A field experiment was conducted using two-factor randomized complete block design to investigate the effects of density (D), number of leaves remained (L) and their interaction on photosynthetic characters and economic traits of flue-cured tobacco (cv Yunyan 97). The results showed that D, L and their interaction had significant effects on photosynthetic characters and economic traits of flue-cured tobacco, and the responses from the D were greater than those from L and their interaction. Under same L condition, Pn, Gs, Ci, Tr and chlorophyll content increased first and then declined as D increased. As for the low and medium D conditions, with L increasing, Pn, Gs, Ci, Tr and chlorophyll content increased gradually, but they increased first, and decreased later under high D conditions. In addition, light and CO2 response curve type from all treatments were the same, but response curve parameters were different. With L increasing, maximum Pn rised gradually under low and medium D conditions, while increased first, and decreased later under high conditions. With L increasing, both yield and output value increased significantly under seam D conditions;under seam L conditions, yield rised gradually, but output value increased firstly and then declined, when D increased. On the consideration of comprehensive analysis, effect of 16500/23 treatment was best; and theoretically the appropriate D and L for Yunyan 97 were 17093-17665 plant/ha and 21.3-23.1 leaves/plant respectively.

为了明确陕西省烟叶主产区土壤类型归属,选取了陕西省烟叶适宜种植区中洛南县、陇县、旬阳县3个典型剖面,分别进行了野外观察描述土壤性状和室内测试土壤剖面各层次的基本理化性质.在研究了各取样地土壤形成条件和特点的基础上,按照《中国土壤系统分类检索(第3版)》,鉴定了诊断层和诊断特性,明确了供试土壤剖面在中国土壤系统分类中的归属.检索结果表明,陕西洛南、陇县、旬阳3个烟叶种植基地土壤分别为普通铁质湿润淋溶土、普通钙积干润均腐土、普通简育湿润淋溶土.同时与中国土壤发生分类进行了比较,以便于今后陕西省烟叶种植区对土壤系统分类的推广及利用,并为陕西省烟叶种植基地土壤规划利用和国际间土壤学术交流提供科学依据.

Pot experiments have been carried out to study the effect of external straw application on soil enzyme activities and the nitrogen and potassium contents in tobacco leaves and roots for tobacco variety Qinyan 96. The purpose of this study was to efficiently take advantage of crop waste in order to establish a reasonable resource recycling system and improve the soil environment of tobacco growth. The result shows that external straw addition significantly increased the soil enzyme activity and the nitrogen and potassium contents in tobacco leaves and roots. In a certain range, as the straw usage increased, the soil enzyme activity and the nitrogen and potassium contents in tobacco roots also increased.

A field experiment was conducted to study the effect of different kinds of potassium (K) fertilizers on agronomic attributes, chemical components and economic values of flue-cured tobacco in two typical ecological zones in Shaanxi province. The results showed that K fertilizer had significant effect on leaf area. The effect of potassium nitrate was better than that of potassium humate in Longxian;the effect of potassium humate was the best, followed by mixed k fertilizer. K application increased contents of total sugar, reducing sugar, nitrogen, nicotine and potassium, and decreased the content of chlorine, and these effects varied with ecological zones. Leaf chemical composition was more harmonious with potassium humate or mixed K fertilizer treatment. In addition, main economic values increased significantly with K fertilizer treatment, and better effect was observed with treatment of mixed K fertilizer in Longxian, but potassium humate and mixed K fertilizer in Luonan. Overall, mixed K fertilizer was preferred in Longxian, and potassium humate or mixed K fertilizer in Luonan. K application was useful to optimize leaf chemical components, improved leaf quality and increase yield, but these effects varied with ecological zones.

In order to elucidate the nutrition foundation in plant growth and development and physiological mechanism of leaf color formation by P fertilizer application,and further provide theoretical and practical basis for rational P fertilization in high quality flue-cured tobacco production,pot experiments were carried out to study the effects of different rates of phosphorus fertilizer on leaf nutrition( N,P,K) and polyphenols content as well as their relative enzymes activities of acid phosphates and polyphenol oxidase in flue-cured tobacco leaves using Qinyan 96. The results showed that,in rational range of P application rates from P2O50 to 5. 84 g / pot,N,P,K and polyphenol contents in tobacco leaves were all increased with increasing P rate resulting in significant positive correlations,but the negative effects were obtained due to excessive P rate. Acid phosphatase activity in tobacco leaves was continuously decreased with increasing P rate resulting in significant negative correlations. These results suggested that optimal P application rate could improve leaf nutrition,and increase polyphenols content and its oxidation level to be beneficial for leaf color formation of flue-cured tobacco leaves. Acid phosphates activity can be served as an efficient physiological indictor for evaluation of supply level of soil P.

