[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship bet...[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship between disease occurrence and meteorological factors during the field growth period was examined by analyzing the prevalence of flue-cured tobacco virus diseases,brown spot,and total disease in the Shiyan tobacco-growing area before(2013-2017)and after(2018-2022)the well-cellar early transplanting of robust tobacco seedlings.[Results]The implementation of a well-cellar early transplanting technique of robust seedlings resulted in a reduction in the average incidence of tobacco virus disease,brown spot,and total disease by 0.83%,8.85%,and 7.91%,respectively,in comparison to the incidence observed prior to early transplanting.These findings suggest that early transplanting can significantly reduce the incidence of flue-cured tobacco diseases.Prior to the well-cellar early transplanting of robust tobacco seedlings,there was a significant(including highly significant)positive correlation between the incidence of brown spot and total disease and precipitation in August and September.The incidence of brown spot and total disease in tobacco plants was found to be significantly positively correlated with May precipitation and significantly negatively correlated with May sunshine hours following the well-cellar early transplanting of robust seedlings.The advancement of the transplanting period by 20 d resulted in a reduction in the growing period of tobacco plants in the field under autumn rains(late August to November)in western China.This effectively circumvented the suitable conditions for disease occurrence and can reduce the incidence of disease.[Conclusions]This study offers a framework for enhancing the quality and efficiency of flue-cured tobacco production in the northwest tobacco-growing area of Hubei.展开更多
[Objective] The aim was to study the distribution characteristics of soil pH values and its correlation with soil nutrients in tobacco-growing areas. [Method] Soil nutrients of 43 samples from tobacco-growing areas in...[Objective] The aim was to study the distribution characteristics of soil pH values and its correlation with soil nutrients in tobacco-growing areas. [Method] Soil nutrients of 43 samples from tobacco-growing areas in Dali City were analyzed.[Results] The results showed that average pH value of tobacco-planting soil in Dali City was 6.52, soil samples which suited for flue-cured tobacco cultivation accounted for 72.09% of total soil samples. In four soil types of tobacco-growing areas, the pH values in a descending order were as follows： alluvial soil〉 paddy soil 〉purple soil〉 red soil. At the altitude range of 1 780-2 200 m, soil pH values showed a gradual decreasing trend. The average contents of soil organic matters were relatively abundant and generally suited for high-quality tobacco cultivation; the average contents of soil alkali-hydrolyzable nitrogen, available phosphorus, exchangeable calcium and exchangeable magnesium were generally at medium and abundant level, however,their rations under the medium level in some tobacco-growing areas were 6.98%,11.63%, 2.33% and 4.65%, respectively; moreover, soil with lower available potassium contents occupied a large proportion, namely 58.14%. [Conclusion] Soil pH values had significant correlation with exchangeable magnesium and exchangeable magnesium, however, they had no significant correlation with other soil nutrients.展开更多
Based on the actual situation of tobacco production in South Anhui tobacco-growing area,the paper analyzes several major constraints,and discusses several aspects such as tobacco production human resources,production ...Based on the actual situation of tobacco production in South Anhui tobacco-growing area,the paper analyzes several major constraints,and discusses several aspects such as tobacco production human resources,production of large-scale cultivation,science and technology service providers,the standardized production management and production security system. The countermeasures and suggestions for sustainable development are also put forward to provide a reference for the sustainable development of tobacco-growing area in South Anhui.展开更多
Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-...Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-growing areas. The assessment results indicate that there are 8 risks and 1 opportunity. Action and monitoring plans have been made for medium and high risks as well as opportunity,to reduce impact on biodiversity.展开更多
