Caiyin FAN，Liang ZHAN，Zhi LlN，Huiyu ZENG，Jianhua Ll，Yongqiu HE，Diqin Ll

1.Changning Tobacco Branch，HengYang CompanY，Changning 421500，China；

2.Hunan Agricultural UniversitY，Changsha 410128，China

Effects of Warming Seedling Cultivation Technology on Growth，Yield and Quality of Fluecured Tobaccos

Caiyin FAN1，Liang ZHAN1，Zhi LlN1，Huiyu ZENG1，Jianhua Ll1，Yongqiu HE1，Diqin Ll2*

1.Changning Tobacco Branch，HengYang CompanY，Changning 421500，China；

2.Hunan Agricultural UniversitY，Changsha 410128，China

An experiment of seedling nursing which used film mulching technologY in greenhouse to increase temperature was carried out in the south of Hunan province in 2014.The results showed that the average surface temperature of seedling traY and the average water temperature of nursing pool at 10:00 and 16:00 in treatment 1 which used film mulching technologY in a greenhouse were higher than that of CK （no film mulching），suggesting the warming effect of mulching film in a greenhouse is obvious.The growth potential of tobacco seedling is stronger in treatment 1 than CK，and tobacco seedling qualitY index including the fresh and drY weight of stem，leaves and roots increased.Plant height，stem girth and leaves area of the treatment 1 were higher and more than that of CK after transplanting.Squaring，topping and maturitY period were slightlY earlier in the treatment 1，compared with that of CK.Average Yield of treatment 1 was 2 308.8 kg/hm2，which increased bY 6.03%and was significantlY higher than that of CK，and the output value of the treatment 1 was 50 184.75 Yuan/hm2，which increased bY 5.61%.

Flue-cured tobacco；Seedling cultivation；Shed with Nulches in a greenhouse；Yield and qualitY

C uring of tobacco is an important chain of field production of tobaccos［1］.With an appropriate seedling cultivation time and a goodenvironment，theemergence rate would be higher，and seedlings would grow healthY.lt is well known that to obtain highlY-efficient，highlY-qualified，low-cost and Yielding tobaccos is on the premise of cultivating strong seedlings［2-5］.However，there is the problem of low temperature and less sunshine in earlY stage of fluecured tobacco in tobacco fields in Changning，which exists for so manY Years.ConsequentlY，the tobaccos perform poorlY in resistance，and seedling cultivation term lasts too long. ln middle term，rains become frequentlY and sunnY daYs are few.ln later term，tobacco seedlings grow slowlY due to high temperature and drought，resulting in viral disease and bacterial wilt，which affects tobacco qualitY and Yield.The research，therefore，conducted warming-based tests with mulches in a greenhouse in order to explore measures for cultivating seedlings and provide references for cultivating strong seedlings and improving seedling qualitY and tolerance in tobacco fields as per crop rotation.

Materials and Methods

Test sites

The test was carried out in a tobaccocultivationfactorY（112°27′30.42″E and 26°22′15.65″N）in Sanjiaotang Town，Changning CitY.SpecificallY，tobacco seedlings were cultivated with mulches in a greenhouse bY floating nursing.The test soils were graY paddY，with moderate fertilitY.

Test variety

The test varieties included K 326 which was sown on December 22，2013 and transplanted on Narch 9，2014.

Test design

The test designed two treatments in one greenhouse.SpecificallY，treatment 1 （T1）involved mulches and treatment 2 （T2）was a control group without mulches.ln the greenhouse，6 neighboring nursing pools were selected and everY treatment contained three replications.However，water depth and nutrient solution concentration kept the same.After the seedlings were transplanted into tobacco fields，the two treatments above were designed with three replications as per randomized block design.EverY test plot was 60 m2and the planting densitY was 1.2 m×0.50 m.Besides，guarding rows were prepared around test plots. Tobacco fields were management as per local method.

To observe recording items

TemPeratures of trays and nursing Poolss After sowing，temperatures of seedling traYs should be recorded.lt is notable that the end part of a thermometer should be 5 cm awaY from surface of seedling traYs before sowing and 5 cm awaY from growing point after germination. The recording should be twice at 10:00 and 16:00 everY daY.

Research on seedling quality For everY treatment，20 seedlings were randomlY selected from 10 d（FebruarY 28）and 1 d （Narch 8）before transplanting in order to explore seedling height，the number of leaf，stem diameter，fresh weights and drY weights of a plant，of stem and leaf，and of roots. lt is notable that for drY weight，fresh plants should be killed out at 105℃for 20 min，followed bY firing at 60℃. FinallY，the plants were weighed after the temperature cooled to room temperature to compute fresh weight-todrY weight ratio.

The growth duration after trans-Planting After transplanting，recording on growth duration should be started.

Major economic characters and indices When grew mature，tobaccos were harvested and cured to compute Yield.Besides，output value was computed according to average price of that Year and the tobaccos were graded to calculate grade ratio.

The analYsisofvariance was conducted on the test data with DPS and LSD.

Table 1 Accumulated temperatures and average temperature at 10:00 and 16:00 of treatments in different growth stages

Table 2 Growth stage of tobacco seedlings in different treatments

Results and Analysis

Accumulated temPeratures of water and trays in different treatments and growth stages

As shown in Table 1，mean accumulated temperatures of water at 10:00 and 16:00 in T1 were 0.1℃and 0.7℃higher compared with T2 and of seedling traYs were 0.8 and 0.6℃higher.lt can be concluded that the treatment with mulches in a greenhouse performed better.