A field experiment was conducted using split-plot experiment design i.e.three regimes of planting density(D) as main plots and nitrogen(N) rate as sub-plots to investigate the effects of interaction between N application rate and planting density on N and potassium(K) contents,photosynthesis characteristics at round top stage and yield of flue-cured tobacco to determine the optimum N application rate and planting density for better growth,higher yield and quality of flue-cured tobacco. The preliminary results showed that planting density,N rate and the interaction between them had significant effects on the contents of N,K and carbohydrate contents,net photosynthesis rate(Pn) and yield.Significant positive correlations were obtained between N and K contents,Pn,carbohydrate content of flue-cured tobacco at round top stage and yield.Under all three-density conditions,the highest yield and N content presented at high N rate treatment,while the greatest contents of K,Pn and carbohydrate at medium N rate treatment.Under all three N rates conditions,the highest yield and K content presented at medium density,while the greatest N content at low density,and the highest Pn and carbohydrate content at low and medium density.In this study,the best combination of N and density treatment was medium density plus high N rate(D2N3),and the appropriate density and N range were 16 078 ～ 16 698 plant /hm2 and 88.10 ～ 103.19 kg /hm2 respectively for Qinyan 96.

The physical and chemical properties and fertility of three typical tobacco growing soil in Shaanxi Province was studied by measurement of the physical and chemical indexes of soil profile and cultivated soil using principal component analysis method.The results showed that the tested soils belonged to loamy clay with the properties of high bulk density and compaction.relative high pH values(except for optimal level in Luonan),low organic content,relative low nitrogen(N) content(except for optimal level in Luonan),rather low phosphorus(P) content,and relative affluent potassium(K) content.Furthermore,the fertility was affiliated as first,second and third grade in Luonan,Xunyang,and Longxian,respectively.Based on the above results,we suggested that soil amendment agent,organic fertilizer and balanced chemical fertilizer should be applied in the three tobacco-growing areas to improve growth and development,yield and quality of flue-cured tobacco.

To elucidate the best transplanting data of main flue-cured tobacco cultivar K326 in tobacco-growing regions of southern Shaanxi province,an experiment evaluating transplanting date was carried out in Xunyang county.The results showed that with postponement of transplanting date of flue-cured tobacco,all main growth dates were put off;field growth period after transplant became shorter.In addition,contents of nitrogen,potassium,chlorophyll and carbohydrate as well as net photosynthesis rate(Pn) of tobacco leaves at key three growth stages i.e.vigorous growing.topping and mature stages were enhanced firstly and then declines.Yield,average price,output value and percentage of medium and superior tobacco leaves showed the similar laws as the above parameters.Based on comprehensive analysis,May 10 was the best appropriate transplanting date of K326 in Xunyang as a representative location of the same altitude area according to the climatic conditions of this area.To determining the best appropriate transplanting date can improve nitrogen and potassium nutrition and increase photosynthetic efficiency for dry matter accumulation resulting in better yield and quality of flue-cured tobacco leaves.

