Study On Key Factors Of Dominant Plant Type Of "Huang He Lou" Brand Yunyan 97 In South Anhui Province

Southern Anhui is a typical high-quality luzhou-flavor producing area in Nanling Hill ecological region of China,and an important raw material base for "Yellow Crane Tower" brand cigarette.The plant type of tobacco is closely related to the quality level of tobacco leaves.Cultivating the dominant plant type is the key to highlight the personalized quality style of tobacco leaves and to construct the characteristic quality system of tobacco leaves.At present,the standardization system of the dominant plant type of flue-cured tobacco has not been perfected,and the potential of the dominant plant type has not been fully utilized.In view of this,field experiments were carried out in Huanghelou Tobacco Leaf Science and Technology Park of Anhui province,Xuancheng,Anhui province in 2019.Using Yunyan 97 as the experimental material,an orthogonal design was adopted.Three planting densities were 1.67×104(D1),1.85×104(D2)and 2.08×104(D3)plants·hm-2,three nitrogen rates were 101.25(N1),116.25(N2)and 131.25(N3)kg·hm-2,and three leaf numbers were 13(L1),15(L2)and 17(L3)pieces(The number of effective leaves of Yunyan97 in southern Anhui was less).Sensory quality of post-flue-cured tobacco leaf was evaluated by the method of single feed tobacco sensory quality evaluation of China Tobacco Hubei Technology Center,which was evaluated by formula personnel of China Tobacco Hubei Technology Center.Taking planting density,nitrogen application rate and number of leaves left as regulation means,the relationship between key cultivation techniques,phenotypic indexes and internal quality of high-quality tobacco leaves was explored by "Inverse method",and the indexes for judging plant type were preliminarilyconstructed,in order to provide basis and reference for optimizing plant type supporting production technology and evaluation standard of China Tobacco Hubei.The main research results are as follows:1.The dry matter weight,stem and leaf Angle,leaf area and plant type of tobacco leaf are closely related to the yield and quality of tobacco leaf.The dry matter accumulation,the angle between stems and leaves and the leaf area of flue-cured tobacco were the key indexes affecting the plant type of flue-cured tobacco.When the sensory quality is optimal.the"tubular" plant type is beneficial to the formation of high-quality tobacco leaves when the leaf layer width,stem and leaf angle,dry matter accumulation and leaf area index of tobacco leaves over 60cm are appropriately increased.When the economic traits were optimal,leaf layer width,stem-leaf angle,dry matter accumulation and leaf area index of tobacco above 60cm decreased,while leaf layer width,stem-leaf angle,dry matter accumulation and leaf area index of tobacco below 60cm increased,so that the type of flue-cured tobacco showed a trend of "narrow at the top and wide at the bottom",namely,tower type.In order to improve the economic character of flue-cured tobacco,the middle and lower leaves of flue-cured tobacco were fully grown and developed.2.The relationship between leaf width and main phenotypic indexes of fresh leaf weight,leaf area,leaf angle and leaf layer width was investigated.In the experimental range,leaf layer width of flue-cured tobacco increased with the increase of fresh leaf weight,leaf area and leaf angle,and showed a significant linear relationship.In particular,the fitting coefficient of leaf angle was the best,followed by leaf area and fresh leaf weight.The fitting coefficient between stem and leaf angle and leaf layer width was above 0.7 for canopy structure of 0-3 0cm and 60-90cm,while the fitting coefficient between fresh leaf weight and leaf area and leaf layer width was below 0.7.In the ternary quadratic mathematical model,the fitting coefficient of leaf weight,leaf area and angle between stem and leaf with leaf layer width can reach above 0.78.3.The results showed that TIR was significantly related to the economic yield and sensory quality of tobacco leaves.In the ternary quadratic mathematical model,the fitting coefficients of interlayer ratio and the proportion of yield,output value and average price of high-quality tobacco were 0.925,0.929,0.752 and 0.993,respectively.The