, Nanxiong in Guangdong） as calibration samples, and 67 aroma components as indices. And the Fisher discriminant functions were verified using 21 C3F and 19 B2F tobacco leaf samples. [Result] Variation coefficients of the propor- tions were lower than that of contents of most aroma components in middle and upper leaves of the samples, indicating that the proportions were more stable than contents of aroma components. The proportions of benzyl alcohol, solanone, β-dam- ascone, neophytadiene, farnesylacetone A, palmitic acid, thunbergol, methyl linole- nate and cembratriene-diol were all over 1% in both middle and upper leaves, al- though the dominant aroma components of the same aroma type varied between middle and upper leaves. Moreover, 11, 18, 7 and 11 aroma components were re- spectively introduced into the Fisher discriminant functions established based on the contents and proportions of middle and upper flue-cured tobacco leaves, which ex- hibited accuracy rates of 91.7%, 100%, 91.7% and 91.7% in the judgments of other tobacco leaf samples. The results revealed that the components those determined aroma types in middle leaves were obviously more than in upper leaves. In middle leaves, the accuracy rates of aroma type judgment could be improved by using the proportions rather than the contents of aroma components as indices. However, the functions based on the proportions and the contents of aroma components in upper leaves gave close accuracy rates. [Conclusion] The results of the study will provide references for identifying aroma types of flue-cured tobacco leaves in future work.