The relationship between appearance character and internal quality of flue-cured tobacco was studied with 150 leaf samples produced in 2007 in Henan Province.The relationship between appearance character and smoking quality showed that there were poor smoking quality tobacco leaf samples among different stalk positions and among different bands on the seven appearance quality factors.There were significant correlations between smoking quality and each of the following: stalk position,color,body,and leaf structure.Overall,the smoking quality of the upper leaves were poor,the smoking quality of the deep orange leaves were poor,the smoking quality of the fleshy body leaves were poor,and the smoking quality of the still loose leaf structure leaves and the firm leaf structure leaves were poor.There were no significant correlations between maturity,oil,color intensity,length and the smoking quality.The relationship between appearance character and chemical components showed that there was no close relation of maturity,length and main chemical components or their derived values.

We randomly selected 146 flue-cured tobacco samples from 9 provinces in China and 40 abroad to determine the alkaloid contents of flue-cured tobacco leaves by gas chromatography,and its variation pattern,geographical distribution and correlation were analyzed.The results showed that for domestic samples,the alkaloid content variation were wider than that abroad,the contents of total alkaloid and nicotine were high,while the nornicotine,the myosmine,the anabasine and the anatabine alkaloids were low,the alkaloids were ranked from high to low as nicotine,anatabine,nornicotine,anabasine and myosmine.There was a positive correlation among nicotine,nornicotine,myosmine,anabasine and anatabine.There exsisted highly significant difference in alkaloid contents among different leaf positions,which ranked from high to low as B2F,C3F and X2F.In terms of nicotine conversion rates,grades were ranked from high to low as B2F,C3F and X2F.There was highly significant difference in nicotine content and nicotine conversion rates among tobacco leaves from nine provinces.The total alkaloid content were ranked from high to low as Guangxi,Fujian,Hunan,Shandong,Guizhou,Liaoning,Yunnan,Henan and Sichuan,while the Anatabine,nornicotine,anabasine and myosmine;nicotine conversion rates were ranked as Sichuan,Henan,Liaoning,Yunnan,Guizhou,Hunan,Shandong,Fujian,Guangxi.There was a significant correlation between alkaloid content and sensory quality,and nicotine had largest influence on sensory quality,while there were significant negative correlations between nicotine and aroma,after taste,offensive odor,irritancy.But nicotine conversion rates had no significant correlation with sensory quality.There was a significant negative correlation between alkaloid and composite quality.There was no significant correlation between nicotine conversation and composite quality.

In order to find out the difference in chemical composition between tobacco with different flavor types and their effects on smoking quality,106 fluecured tobacco samples from west Fujian and middle Jiangxi were analyzed and their smoking quality and flavor style were identified.The results showed that the contents of nicotine and total nitrogen in tobacco with dominant flavor type in west Fujian and middle Jiangxi were far lower,while the contents of reducing sugar and total sugar,the ratios of sugar to nicotine and nitrogen to nicotine were far higher than those in non-dominant flavor type tobacco.The closer the flavor type to fresh aroma note,the lower the contents of nicotine and total nitrogen and the higher the contents of reducing sugar and total sugar would be.The ratio of sugar to nicotine was the most important factor affecting the flavor quality of tobacco leaf,nicotine content was the major factor,and the ratio of nitrogen to nicotine the next,which affected flavor quantity,offensive taste,aftertaste,irritation,strength and smoking quality of tobacco.The nicotine content was the major factor,and ratio of sugar to nicotine the next,characterizing the typical fresh flavor style of tobacco.Therefore,in west Fujian and middle Jiangxi tobacco growing area,nicotine content is an essential factor affecting smoking quality of flue-cured tobacco,and the ratios of sugar to nicotine and nitrogen to nicotine are also important influence factors.

We collected 150 leaf samples of flue-cured tobacco from five counties in Henan Province and tested their major chemical components and smoking quality. The results showed the odor types of Henan flue-cured tobacco were full-bodied, but some of them were no longer typical. The odor type of flue-cured tobacco in Pingdingshan and Zhumadian were more typical. There were close relationships between the nicotine contents, the ratio of total nitrogen contents to the nicotine, the ratio of the total sugar contents to the nicotine and the sulphur contents. The statistical results showed that there were significant negative correlation between the nicotine contents, total nitrogen contents, the ratio of the reducing sugar contents to total sugar and the smoking quality, significant positive correlation between the total sugar contents, the reducing sugar contents, the ratio of the total sugar contents to nicotine and the smoking quality within the specific limits, and all of their correlation were significant at 1% level. The chemical components suitable ranges were discussed when their odor type were more typical and had upper smoking quality.

