| In enshi,hubei province in 2018 laifeng cigars planting base for field tests,on the introduction of 14 varieties of botany character,agronomic characters and disease conditions,chemical components and neutral aroma substances and sensory quality evaluation analysis,and study the different nitrogen levels and the influence of different planting density on LaiFeng tobacco quality.The research results are as follows:1.Trial breeding of new varietiesThe 14 new varieties of cigars introduced from the botanical and agronomic characteristics are suitable for the demand of cigar raw materials.Tobacco growing in laifeng area is prone to bacterial wilt,and overripe harvest is likely to lead to black shank disease,but the overall disease is not serious and has little impact on cigar production.In terms of appearance quality,gu-5,gu-8,shi-1 and si-1 varieties are better.In terms of physical characteristics,gu-4 variety,gu-5 variety,shi-1 variety and shi-2 variety have relatively good physical characteristics.The chemical compositions of gu-5,yin-1,shi-2,si-1 and nuo-2 were better.Interms of sensory quality evaluation,gu-5,gu-6 and shi-1 varieties were relatively good.By comprehensive comparison,gu-5 variety and shi-1 variety are suitable for planting in laifeng tobacco area.2.Effects of different nitrogen application levels on the quality of laifeng cigarThe height,maximum leaf length,maximum leaf width and stem circumference of tobacco plants increased significantly with the increase of nitrogen application.The agronomic characters of tobacco plants were the best when nitrogen fertilizer was 210kg/hm2.With the increase of nitrogen application,the content of total sugar and reducing sugar in tobacco leaves would decrease,the content of nicotine in tobacco leaves would increase and the absorption of potassium in tobacco leaves would be promoted to some extent.Nitrogen application was significantly correlated with leaf weight,leaf mass weight and leaf thickness of tobacco leaves.Increased nitrogen application could increase leaf weight,leaf mass weight,leaf thickness and leaf equilibrium moisture content of cigar tobacco leaves,but nitrogen application had no significant effect on stem content of tobacco leaves.With the increase of nitrogen application,the content of new phytadiene will be significantly increased,and the content of other aromatic substances will be increased under the condition of a certain amount of nitrogen fertilizer,and the total amount of aromatic substances will be reduced when the nitrogen application is too high or too low.Increasing nitrogen application within a certain range can increase manganese,sodium,calcium and magnesium in tobacco leaves.However,potassium decreased in the range of 210kg/hm2-240kg/hm2 of nitrogen application.With the increase of nitrogen application,the ash content of cigar increased greatly,but the increase of ash content decreased after nitrogen application was too high.With the increase of nitrogen application,the aroma quality,aroma quantity,transmission degree,concentration and irritation of cigar tobacco increased,while the lumpiness and dryness of cigar tobacco decreased.The tobacco leaves had little effect on its fineness,cleanliness and sweetness.The gray and burning properties of tobacco leaves were improved with the increase of nitrogen application.Through comprehensive comparison,field growth and tobacco leaf quality of tobacco plants with nitrogen application rate of 210kg/hm2 were optimized3.Influence of planting density on quality of laifeng cigarUnder the conditions of different planting densities,most agronomic traits of tobacco and tobacco plants were significantly different in the late growth stage of field,while there was no significant difference in the early growth stage of field.The leaf length,leaf width,plant height and stem circumference of tobacco plants increased with the decrease of density,while the number of leaves decreased with the decrease of density.Among them,the agronomic traits were the best when the planting density was 20833 plants/hm2(120cm*40cm).With the decrease of planting density,the content of total sugar and reducing sugar in tobacco leaves would increase,but the differences between treatments were not significant.The content of nicotine in tobacco leaves increased with the decrease of planting density and decreased with the increase of planting density.The effects of different planting densities on potassium and chlorine contents were not obvious.Planting density was negatively correlated with leaf weight,leaf weight and leaf thickness,but had no significant effect on the balanced moisture content and stem content of tobacco leaves.With the decrease of planting density,the content of new phytadiene in tobacco leaves increased obviously,and the content of other aromatic substances increased under a certain planting density.With the decrease of planting density,the content of boron,copper,iron,manganese,calcium and magnesium in tobacco decreased.There was no significant change in the content of sodium and zinc.Phosphorus content increased with the decrease of density.With the decrease of planting density,ash content of tobacco leaves tended to increase,but when the planting density decreased to a certain extent,ash content remained stable.With the decrease of planting density,the aroma quality,aroma quantity,smoke concentration,strength and clumpness of cigar tobacco were improved,and the impurity,fineness and cleanliness were decreased,but the planting density had no significant effect on the dryness,sweetness and combustibility of tobacco leaves.Through comprehensive comparison,when the planting density was 20833 plants/hm2(120cm*40cm),the growth situation and tobacco leaf quality of tobacco plants in field were the best. |