Pot experiments were conducted using flue-cured tobacco cultivar Qinyan 96 to investigate effect of different mass fraction of sand mixed into clay soil,i.e.S0(control,0%),S1(10%),S2(20%),S3(30%) and S4(40%) on soil physical properties,nitrogen and potassium contents of roots and leaves,photosynthetic characteristics and yields of flue-cured tobacco in Shaanxi Province.The results showed that with the increasing of mass fraction of sand mixed in clay soil,soil bulk density decreased whereas soil porosity increased.The root activity,nitrogen and potassium contents of roots and leaves,net photosynthetic rate(Pn),chlorophyll content,transpiration rate(Tr) and intercellular CO2 concentration(Ci) and yield production all showed the trend of increase firstly and then decrease.The best performance occurred in S3(30%) treatment.From the simulation equation,the optimal mass fraction of sand mixed in clay soil was 23.62% under the current condition.In the range of 0%-30% mass fractions,the mass fraction of sand mixed in clay soil was negatively correlated with soil bulk density while positive with root activity,nitrogen,potassium contents of roots and leaves,leaf photosynthetic characteristics index and yield.As for the range of 30%-40%,the corresponding responses were all negative correlative(except nitrogen contents of roots).Hence,S3(30%) treatment can improve soil physical properties,increase root activity,improve nitrogen and potassium nutrition,and benefit for photosynthetic capacity for high yield of flue-cured tobacco.

To provide a theoretical and practical basis for cultivation of flue-cured tobacco with high yield and better quality,a field experiment was conducted in three different ecological growing-tobacco regions in Shaanxi province.The effects of different types of nitrogen(N)fertilizers and combinations with humic acid(HA)on chemical composition,yield and quality characters of flue-cured tobacco were investigated.Both N fertilizers and combinations with HA increased contents of nicotine and N,but decreased reducing sugar content.Their effects on contents of potassium(K)and chlorine(Cl)were varied due to different ecological conditions.The combined application of N and HA more effectively modulated the content of chemistry components than single N treatment.Yield of tobacco leaves followed the order of LongxianLuonanXunyang,however,the output value showed that Longxian was similar to Xunyang,and both of them were less than Luonan.Both N fertilizers and combinations with HA enhanced yield and quality of flue-cured tobacco in three ecological regions,and their positive effects were different in the three regions.Suitable N fertilizer forms were amide-N in Longxian, but combined-N with ratio of amide∶ammonium∶nitrate 1∶1∶1in Luonan,and nitrate-N in Xunyang.The effects of N fertilizers combined with HA in Longxian and Luonan were greater than that of a single N application,and similar effects were obtained in Xunyang.It is suggested that different suitable N fertilizers should be applied in the various ecological regions,and N fertilizers combined with HA could more effectively promote growth and development,coordinated chemical components of tobacco leaf,and improved yield and quality of flue-cured tobacco than single N fertilizer in these ecological growing-tobacco regions.

A field experiment was conducted to determine the optimum nitrogen(N) application rate and planting density for better growth,higher yield and economic benefit of flue-cured tobacco and to provide scientific basis for production with high yield and quality using Qinyan 96 cultivar in this study.The split-plot experiment design with three regimes of planting density(A) and N rate(B) was applied to study the interaction between nitrogen and density on agronomic characters at round top stage,yield and economic characters of flue-cured tobacco.The results showed that optimal N rate and planting density could improve growth and development,enhance yield and economic benefit of flue-cured tobacco.Regardless of planting density,the best responses recorded under the high and medium N rate.Under the low/high N rate,the best responses recorded under the medium and high planting density while medium N rate under low and medium planting densities.The interaction between N rate and planting density was significant and the responses from the former were greater than those from the latter.System cluster analysis indicated that nine treatments combinations were classified into five ranks,of which best treatment combinations were A2B2 and A2B3,followed by A1B2 and A3B2.On the consideration of comprehensive analysis,the appropriate planting density and nitrogen rate of Qinyan 96 are 16 698 plant/hm2 and N 180 kg/hm2 respectively.Conclusively,to modify N rate and planting density could increase the use efficiency of fertilizer and enhance the yield and quality of flue-cured tobacco based on the interaction between them.

Qinyan96 was developed with G-28 as maternal and Jingyehuang as paternal.Its genetic traits were stability,and the populiation was trim,resistance to drough,and resistance to black shank,medium resistance to brown spot,PVY and bacterial wilt General disease resistance was better than NC89.The cured leaf was well-distributed orange,rich in oil and strong color.It has an appropriate and well-proportioned chemical composition and smoking better quality.Evaluation of leaf quality was better than NC89.According to the results of tobacco varieties regional test in Shaanxi province and the country,tobacco production,average price,proportion of superior tobacco and output value of Qinyan96 were significantly higher than NC90.In conclusion,Qinyan96 is a variety which has better quality,resistance,stable yield,wide adaptability,and it is suitable for planting in Shaanxi,Henan,Shandong,Gansu,and Shanxi etc..