To investigate the spatial synergy between agricultural development level and transport superiority degree in grain-producing areas of the central Jilin Province and the driving mechanism between them,22 counties in t...To investigate the spatial synergy between agricultural development level and transport superiority degree in grain-producing areas of the central Jilin Province and the driving mechanism between them,22 counties in the central Jilin Province were used as the research units to calculate agricultural development level and transport superiority degree using the entropy weighting method,weighted travel time and raster cost distance.The spatial econometric model was used to analyze the mechanism of the mutual influence between the two.The main conclusions are as follows.1)Agricultural development level around Changchun,the provincial capital city,and in the areas of Changchun-Jilin and Changchun-Gongzhuling is high,whereas the development level of the counties in the southwest is low.2)Transport superiority degree of each county has improved,the overall connectivity of the road networks has been optimized,and the level of transportation accessibility has shown the development trend of‘centralization’,exhibiting the characteristics of proximity diffusion.3)Locally,there is spatial heterogeneity in the mutual driving effects of the two,with six main patterns.4)The theoretical conditions of von Thunen’s agricultural location have changed under the conditions of market economy due to the improvement of the transport networks,the new model of agricultural development,and the changes of the market system.展开更多
The superior vena cava(SVC)is the main component of non-pulmonary vein(PV)ectopy in patients with atrial fibrillation(AF).Researchers have found that epicardial adipose tissue(EAT)volume is related to the AF substrate...The superior vena cava(SVC)is the main component of non-pulmonary vein(PV)ectopy in patients with atrial fibrillation(AF).Researchers have found that epicardial adipose tissue(EAT)volume is related to the AF substrate,which can be defined by the low voltage area(LVA).This study aimed to investigate the relationship between SVC-EAT and SVC-AF.Twenty-six patients with SVC-AF triggers were identified as the SVC-AF group.Other three groups were defined and included as the LVA-AF group(LVA>5%),non-LVA-AF group(LVA<5%),and physical examination(PE)group.EAT around left atrium(LA-EAT)and SVC-EAT volumes were obtained using a cardiac risk assessment module.According to the SVC/LA-EAT ratio,there are significant differences between the SVC-AF group and the three control groups(the SVC-AF group 0.092±0.041 vs.the LVA-AF group 0.054±0.026,the non-LVA-AF group 0.052±0.022,and the PE group 0.052±0.019,all P<0.001).Receiver operating characteristic curve analysis suggests the optimal cut-off point of SVC/LA-EAT ratio is 6.8%for detecting SVC-AF patients,with 81.1%sensitivity,73.1%specificity,and an area under the curve of 0.83(95%confidence interval,0.75-0.91).Those with SVC-AF have a higher SVC/LA-EAT ratio and empirical SVC isolation could be considered if the SVC/LA-EAT ratio was over 6.8%.展开更多
基金Supported by Research Program on Prevention and Control Technology of Tobacco Potato Virus Y Disease(SYK2023-06).
文摘[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship between disease occurrence and meteorological factors during the field growth period was examined by analyzing the prevalence of flue-cured tobacco virus diseases,brown spot,and total disease in the Shiyan tobacco-growing area before(2013-2017)and after(2018-2022)the well-cellar early transplanting of robust tobacco seedlings.[Results]The implementation of a well-cellar early transplanting technique of robust seedlings resulted in a reduction in the average incidence of tobacco virus disease,brown spot,and total disease by 0.83%,8.85%,and 7.91%,respectively,in comparison to the incidence observed prior to early transplanting.These findings suggest that early transplanting can significantly reduce the incidence of flue-cured tobacco diseases.Prior to the well-cellar early transplanting of robust tobacco seedlings,there was a significant(including highly significant)positive correlation between the incidence of brown spot and total disease and precipitation in August and September.The incidence of brown spot and total disease in tobacco plants was found to be significantly positively correlated with May precipitation and significantly negatively correlated with May sunshine hours following the well-cellar early transplanting of robust seedlings.The advancement of the transplanting period by 20 d resulted in a reduction in the growing period of tobacco plants in the field under autumn rains(late August to November)in western China.This effectively circumvented the suitable conditions for disease occurrence and can reduce the incidence of disease.[Conclusions]This study offers a framework for enhancing the quality and efficiency of flue-cured tobacco production in the northwest tobacco-growing area of Hubei.
