Research On Improving The Maturity Of Flue-cured Tobacco Upper Leaves In Laiwu Tobacco Area

The upper tobacco leaves in Shandong tobacco area have a series of problems such as thicker leaves,deep color,tight tissue structure,poor maturity,and incoordination of internal chemical composition.This experiment focuses on the core of promoting early maturity of flue-cured tobacco in Laiwu tobacco area and improving the availability of tobacco leaves.The study is carried out through measures such as transplanting period regulation,water supply regulation,plant type regulation,and physical and chemical regulation of tobacco plant growth and development in the late field.The maturity and availability make the quality of upper tobacco leaves more in line with the quality requirements of my country’s cigarette industry for tobacco leaf raw materials,and provide a certain theoretical basis for the Laiwu tobacco area to establish a production technology system to improve the maturity of upper tobacco leaves.The main research results of this experiment are as follows:(1)Different transplanting periods have significant effects on the maturity of the whole plant and upper leaves of flue-cured tobacco.The most suitable transplanting time is May 5th.At this time,the upper leaves of the transplanted tobacco plants have better maturity.The upper 18 th leaf position of the leaf length and leaf width respectively reach 74.74 cm and43.50 cm,and the appearance quality is better.it is good.After the flue-cured tobacco leaves have good economic properties,the yield and output value are high,and the average price has reached 19.16 yuan/kg.With the advancement of the transplanting time,the main agronomic traits and economic traits of tobacco plants after curing showed a downward trend.(2)The results of the effects of different water supply on the maturity of the whole plant and upper leaves of flue-cured tobacco showed that sufficient water supply(watering volume of 2000ml)promoted the maturity of flue-cured tobacco.With the decrease of water supply,all agronomic traits of flue-cured tobacco decreased significantly,and the maturity of upper leaves decreased.(3)The upper leaves of flue-cured tobacco with secondary topping 7 days after the first topping in the field of flue-cured tobacco have excellent agronomic characteristics,promote leaf opening,moderate leaf thickness,increase production value,increase average price,and increase the proportion of high-quality tobacco.(4)At the later stage of flue-cured tobacco field growth,the semi-circular cutting treatment at the base of the stem after topping can improve the appearance quality of the upper tobacco leaves,promote the growth of the upper leaves,and significantly increase the fresh dry weight of single leaf by 13.79% and 8.01% compared with conventional production.The economic characteristics of flue-cured tobacco leaves are the best,the output value is increased by 12.60% compared with the control,and the difference is significant,and the proportion of high-quality tobacco is significantly increased by 4.79%.Root wound treatment30 days after topping can effectively increase the growth rate of the upper leaves,improve the appearance quality and promote the maturity of the upper tobacco leaves.The increase in leaf length and leaf area of the upper tobacco leaves of the tobacco plant is significantly increased by 0.87% and 1.12% compared with conventional production.The increase in width by 0.25%is not significant.With the advancement of root injury time,the comparison control group inhibited the physical properties of the upper tobacco leaves,resulting in a decline in tobacco leaf maturity.Physical regulation of flue-cured tobacco in the late field can promote the maturation of the upper leaves of the tobacco plant and improve the usability.(5)Under spraying 500mg/kg ethephon,the various agronomic characteristics of tobacco plants were superior to conventional growth and the difference was significant: the number of effective leaves increased by 13.16%,the leaf length increased by 6.13%,and the leaf width increased significantly by 19.61%.The internal chemical composition of the ethephon treated tobacco leaves is more coordinated and the quality of the tobacco leaves is better.The nicotine content of the upper leaves was significantly reduced by 0.52% compared with the upper tobacco leaves of the conventional treatment,and the total sugar and reducing sugar contents were significantly increased by 4.47% and 3.92%.The nitrogen content was reduced by 0.21% and the difference was not significant.The upper tobacco leaves sprayed with 200mg/kg gibberellic acid after the topping of the tobacco plants showed better opening and lower leaf thickness,and the nicotine content decreased by 21.6% compared with the conventional treatment.The difference was significant.The total sugar content was significantly reduced by 8.46%.The total nitrogen content of the control increased by 5.56%and the difference was significant.The potassium content exceeds 2%,which improves the ratio of potassium to chlorine,makes the chemical composition more coordinated,and promotes the maturation of the upper leaves.