Pub Date : 2021-01-01DOI: 10.3381/tobsci-d-20-00001
Andrea B. Keeney, R. Pearce, W. Bailey
Field trials were conducted in Princeton, Murray, and Lexington, KY in 2016–2018 to determine response of dark and burley tobacco to potassium source (potassium sulfate or potassium chloride) and potassium rate (0, 93, 186, or 279 kg K ha−1). Field sites that showed higher potential for potassium yield response were selected based on low soil test potassium levels from soil samples collected in early spring each year. All potassium applications were made between 1 and 10 days before transplanting. Significant yield responses to potassium were seen in 5 of 12 trials at sites that had initial soil test potassium levels of ≤150 kg K ha−1. Although cured leaf chloride levels were >1% on average where potassium chloride was used, negative effects on cured leaf moisture were only seen in 1 of 12 trials, and negative effects on quality grade index were not seen in any trial. The most consistent effect of potassium chloride application seen in this research was a 28% reduction in average total tobacco-specific nitrosamines (TSNA) compared to potassium sulfate application. These results showing lower TSNA from potassium chloride applications, along with minimal effects on moisture and quality grade index, may cause the tobacco industry to reconsider the long-standing preference for potassium sulfate as the potassium source for tobacco production.
2016-2018年，在肯塔基州的普林斯顿、默里和列克星敦进行了田间试验，以确定黑烟和白烟对钾源(硫酸钾或氯化钾)和钾速率(0、93、186和279 kg K ha−1)的响应。根据每年早春采集的土壤样品中较低的土壤试验钾水平，选择钾产量响应潜力较大的大田立地。所有钾肥均在移栽前1 ~ 10天施用。在初始土壤试验钾含量≤150 kg K ha−1的地点进行的12个试验中，有5个试验对钾的产量有显著的响应。虽然施用氯化钾的烤烟叶片氯含量平均>1%，但12个试验中只有1个试验对烤烟叶片水分有负面影响，没有试验对品质等级指数有负面影响。在本研究中，氯化钾施用最一致的效果是与硫酸钾施用相比，烟草特异性亚硝胺(TSNA)平均总量减少28%。这些结果表明，氯化钾施用的TSNA较低，对湿度和质量等级指数的影响极小，可能会导致烟草行业重新考虑长期以来首选硫酸钾作为烟草生产钾源的做法。
{"title":"Effect of Potassium Source and Rate on Yield, Quality, and Tobacco-Specific Nitrosamines in Dark and Burley Tobacco","authors":"Andrea B. Keeney, R. Pearce, W. Bailey","doi":"10.3381/tobsci-d-20-00001","DOIUrl":"https://doi.org/10.3381/tobsci-d-20-00001","url":null,"abstract":"Field trials were conducted in Princeton, Murray, and Lexington, KY in 2016–2018 to determine response of dark and burley tobacco to potassium source (potassium sulfate or potassium chloride) and potassium rate (0, 93, 186, or 279 kg K ha−1). Field sites that showed higher potential for potassium yield response were selected based on low soil test potassium levels from soil samples collected in early spring each year. All potassium applications were made between 1 and 10 days before transplanting. Significant yield responses to potassium were seen in 5 of 12 trials at sites that had initial soil test potassium levels of ≤150 kg K ha−1. Although cured leaf chloride levels were >1% on average where potassium chloride was used, negative effects on cured leaf moisture were only seen in 1 of 12 trials, and negative effects on quality grade index were not seen in any trial. The most consistent effect of potassium chloride application seen in this research was a 28% reduction in average total tobacco-specific nitrosamines (TSNA) compared to potassium sulfate application. These results showing lower TSNA from potassium chloride applications, along with minimal effects on moisture and quality grade index, may cause the tobacco industry to reconsider the long-standing preference for potassium sulfate as the potassium source for tobacco production.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78621827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.3381/tobsci-d-20-00003
M. Richmond, R. Pearce, W. Bailey
Experiments were initiated in 2015 to evaluate the efficacy of chemical topping for burley tobacco (Nicotiana tabacum L.). The major objectives for this study were to determine the optimum timing of suckercide application and appropriate cultivar maturity for effective chemical topping. Burley tobacco cultivars TN 90 (medium maturity), KT 210, and KT 215 (late maturity) were chemically topped at the 10% button, 50% button, and 10% bloom growth stages. The 10% button and 50% button application timings were best suited for chemical topping practices. Treatments that targeted the 10% bloom stage did not completely halt inflorescence growth; however, all application timings resulted in excellent sucker control. Both medium and late maturing burley cultivars proved to be acceptable for chemical topping methods; however, timing the suckercide application may be less difficult with later maturing cultivars. Chemically topped treatments generally resulted in shorter, narrower tip leaves than manually topped treatments. There were no significant differences in total yield of TN 90 when comparing tobacco that was manually topped at 10% bloom to tobacco that was chemically topped at 10% button, 50% button, or 10% bloom across all environments. In 4 out of 6 environments, total yield was not significantly different between manual topping and any chemically topped application timing in the late maturing burley cultivars; however, at least 1 chemically topped application timing had equivalent yield to manually topped tobacco in all environments.
