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【Objective】The present paper aimed to establish a BP (Back propagation) neural network (BPNN) automatic recognition system to achieve the standardization and quantification of flue-cured tobacco browning. 【Method】Taken the upper tobacco leaves of Yunyan 87 as a sample, scanning to obtain characteristic information such as tobacco leaf color, established a BP neural network to identify the degree of browning of flue-cured tobacco, and output the discrimination results, and compared the similarity with the results of artificially discriminating the browning of flue-cured tobacco as a reference. Through the analysis and comparison of appearance quality, conventional chemical composition, polyphenol content, TSNAs content and sensory quality changes, the accuracy of the BP neural network automatic recognition system and manual recognition results were veriofied.【Result】Establishing the BP neural network model could accurately identify tobacco browning level, and its recognition accuracy was 98.75%.There was no significant different among grading tobacco appearance quality, routine chemical compositions, polyphenol content, the content of TSNAs and sensory quality of change and the artificial recognition (P＜0.05).Which provided objective evaluation method for noise smoke, and the availability of tobacco leaves with different browning degrees was effectively distinguished.【Conclusion】The accuracy of the BP neural network recognition system for identifying the degree of tobacco browning is close to that of manual recognition. The BP neural network automatic recognition system can be used to replace manual recognition, which provides a reference for promoting the construction of tobacco BP. [ABSTRACT FROM AUTHOR]

[Objective]The present paper aimed to optimizating the fertilization technology that is suitable for flue-cured tobacco in Zhaotong tobacco area under the current situation, a 3 -year in situ experiment was conducted. [Method] Different fertilization ratios of field experiments were carried out in 3 consecutive years in Zhaoyang tobacco area by single factor randomized block design. By comparing the agronomic characters, economic characters and leaf quality of flue-cured tobacco under different treatments, the optimal nitrogen application rate and the optimal ratio of nitrogen and phosphorus were determined. [Result] The results showed that with the extension of planting years, the qualities of agronomic traits of flue-cured tobacco decreased, and the occurrence of disease increased. The yield increased slightly, but the proportion of high-quality tobacco leaves, the appearance quality of cured tobacco leaves and the coordination of chemical components of tobacco leaves showed a downward trend. In the comparison of different treatments, the amount of nitrogen application had a certain relationship with the maturity of tobacco leaves. In order to ensure the timely yellowing of tobacco leaves, it was necessary to control the nitrogen application rate. With the increase of nitrogen application rate, the leaf color of tobacco turned from light green to dark green, and the agronomic traits of flue-cured tobacco showed an increasing trend. Under the same nitrogen application rate, the plant height and effective leaf number increased when more phosphorus were applied. The dis ease incidence of non fertilization treatments was higher than that of other treatments, but there was little difference in the disease incidence among fertilization treatments. The coordination between economic characters and tobacco chemical composition in the treatment of 97. 5 and 120 kg/hm² nitrogen application was better than that of the treatment of 75 kg/hm² nitrogen application, and the treatment of 97. 5 kg/hm² nitrogen application showed better performance. Under the same nitrogen application rate, the coordination of economic characters and chemical composition of tobacco leaves in the N/ P ratio of 1: 1. 8 was better than that in the N/ P ratio of 1: 1.2. [Conclusion] In the continuous cropping plots of Zhaotong tobacco area, when the nitrogen application rate is 97. 5 kg/hm², and m (N) : m (P2O5): m (K2O) is 1: 1.8: 3, tobacco leaves can turn yellow in time, and the coordination of agronomic characters, economic characters and chemical components of flue-cured tobacco are good, and good yield and high quality of flue-cured tobacco can be achieved. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate the effects of wood vinegar on growth and physiology of flue-cured tobacco under drought stress, and provide a theoretical basis for in-depth application of wood vinegar in flue-cured tobacco cultivation. [Method] Yunyan 87 was used as research object to analyze the effects of peanut shell vinegar, fruit wood vinegar and peach shell vinegar on agronomic traits, SP AD value, malondialdehyde (MDA), proline (Pro) content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities of flue-cured tobacco under drought stress. [Result] Under normal watering and drought stress, the growth and SPAD value of fluecured tobacco applied with different wood vinegar were higher than that of the control, and peach shell vinegar performed better, the maximum SPAD values were 46. 6 and 44. 33 under normal watering and drought stress, respectively. The MDA contents were 3. 98-4. 31 and 4. 53-6. 12 f.LmoV g,respectively under normal watering and drought stress, and Pro contents were 123. 45-13. 427 and 183. 28-237. 97 f.Lg/ g, respectively. The contents of MDA and Pro of flue-cured tobacco under drought stress applied with different wood vinegar was higher than normal watering. The activities of SOD, POD and CAT in different treatments were all greater than those in normal watering, the average increasing rate was 24. 05 %, 47.36 % and 17. 30 %, respectively. [Conclusion]Wood vinegar could promote the growth of tobacco plants and improve the drought resistance of flue-cured tobacco. The peach shell vinegar solution performed better. