| As a kind of popular tobacco products in the world,cigar has been popular in our country in recent years and the cigar industry has developed quickly.However,owing to our short planting history and backward production technology,it has led to lack of good quality cigar materials domestically made and it is dependent on foreign imports in the long run.Therefore,it is of great significance to study the suitable production technology of domestic cigar for improving the yield and quality of cigar leaf and promoting the rapid and good development of domestic cigar industry.In this study,field experiments were carried out in the cigar producing area of Danjiangkou,Hubei Province.Through field agronomic traits investigation,physiological indexes such as nutrient absorption and utilization,photosynthesis,and stress resistance were analyzed.To study the effects of different transplanting periods and planting densities on the growth and physiological characteristics of cigar wrappers cultivar"CHUXUE 26（CX-26）"and cigar wrappers cultivar"CHUXUE 14（CX-14）"in the resettling growth stage,vigorous growing stage and mature stage and to determine the best cultivation techniques suitable for the production of high-quality cigar tobacco materials in Danjiangkou tobacco-producing area of Hubei Province.The main results of the study are as follows:1.Effects of transplanting period on growth,development and physiological characteristics of cigar"CX-26"Five transplanting periods were set in this experiment:April 10,April 20,April 30,May 10 and May 20.The results showed that the plant height,maximum leaf area,stem circumference and biomass of the cigar transplanted on April 30 increased significantly in each growth stage compared with that on April 10 and April 20,and the growth and development of the cigar were better.The maximum leaf area at mature stage reached1271.75 cm2 on April 30,which was significantly higher than that on May 10 and May 20,increasing by 5.9%and 30.2%respectively.At the same time,the net photosynthetic rate of the cigars transplanted on April 30 reached 23.05μmol CO2·m-2·s-1,the activity ofα-amylase reached 1.91 U/g and 1.76 U/g,respectively,at vigorous growing stage and the mature stage,and the potassium content of the leaves reached 2.5%,which was relatively higher than that of other treatments.The activity of superoxide dismutase was 1652.63 U/g and 1602.02 U/g in cigar leaves at vigorous growing and mature stages,which was relatively low compared with other treatments.The proportion of wrapper in the cigar transplanting on April 30 was 18.65%;The per mu yield is 166.77 kg/mu,and the per mu output value is 14668.63 yuan/mu,which is relatively high compared with other treatments,and has a good comprehensive appearance quality.In conclusion,the more suitable variety"CX-26"was transplanted in Danjiangkou cigar area on April 30,which was conducive to the production of high-quality cigar leaves.2.Effects of transplanting period on growth,development and physiological characteristics of cigar"CX-14"Four transplanting periods were set in this experiment:April 10,April 20,April 30,and May 10.The results showed that,similar to the results of"CX-26",the plant height,the maximum leaf area and aboveground biomass of the cigar transplanted on April 30 were about 130.85 cm2,995.40 cm2 and 86.57 g in vigorous growing stage,which were significantly higher than those on April 10 and April 20,and the overall growth and development were better.However,there was relatively little difference in agronomic characters between April 30 transplanting and May 10 transplanting.At the same time,there were no significant differences in antioxidant indexes andα-amylase activity between different treatments at vigorous growing stage and mature stage.The proportion of filler in the cigar transplanted on April 30 was 75.3%;the yield of cigars transplanted on April 30was 169.21 kg/mu,12674.88 yuan/mu,which was relatively high compared with other treatments,and had better comprehensive appearance quality.In conclusion,it is more suitable for the growth and development of cigar"CX-14"in Danjiangkou cigar area from April 20 to April 30,which is conducive to the production of high-quality cigar leaves.3.Effects of planting density on growth,development and physiological characteristics of cigar"CX-26"Six planting density treatments were set in this experiment:90 cm×30 cm,100 cm×30cm,100 cm×35 cm,100 cm×40 cm,110 cm×40 cm and 110 cm×45 cm.The results showed that with the decrease of planting density,the total biomass,plant height,maximum leaf area,the Angle between stems and leaves,and root activity of cigar plant increased gradually.At the same time,when the planting density was 100 cm×40 cm,the SOD activity and MDA content of cigar in mature stage were about 1733.58 U/g and 8.32 nmol/g,which were significantly reduced compared with high density treatment,and the degree of leaf film oxidation was relatively lower.Nitrogen content reached 1.21%,which was relatively higher than that of high-density treatment.At the same time,α-amylase activity in the leaves at vigorous growing stage was significantly higher than that of high density treatment,reaching 1.85 U/g.The proportion of wrapper in 100 cm×40 cm planting density treatment was 19.94%,and the output value of per mu was 15303.61 yuan/mu,which was relatively higher than that of other treatments,and had better comprehensive appearance quality.In conclusion,the planting density of 100 cm×40 cm in Danjiangkou cigar area is more suitable for the growth and development of cigar"CX-26",which is conducive to improving the quality of cigar leaves and achieving the relative balance between the yield and quality of cigar leaves.4.Effects of planting density on growth,development and physiological characteristics of cigar"CX-14"Five planting density treatments were set up in this experiment:110 cm×35 cm,110cm×40 cm,120 cm×40 cm,120 cm×45 cm and 120 cm×55 cm.The results showed that,similar to the results of"CX-26",with the decrease of planting density,the overall biomass,plant height,maximum leaf area,stem circumference,the angle between stems and leaves,and root activity of cigar plant increased gradually.At the same time,when the planting density was 120 cm×45 cm,the SOD activity of cigar in mature stage was about 1897.17U/g,which was significantly decreased compared with the high density treatment.Nitrogen content reached 1.38%,which was relatively higher than that of high density treatment.Theα-amylase activity in the leaves at vigorous growing stage was significantly increased,reaching 2.15 U/g.However,there was no significant difference in MDA content among all treatments.In conclusion,the planting density of 120 cm×45 cm in Danjiangkou cigar area is more suitable for the growth and development of cigar"CX-14",which is conducive to improving the quality of cigar leaves and achieving the relative balance between the yield and quality of cigar leaves. |