{"title":"The Effect of Suckercide Application Timing and Cultivar Maturity on Chemical Topping of Burley Tobacco","authors":"M. Richmond, R. Pearce, W. Bailey","doi":"10.3381/tobsci-d-20-00003","DOIUrl":"https://doi.org/10.3381/tobsci-d-20-00003","url":null,"abstract":"Experiments were initiated in 2015 to evaluate the efficacy of chemical topping for burley tobacco (Nicotiana tabacum L.). The major objectives for this study were to determine the optimum timing of suckercide application and appropriate cultivar maturity for effective chemical topping. Burley tobacco cultivars TN 90 (medium maturity), KT 210, and KT 215 (late maturity) were chemically topped at the 10% button, 50% button, and 10% bloom growth stages. The 10% button and 50% button application timings were best suited for chemical topping practices. Treatments that targeted the 10% bloom stage did not completely halt inflorescence growth; however, all application timings resulted in excellent sucker control. Both medium and late maturing burley cultivars proved to be acceptable for chemical topping methods; however, timing the suckercide application may be less difficult with later maturing cultivars. Chemically topped treatments generally resulted in shorter, narrower tip leaves than manually topped treatments. There were no significant differences in total yield of TN 90 when comparing tobacco that was manually topped at 10% bloom to tobacco that was chemically topped at 10% button, 50% button, or 10% bloom across all environments. In 4 out of 6 environments, total yield was not significantly different between manual topping and any chemically topped application timing in the late maturing burley cultivars; however, at least 1 chemically topped application timing had equivalent yield to manually topped tobacco in all environments.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77917916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.3381/tobsci-d-22-00002
M. Richmond, R. Pearce, T. Mark, W. Bailey
The act of topping tobacco (Nicotiana tabacum L.) involves the removal of the terminal bud or inflorescence of the tobacco plant. This practice ordinarily is accomplished by manually removing the top of each tobacco plant in an entire field, which is labor intensive and costly. The major objectives for this research were to determine which labeled suckercides could be used effectively for chemical topping of burley tobacco and the effect of suckercide rate on sucker control, yield, leaf quality, maleic hydrazide (MH) residues, and leaf chemistry. A study was initiated at Murray, Princeton, and Lexington, KY that investigated the efficacy of suckercide applications using combinations of MH, butralin, and fatty alcohols (FA). The terminal bud was not well controlled with FA or butralin alone, nor was adequate sucker control or total yield achieved. A significant reduction in total yield and sucker control were observed when plants were chemically topped with MH alone compared to manually topped or chemically topped with a tank mixture of MH and butralin at Princeton only. At the other locations, all chemically topped plants had similar yield to manually topped plants. Our data suggested that chemical topping of burley tobacco with a tank mixture of MH and a local systemic can be an acceptable alternative to manual topping as total yield and leaf quality grade index were not significantly different at any location. Total tobacco-specific nitrosamine (TSNA) content and MH residues were significantly lower with chemical topping treatments in some years and locations.
{"title":"The Effect of Suckercide Product and Application Rate on Chemical Topping of Burley Tobacco","authors":"M. Richmond, R. Pearce, T. Mark, W. Bailey","doi":"10.3381/tobsci-d-22-00002","DOIUrl":"https://doi.org/10.3381/tobsci-d-22-00002","url":null,"abstract":"The act of topping tobacco (Nicotiana tabacum L.) involves the removal of the terminal bud or inflorescence of the tobacco plant. This practice ordinarily is accomplished by manually removing the top of each tobacco plant in an entire field, which is labor intensive and costly. The major objectives for this research were to determine which labeled suckercides could be used effectively for chemical topping of burley tobacco and the effect of suckercide rate on sucker control, yield, leaf quality, maleic hydrazide (MH) residues, and leaf chemistry. A study was initiated at Murray, Princeton, and Lexington, KY that investigated the efficacy of suckercide applications using combinations of MH, butralin, and fatty alcohols (FA). The terminal bud was not well controlled with FA or butralin alone, nor was adequate sucker control or total yield achieved. A significant reduction in total yield and sucker control were observed when plants were chemically topped with MH alone compared to manually topped or chemically topped with a tank mixture of MH and butralin at Princeton only. At the other locations, all chemically topped plants had similar yield to manually topped plants. Our data suggested that chemical topping of burley tobacco with a tank mixture of MH and a local systemic can be an acceptable alternative to manual topping as total yield and leaf quality grade index were not significantly different at any location. Total tobacco-specific nitrosamine (TSNA) content and MH residues were significantly lower with chemical topping treatments in some years and locations.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74134992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.3381/tobsci-d-22-00003
M. Richmond, Colin Fisher, A. M. Fisher, R. Pearce, W. Bailey
Tobacco-specific nitrosamines (TSNAs) are known carcinogens in cured tobacco. They are produced primarily during the curing process, but agronomic practices occurring in the field as well as handling practices after curing may also influence TSNA levels, particularly if cured leaf is stored at high moisture. After curing and during market preparation, the cured leaf must be supple to avoid breakage. Ideally, this is after a period of wet weather during which the leaf absorbs moisture and comes into order or case. Often the weather remains dry for long periods after curing, and growers resort to artificial ordering to take down a sufficient amount of their crop to work on for several days, during which time the tobacco is bulked. The effect of this artificial ordering on TSNAs during short-term storage is not known. Field experiments were conducted in each of 3 years at two locations in Kentucky to evaluate TSNA accumulation following several ordering methods in dark air-cured and burley tobacco types. Treatments included natural ordering and variants of steaming and misting, which are both commonly used artificial ordering methods. At the Princeton location, samples were taken within 24 hr after the ordering treatments were done. In Lexington, samples were taken sequentially at takedown, after ordering, and after 14 d in the bulk. There were limited and inconsistent differences in total TSNAs between methods of ordering, and the TSNA levels were not affected by the moisture content of the leaf during bulking. There was a significant increase in TSNAs in the 24-hr period between takedown and bulking, which cannot be explained. We conclude that, in Kentucky, growers should use ordering methods that are best suited for their production system, but this may not be the case in warmer climates.