Growth term and quality index of tobacco seedlings in different treatments

As shown in Table 3，little cross stage and big cross stage of T1 were 1 and 2 d earlier compared with T2，and the rest stages showed insignificant differences.These indicated that the treatment with mulches in a greenhouse would promote tobacco growth during cross stages.

As shown in Table 4，plant height，stem diameter，fresh weight and drY weight of a plant，fresh weight and drY weight of stem，leaf and roots all kept higher in T1，compared with T2，10 d before transplanting.One daY before transplanting，the number of leaf，stem diameter，fresh weight and drY weight of a plant，fresh weight and drY weight of stem，leaf and roots of T1 all kept higher.These indicated that the treatment with mulches in a greenhouse would improve tobacco seedling qualitY.

Growth stage of tobacco fields in different treatments

As shown in Table 5，of T1，after tobacco seedlings were transplanted to tobacco fields，the maturitY stage，squaring stage，topping stage of different parts all proved 1 d ahead of schedule.

ltcan be concluded thatthe treatment with mulches in a greenhouse advanced tobacco growth，harvesting and curing in tobacco fields.

Major agronomic trait index in different treatments

As shown in Table 6，plant heights in rosette stage and harvesting stage of T1 were higher compared with T2，but none significant differences were shown.Besides，stem diameter of T1 during Rosette stage and harvesting stage were higher；internode distance during harvesting stage of T1 was higher；the number of effective leaf of T1 was higher；average leaf area index（LAl）of T1 was also higher；the length and width of waist-part leaf were both higher of T1.

ltcan be concluded thatthe treatment with mulches in a greenhouse would advance seedling growth after transplanting，increase plant height，stem girth and internode distance，and extend photosYnthesis area to promote waist-part leaf growth and improve tobacco Yield.

Major economic characteristics index of different treatments

As shown in Table 7，both of Yield and output value of T1 were higher compared with T2，though with insignificant differences.Besides，the proportion of moderate and high-grade tobaccos of T1 kept higher compared with T2，but showed little differences.

Therefore，it can be concluded that the treatment with mulches in a greenhouse improves proportion ofhigh-grade tobaccos and tobacco qualitY，so that economic benefits of tobaccos can be enhanced，which is of practical significance for tobacco production.

Table 3 Seedling qualitY index of different treatments

Table 4 Growth stages of different treatments

Table 5 Agronomic trait indices of different treatments

Table 6 Yield，output value，average price，and proportion of tobaccos at different grades

Discussions and Conclusions

Effects of the treatment with mulches in a greenhouse on tobacco seedling quality

According to researches available，floating nursing method with mulches in a greenhouse is an effective measure to prevent adverse effects of low temperature in the south of China，which improves temperatures in a greenhouse and temperatures of nursing poolss for seedling cultivation，so that seedling growth can be guaranteed at a proper temperature［1，3-4］. The research also proved that the treatment with mulches in a greenhouse does increase temperatures in the greenhouse and temperatures of water，promoting seedling growth.Besides，little cross stage and big cross stage proved 2 and 1 d in advance. Neanwhile，the treatment improved tobacco qualitY and enhanced fresh and drY weights of stem，leaf and roots.

Effects of different treatments on tobacco growth，yield and quality

Researches available incorporate that the treatment with mulches in a greenhouse improves qualitY of tobacco seedling，so that the survival rate would be improved after transplanting，which is conductive to increasing of tobacco economic characteristic indices［1，3-4］.The research has demonstrated that squaring stage，topping stage and mature stage were all earlier in the treatment with mulches in a greenhouse.Furthermore，major agronomic trait characteristics indices all grew，covering the number of leaf，average leaf area，LAl，internode distance，and length and width of middlepart leaves，laYing foundation for enhancing proportion and Yield of highgrade tobaccos.The research suggested that tobacco Yield reached 2 308.8 kg/hm2in the treatment with mulches in a greenhouse，increasing bY 6.03% （131.4 kg/hm2）compared with the control，and the output value averaged 50 184.75 Yuan/hm2，increasing bY 5.61%（2 667.42 Yuan/hm2）. Therefore，the treatment with mulches in a greenhouse would significantlY improve tobacco Yield and output value.

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ResPonsible editor：Xiaoxue WANG

ResPonsible Proofreader：Xiaoyan WP

增温育苗技术对烟叶生长发育及产质量影响研究

范才银1，詹 良1，林 志1，曾惠宇1，李建华1，何永秋1，李迪秦2*（1.衡阳市烟草公司常宁市分公司，湖南常宁421500；2.湖南农业大学，湖南长沙 410128）

2014年，在湘南烟区开展了烤烟工厂化育苗大棚套小棚膜增温育苗技术研究，结果表明：棚内10点和16点时段盘面和育苗池水体平均温度，大棚盖小棚膜处理均高于对照，增温效果好；烟苗生长势较强，其烟苗素质指标中的茎叶和根系的鲜重与干重均有增加；移栽到大田后，株高、茎围、叶面积等主要农艺性状指标比对照均有所增加，现蕾期和打顶期及成熟期略有提早；盖小棚膜处理平均产量为2 308.8 kg/hm2，比对照显著增产6.03%，平均产值为50 184.75元/hm2，比对照增加2 667.42元/hm2，增加5.61%。

烤烟；育苗；大棚套小棚膜；产质量

范才银（1976-），男，湖南隆回人，农艺师，主要从事烟草栽培与技术推广工作，E-mail：fancaiyin@163.com。*通讯作者，教授，主要从事烟草栽培生理研究，E-mail：ldqhnnd-2009@163.com。

2015-07-03

*Corresponding author.E-mail:ldqhnnd2009@163.com

Received:JulY 3，2015 Accepted:August 14，2015

修回日期 2015-08-14