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to improve the drought resistance of flue-cured tobacco in field growth period and solve the effect of drought from transplanting to rosette stage on tobacco yield and quality in Yunnan Province. [ Method] The study was carried out by systematic examination and evaluation of S4 traits for four plastic film mulching patterns ( furrow film mulching, M wide ridge double row film mulching, submembrane seedling transplanting, ordinary film mulching), including agronomic characters, photosynthetic properties, yield, benefit, physical properties, chemical composition and sensory quality of flue-cured tobaco MSK326. [Result] The 6 agronomic characters ( plant height, stem girth, internode distance, effective leaf number, maximum leaf width, maximum leaf area) of MSK326 tobacco plants with four plastic film mulching patterns were topping stage > pIU8perous period > rosette stage, among which 7 agronomic characters ( plant height, stem girth, internode distance, effective leaf number, maximum leaf length, maximum leaf width, maximum leaf area) of prosperous period and 3 photosynthetic characters ( stomata conductance, intracellular CO2 concentration, net photosynthetic rate) were significantly different, and the yield, the ratio of superior tobacco, middle and upper tobacco, average price and output value were significantly different among the four plastic film mulching patterns. The yield and output value of ridge and furrow mulching of flue-cured tobacco were the highest, which were 5. 53 % and 8. 58 % higher than those of common film mulching of flue-cured tobacco, respectively. Ridge and furrow film mulching patterns were the highest not only in the 7 agronomic characters ( plant height, stem girth, internode distance, effective leaf number, maximum leaf length, maximum leaf width, maximum leaf area ), 4 photosynthetic characters ( stomata conductance, intracellular CO2 concentration, net photosynthetic rate) 6 yield / benefit traits (yield, first-class tobacco, medium class tobacco, middle/upper class tobacco, average price, value of output) and 5 physical characters ( opening rate, leaf thickness, single leaf llllJl!8, equilibrium moisture content, physical property index) of tobacco plants, hut also the highest in S chemical components ( total sugar, reducing sugar, potassium, rate of sugar to nicotine, rate of potassium to chlorine), 6 8enllOI'}' qualities ( fragrant temperament, fragrant gas volume, miscellaneous gas, permeable, flexibility, sweetness ) and total score of smoking of the middle tobacco leaves. [ Conclusion] The agronomic characters, yield characters and economic benefits of flue-cured tobacco covered with furrow film mulching were the highest, and the chemical composition and internal quality of middle tobacco leaves were more coordinated. These results revealed that the new planting model of flue-cured tobacco ridge and furrow mulching could provide reference for solving the drought of tobacco transplanting period and improving the yield, quality and economic benefit of tobacco. [ABSTRACT FROM AUTHOR]

[Objective] The aim of this paper was to analyze the influence of altitude on chemical components of tobacco leaves in Yuxi region. [ Method] The effects of altitude on flue-cured tobacco chemical components were studied in the form of spot sampling. [ Result] The results indicated that there were a significant positive correlation between the altitude and the nicotine of upper leaves and a negative correlation between the altitude and the nicotine of middle and lower leaves. There were a positive correlation between the altitude and total nitrogen content of upper and middle leaves and a negative correlation between the altitude and total nitrogen content of lower leaves. The contents of total sugar and reducing sugar increased first and then decreased with the increase of altitude, with the highest content of reducing sugar at the altitude of 1728 m. The content of potassium oxide did not change with the change of altitude. The contents of potassium oxide of three parts of tobacco leaves were the lowest at the altitude of 1900 m. The maximum and minimum values of chloridion content were at the altitude of 1728 and 1900 m respectively. The chloridion contents were equivalent at the altitude of 1313 and 2200 m, as well as 1532 and 1900 m. In the aspect of harmony, the difference between total sugar and reducing sugar in three parts of tobacco leaves increased first and then decreased with the increase of altitude, and tin* maximum values were all at the altitude of 1728 m. The sugar-nicotine ratios of lower and middle leaves were higher than upper leaves as a whole, and the sugar-nicotine ratios of middle and lower leaves increased first and then decreased with the increase of altitude. The nitrogen-nicotine ratio of upper leaves was lower than that of middle and lower leaves, and the nitrogen-nicotine ratios of middle and lower leaves increased with the increase of altitude. The altitude has little influence of the ratio of the non-nieotine nitrogen and total nitrogen in three parts of tobacco leaves. [ Conclusion] Altitude has great influence on the contents of nicotine, total nitrogen, total sugar, reducing sugar, as well as the difference between total sugar and reducing sugar, sugar-nicotine ratio and nitrogen-nicotine ratio. Altitude has little influence on the content of potassium oxide, chloridion and the ratio of non-nicotine nitrogen and total nitrogen. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to clarify the curing characteristics of different quality upper leaves, such as green tobacco leaves, few rainy sunshine tobacco and multi-fermented tobacco leaves. [Method]A dark box and an electric oven were used to study the yellowing characteristics and water loss characteristics of the upper leaves of different qualities and dynamic changes of moisture, color and pigment and activity of polyphenol oxidase in flue cured tobacco during curing of Hong-hua-da-jin-yuan. [Result]In dark box and curing test, the yellowing speed of more fertilizer and turn green tobacco leaves was slower, the water loss speed was faster, the yellowing speed of rainy sunshine tobacco leaves was faster, and the water loss speed was slower;during the curing process, the degradation rate of the pigments in the turn green and more fertilizer tobacco leaves was slower, and the degradation rate of the pigments in the rainy sunshine tobacco leaves was faster;starch content was more fertilizer> turn green> rainy sunshine;polyphenol oxidase activity was rainy sunshine> more fertilizer>turn green;after curing, the proportion of ash and black bad smoke was relatively high, and rainy sunshine and more fertilizer tobacco leaves’ proportion of turn green tobacco leaves was higher, the percentage of baked green tobacco leaves was relatively high. [Conclusion] The turn green tobacco leaves are less roasting and have good curing resistance, rainy sunshine tobacco leaves are easy to roast and have poor roasting resistance, more fertilizer tobacco leaves is difficult to turn yellow, easy to brown, easy to roast and roasting resistance are poor, in the actual production process, the curing process should be adjusted according to its curing characteristics, to improve the quality of the roasted tobacco leaves. [ABSTRACT FROM AUTHOR]