基金Supported by Dali Prefecture Science and Technology Planning Project--"Analysis and Evaluation on Tobacco-planting Soil of Dali Prefecture"~~
文摘[Objective] The aim was to study the distribution characteristics of soil pH values and its correlation with soil nutrients in tobacco-growing areas. [Method] Soil nutrients of 43 samples from tobacco-growing areas in Dali City were analyzed.[Results] The results showed that average pH value of tobacco-planting soil in Dali City was 6.52, soil samples which suited for flue-cured tobacco cultivation accounted for 72.09% of total soil samples. In four soil types of tobacco-growing areas, the pH values in a descending order were as follows： alluvial soil〉 paddy soil 〉purple soil〉 red soil. At the altitude range of 1 780-2 200 m, soil pH values showed a gradual decreasing trend. The average contents of soil organic matters were relatively abundant and generally suited for high-quality tobacco cultivation; the average contents of soil alkali-hydrolyzable nitrogen, available phosphorus, exchangeable calcium and exchangeable magnesium were generally at medium and abundant level, however,their rations under the medium level in some tobacco-growing areas were 6.98%,11.63%, 2.33% and 4.65%, respectively; moreover, soil with lower available potassium contents occupied a large proportion, namely 58.14%. [Conclusion] Soil pH values had significant correlation with exchangeable magnesium and exchangeable magnesium, however, they had no significant correlation with other soil nutrients.
文摘Based on the actual situation of tobacco production in South Anhui tobacco-growing area,the paper analyzes several major constraints,and discusses several aspects such as tobacco production human resources,production of large-scale cultivation,science and technology service providers,the standardized production management and production security system. The countermeasures and suggestions for sustainable development are also put forward to provide a reference for the sustainable development of tobacco-growing area in South Anhui.
基金Supported by Technology Project of Yunnan Tobacco Monopoly Bureau(201-5YN25)
文摘Using the method in Biodiversity Risk and Opportunity Assessment Handbook of British American Tobacco Biodiversity Partnership,we assess biodiversity risks and opportunities in BAT and China's cooperative tobacco-growing areas. The assessment results indicate that there are 8 risks and 1 opportunity. Action and monitoring plans have been made for medium and high risks as well as opportunity,to reduce impact on biodiversity.
基金Under the auspices of Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19040500)。
文摘To investigate the spatial synergy between agricultural development level and transport superiority degree in grain-producing areas of the central Jilin Province and the driving mechanism between them,22 counties in the central Jilin Province were used as the research units to calculate agricultural development level and transport superiority degree using the entropy weighting method,weighted travel time and raster cost distance.The spatial econometric model was used to analyze the mechanism of the mutual influence between the two.The main conclusions are as follows.1)Agricultural development level around Changchun,the provincial capital city,and in the areas of Changchun-Jilin and Changchun-Gongzhuling is high,whereas the development level of the counties in the southwest is low.2)Transport superiority degree of each county has improved,the overall connectivity of the road networks has been optimized,and the level of transportation accessibility has shown the development trend of‘centralization’,exhibiting the characteristics of proximity diffusion.3)Locally,there is spatial heterogeneity in the mutual driving effects of the two,with six main patterns.4)The theoretical conditions of von Thunen’s agricultural location have changed under the conditions of market economy due to the improvement of the transport networks,the new model of agricultural development,and the changes of the market system.
文摘The superior vena cava(SVC)is the main component of non-pulmonary vein(PV)ectopy in patients with atrial fibrillation(AF).Researchers have found that epicardial adipose tissue(EAT)volume is related to the AF substrate,which can be defined by the low voltage area(LVA).This study aimed to investigate the relationship between SVC-EAT and SVC-AF.Twenty-six patients with SVC-AF triggers were identified as the SVC-AF group.Other three groups were defined and included as the LVA-AF group(LVA>5%),non-LVA-AF group(LVA<5%),and physical examination(PE)group.EAT around left atrium(LA-EAT)and SVC-EAT volumes were obtained using a cardiac risk assessment module.According to the SVC/LA-EAT ratio,there are significant differences between the SVC-AF group and the three control groups(the SVC-AF group 0.092±0.041 vs.the LVA-AF group 0.054±0.026,the non-LVA-AF group 0.052±0.022,and the PE group 0.052±0.019,all P<0.001).Receiver operating characteristic curve analysis suggests the optimal cut-off point of SVC/LA-EAT ratio is 6.8%for detecting SVC-AF patients,with 81.1%sensitivity,73.1%specificity,and an area under the curve of 0.83(95%confidence interval,0.75-0.91).Those with SVC-AF have a higher SVC/LA-EAT ratio and empirical SVC isolation could be considered if the SVC/LA-EAT ratio was over 6.8%.