fitting coefficients of aroma quality score with B2F,C3F and X2F were 0.660,0.540 and 0.814,respectively.The fitting coefficients of total sensory score with B2F,C3F and X2F were 0.949,0.958 and 0.973,respectively.By analyzing its mathematical model,the following results can be obtained:①When TIR(30-60/0-30)was 1.12,TIR(60-90/30-60)was 0.82,and the ratio of leaf height to LLW(30-60)was 0.71,the total sensory evaluation score of B2F tobacco reached the maximum,and the estimated value was 93.64.When TIR(30-60/0-30)was 1.12,TIR(60-90/30-60)was 0.74,and the ratio of leaf height to LLW(30-60)was 0.76,the total sensory evaluation score of C3F tobacco reached the maximum,and the estimated value was 100.When TIR(30-60/0-30)was 1.12,TIR(60-90/30-60)was 0.82,and the ratio of layer height to LLW(30-60)was 0.83,the total score of sensory evaluation of X2F tobacco leaves reached the maximum,and the estimated value was 100.Comprehensive sensory score showed that TIR(30-60/0-30)was about 1.12,TIR(60-90/30-60)was 0.74-0.82,and the ratio of leaf height to LLW(30-60)was 0.71-0.83,indicating that the tobacco plant type was approximately "Tubular".②When TIR(30-60/0-30)was 0.84,TIR(60-90/30-60)was 0.72,and ratio of layer height to LLW(30-60)was 0.89,the tobacco yield reached the maximum,and the estimated value was 3136.90kg·hm-2.When TIR(30-60/0-30)was 0.84,TIR(60-90/30-60)was 0.72,and the ratio of layer height to LLW(30-60)was 1.09,the tobacco leaf output value reached the maximum,and the estimated value was 8.82×104 yuan·hm-2.When TIR(30-60/0-30)was 0.84,TIR(60-90/30-60)was 0.84,and the ratio of leaf height to LLW(30-60)was 0.45,the average leaf price reached the maximum,and the estimated value was 29.50 yuan·kg-1.The optimum ratio of superior tobacco was 1.12,0.95,and 0.40,respectively,when the ratio of superior tobacco was 30-60 and 0-30,and the ratio of superior tobacco was 0.95 and 0.40,respectively,and the estimated value was 29.50 yuan·kg-1.Considering the economic traits,the appropriate interlayer ratio(30-60/0-30)was 0.84,TIR(60-90/30-60)was 0.72-0.84,and the ratio of leaf height to leaf width(30-60)was 0.84-1.09,indicating that the tobacco plant was approximately "Tower type".4.With the increase of planting density,the quality of tobacco leaves gradually deteriorated,while the yield increased first and then decreased,and the yield reached the highest in D2.With the increase of nitrogen application rate,the quality of tobacco leaves gradually deteriorated,while the yield showed an increasing trend.With the increase of the number of leaves left,both the yield and quality of tobacco leaf increased first and then decreased,and reached the peak value at L2.The best treatment combination for tobacco quality was D1N1L2.D1N1L2 is beneficial to increase TIR(30-60/0-30)and TIR(60-90/30-60).The total sensory scores of B2F,C3F and X2F were 86.00,86.17 and 81.83 at the planting density of D1,respectively.The total sensory scores of B2F,C3F and X2F at N1 level were 85.33,86.17 and 80.83,respectively.The total sensory scores of B2F,C3F and X2F at L2 level reached 85.17,85.70 and 80.50,respectively.When D2N3L2 was the best cultivation treatment,the economic character of tobacco leaf was the best.D2N3L2 reduced TIR(30-60/0-30)and TIR(60-90/30-60),which made the tobacco plant "Tower" and the leaves fully developed,and then increased the dry matter accumulation and leaf area,and the yield increased.At D2 level,leaf yield,output value,proportion and average price of top-grade tobacco were 2830 kg·hm-2,7.73×104 yuan·hm-2,73.70%and 27.37 yuan·kg-1,respectively.At the N3 level,the yield,output value,proportion and average price of top-grade tobacco were 2.74×103kg·hm-2,7.43×104 yuan·hm-2,71.42%and 27.13 yuan·kg-1,respectively.At L2 level,the yield,output value.proportion and average price of top-grade tobacco were 2.70×103 kg·hm-2,7400 yuan·hm-2,73.84%and 27.38 yuan·kg-1,respectively.Therefore,based on the optimal quality requirement of "Yellow Crane Tower" brand for Wannan Yunyan 97,the planting density,nitrogen application rate and the number of leaves left were 1.67×104 plants·hm-2,101.25kg·hm-2 and 15 pieces;The plant type is "Tower type";The range of TIR(30-60/0-30),TIR(60-90/30-60)and leaf height/LLW(30-60)were 1.12,0.740.82 and 0.71-0.83,respectively.