Results of two years pot experiments showed that plantation of green manure increased the content of organic matters in soil and greatly improved microbial activities and functional diversity.Application of calcium fertilizer significantly improved growth of flue-cured tobacco and increased dry weight of tobacco leaf by 6.1 times.Compared with applying inorganic fertilizers only,combined application of chicken manure and inorganic fertilizers further increased dry weight of tobacco leaf by 24.2 times.Combined application of chicken manure and calcium fertilizer increased uptake of nutrients.Under condition of combined application of chicken manure and inorganic fertilizers,application of calcium fertilizer significantly increased the uptake of Ca and Mg but greatly decreased uptake of P,K,B,and Mn.Therefore,the plantation of green manure and application of good-quality chicken manure will be beneficial to both quality and yield of leaf tobacco.

2004年在我国西南地区的新垦红壤山地建立了烟草基地,该基地的地理位置是N 26°28′～29′,E101°51′～53′,开发总面积约为267 hm2.2005年和2006年连续两年基地的烤烟都出现了大面积的烟叶呈‘倒勺子状'翻卷的症状,初步诊断是生理缺钙所致[1～3].已有研究[2,3 ]从田间考察、对土壤和有机肥的检测、病株的组织分析以及水培试验等证明该症状是由于使用了一种含有过量磷酸根、硫酸根等阴离子的商品有机肥1号(是某肥料厂专门为该基地生产的一批有机肥)所诱发的,其机理是过量的磷酸根和硫酸根与根际土壤中本来就不富裕的有效钙反应形成磷酸钙沉淀和难溶性的硫酸钙,使烟株难以吸收足够的钙而诱发缺钙症状,同时烟草植株吸收了过量的磷酸根和硫酸根,使体内已经吸收的钙的转运受阻或再利用困难,加剧了缺钙症状的发生[4～7].

通过对攀枝花地区气象条件和烤烟生产情况分析,认为该地区特别是半干旱的山区可以通过发展雨水集蓄利用技术,采取适当推迟移栽的生产方式,解决当地烤烟常规移栽时严重缺水导致的烟苗前期生长不良、发育不全、烟叶产低质次的问题。研究表明:选择在径流汇集的部位就地修建敞口的蓄水池,以便同时收集雨水和径流,提高水资源的截留量,在旱季(10月底至翌年5月初)进行薄膜覆盖,可以减少池内储水蒸发损失达35%以上。大田试验研究表明:推迟到6月初移栽,可促进烤烟前期根系生长,不仅生长量明显比常规移栽要大,全生育期仅比常规的推后7d左右,而且也不影响烟叶的采收和烘烤。

Tissue analysis of flue-cured tobacco plants with different degrees of calcium deficiency sampled from the tobacco production base located in Southwest China show that the symptom of calcium deficiency on tobacco plants was mitigated with increasing Ca concentration in the leaves,but aggravated with increasing SO2-4 and PO3-4 concentrations in the leaves.Results of the hydroponic experiment indicated that high PO3-4 concentration in the solution could induce symptom of calcium deficiency on tobacco plants.The greater the PO3-4 concentration in the solution,the earlier the occurrence of the symptom,and the more serious the symptom.These findings revealed that serious calcium deficiency of tobacco plants in the production base resulted from application of the commercial organic manure containing high concentrations of SO2-4 and PO3-4,which reduced solubility of Ca in the rhizosphere,thus hindering uptake and transport of Ca2+ by the plants.

烤烟是我国重要的经济作物,2006年全国种植烤烟的面积达114.5万hm2,总产量为2 163 t[1].烤烟生产分布在全国23省市,是2 000多万农户、约一亿多烟农主要的经济来源[2].特别是在我国经济尚欠发达的西南地区,烟叶生产是重要的支柱产业之一.