To investigate the matching degree of different flue-cured tobacco cultivars(under the similar ecological condition) leaf quality with tobacco blend grouping of Chinese type cigarette,the comparative study of the main cultivars in China(i.e.Yunyan 85,Yunyan 87 and K326) were carried out in relation to growth,yield,curing and quality characteristics of tobacco leaves based on local standardized production techniques.The results showed that,among the tested three cultivars,the growing period of Yunyan 85 was the shortest,growth vigor of Yunyan 87 and K326 was similar in field,and the yield of Yunyan 87 was the highest.Additionally,chemical compositions of all tested cultivars were basically harmonious,except the relatively high content of nicotine in upper leaf of Yunyan 85 and Yunyan 87.Smoking evaluation results indicated that these three tobacco cultivars had better aroma and less offensive odor,and sweetness of Yunyan 85 was slightly better.

本文介绍了烤烟新品种秦烟95的选育与应用经过,结果表明该品种早熟,大田生育期118 d,较NC 89短1周左右;大田生长速度快,易烤,耐旱性能较好,喜肥水,落黄明显且成熟速度快;烤后烟叶香气量足,杂气略少,灰色多灰白,评吸质量较好;抗CMV和赤星病性能较NC 89稍强,感TMV较NC 89稍差,中抗黑胫病、PVY和根结线虫病;产量、产值和均价多年平均分别较对照品种增加0.05%、7.18%和21.48%,上等烟比率比对照品种高3.49个百分点。此为今后一些烟区烤烟新品种培育提出了有效策略。

介绍了烤烟新品种秦烟2号的主要农艺性状、经济性状、原烟外观质量和内在品质、抗病性及栽培与调制技术.该品种中早熟,大田生育期127d,较K326短5d左右;大田生长势强,早发,施肥不宜过高,落黄明显且成熟速度快;烤后烟叶香气量尚足,评吸质量较好;耐花叶病和抗赤星病、气候斑点病性能较NC89、K326和中烟90强;产量、产值和均价多年平均较对照品种K326分别增加14.47%、24.13%和10.36%,上等烟比率和中等烟比率较对照品种分别高4.25个和3.15个百分点.

按温度因素对陕南气候特点作初步划分,定点选取烟样,分析研究了陕南烟叶质量与气候条件的关系,初步取得了烟叶主要化学成分糖、烟碱、钾及烟叶评吸质量总得分、香气量等与烟叶产区5-8月份平均温度、日较差、降雨、湿度等气候因子的关系.

The tobacco pilled seed bud is the tobacco coating pilled seeds which was revealed and budded by seed strengthen budding technique . The tobacco seeds was treated by osmosis regulator substance such as PEG, sawdust and pearlite, and formed coating pilled seeds at last. The germination perentage, length of radicles, simplify vitality index, tidy degree of the seeds had better improved than common pilled seeds, and the sprouted period was earlier.

通过对烤烟雄性不育杂交种MSA01、MSG01和MSB07的区试和生产示范结果分析,烟叶产量、产值、均价、上等烟比例和单叶重均显著或极显著高于当地主栽品种,原烟品质和对当地主要病害的抗性也均优于对照品种.

研究了将化肥、微生物肥料、螯合态微量元素、有机质、矿物质混合造粒的多元复混肥中特定活体微生物--钾细菌的存活性.该制剂在化肥等无机物含量为70%的高渗条件下,加入钾细菌的活菌回收率达40%～75%;室温条件下保存半年至一年其中钾细菌含量无明显下降.该制剂是一种营养全面、易保存、使用方便、将化肥等无机物与活体微生物融为一体的新型复合肥料.

1试验材料与方法 试验选用烤烟品种NC89;选种方式设水选1h(处理1)、水选4h(处理2)、风选(处理3)和对照不选种子(处理4)4个处理.每处理用2kg种子选种,选种结束后种子自然充分晾干,计算千粒重,并在衡温衡湿培养箱(25.5℃)做发芽试验,重复3次;同时对其余种子进行包衣丸化处理后进行田间育苗试验,苗床小区面积1m×2m,重复3次,随机区组排列.