Effects Of Three Agronomic Measures On Improving The Usability Of Upper Leaves Of Flue-cured Tobacco

At the present stage,the upper leaves of flue-cured tobacco in China have problems such as thick leaves,poor coordination of internal chemical components,and low industrial availability.In response to this phenomenon,this experiment adopted the Datian plot experiment and used tobacco grade NC55 as material to set different toppings.During the period,different plant growth regulators and different harvesting methods and other treatments,the effects of different treatment methods on improving the availability of upper tobacco leaves were explored.To improve the quality and usability of upper tobacco leaves,a production technology system for improving the availability of upper tobacco leaves was provided to provide theoretical support.The main results of this experiment are as follows:1.The effect of different topping periods on the quality of upper leaves was obvious.The effects of different topping periods on the quality of upper leaves were as follows: central flower opening topping> full flowering topping> budding period topping> heart topping,the tobacco plants that were topped when the central flower was open had better agronomic traits in the upper leaves,well-developed leaves,better appearance quality of the roasted tobacco leaves,appropriate and thick tobacco leaves,loose structure,low levels of nicotine and total nitrogen,the content of total sugar and reducing sugar is high,the content of each chemical component is appropriate and the proportion is more coordinated,and the score of the original smoke evaluation is the highest.2.The effect of different plant growth regulators on the quality of upper leaf tobacco showed that 50 mg/L indole acetic acid had the best effect,which could significantly increase the leaf length,leaf width and leaf area of the upper tobacco leaves,and effectively reduced the nicotine content of the upper leaf tobacco.And total nitrogen content,increase the contents of reducing sugar,total sugar and potassium,improving the internal chemical composition and coordination type of upper tobacco leaves,and improving the appearance quality and smoking quality of cured tobacco leaves;the effect of gibberellin and salicylic acid at the same concentration is not so good,but it also has a decisive role.3.The effect of different harvesting methods on the quality of upper leaves indicated that the disposable tobacco with stem harvesting had the best performance,the identity of tobacco leaves after curing was good,the oil content was adequate,the thickness was moderate and the structure was loose,and the appearance quality of the original tobacco was better.The content of chemical components is appropriate,the proportion is coordinated,and the evaluation results are excellent;the one-time harvesting treatment is the second;the tobacco leaves of conventional harvesting treatment are inferior to the other two in terms of appearance quality.