{"title":"Effect of Ordering Method on Tobacco-Specific Nitrosamines (TSNAs) Content in Dark Air-Cured and Burley Tobacco","authors":"M. Richmond, Colin Fisher, A. M. Fisher, R. Pearce, W. Bailey","doi":"10.3381/tobsci-d-22-00003","DOIUrl":"https://doi.org/10.3381/tobsci-d-22-00003","url":null,"abstract":"Tobacco-specific nitrosamines (TSNAs) are known carcinogens in cured tobacco. They are produced primarily during the curing process, but agronomic practices occurring in the field as well as handling practices after curing may also influence TSNA levels, particularly if cured leaf is stored at high moisture. After curing and during market preparation, the cured leaf must be supple to avoid breakage. Ideally, this is after a period of wet weather during which the leaf absorbs moisture and comes into order or case. Often the weather remains dry for long periods after curing, and growers resort to artificial ordering to take down a sufficient amount of their crop to work on for several days, during which time the tobacco is bulked. The effect of this artificial ordering on TSNAs during short-term storage is not known. Field experiments were conducted in each of 3 years at two locations in Kentucky to evaluate TSNA accumulation following several ordering methods in dark air-cured and burley tobacco types. Treatments included natural ordering and variants of steaming and misting, which are both commonly used artificial ordering methods. At the Princeton location, samples were taken within 24 hr after the ordering treatments were done. In Lexington, samples were taken sequentially at takedown, after ordering, and after 14 d in the bulk. There were limited and inconsistent differences in total TSNAs between methods of ordering, and the TSNA levels were not affected by the moisture content of the leaf during bulking. There was a significant increase in TSNAs in the 24-hr period between takedown and bulking, which cannot be explained. We conclude that, in Kentucky, growers should use ordering methods that are best suited for their production system, but this may not be the case in warmer climates.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87906732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.3381/tobsci-d-20-00008
M. M. Short, M. Vann, D. Suchoff
Organically derived fatty alcohol is useful for the control of tobacco axillary buds (suckers) and is greatly needed by commercial organic tobacco farmers. Recently, its approval by the U.S. Department of Agriculture (USDA)-National Organic Program has been scrutinized. The objective of this research was to evaluate the suggested alternatives: pelargonic acid, vegetable oil, canola oil, and peppermint + spearmint oil using two different application methods, a standard 3-nozzle boom or a dropline. Chemical injury was not observed within any treatment except for those containing pelargonic acid. Injury was greatest when applied with the 3-nozzle boom and was reduced by nearly 50% with the dropline; however, injury after the dropline application was 2.5 to 7 times greater than any other treatment. Despite significant injury, sucker control was acceptable with pelargonic acid (≈90%) and was similar to that resulting from fatty alcohol (99–100%). Sucker control was <40% among all other treatments, with peppermint + spearmint oil providing better efficacy than canola (10 to 15%) or vegetable oil (−1 to −10%). Cured leaf yield, quality, and value were likewise greatest in fatty alcohol treatments because of maximized sucker control and minimized chemical injury. Producers are encouraged to utilize fatty alcohol until the alternative products can be reformulated and re-evaluated.
{"title":"Organic Sucker Control: Screening Different Active Ingredients for Commercial Application","authors":"M. M. Short, M. Vann, D. Suchoff","doi":"10.3381/tobsci-d-20-00008","DOIUrl":"https://doi.org/10.3381/tobsci-d-20-00008","url":null,"abstract":"Organically derived fatty alcohol is useful for the control of tobacco axillary buds (suckers) and is greatly needed by commercial organic tobacco farmers. Recently, its approval by the U.S. Department of Agriculture (USDA)-National Organic Program has been scrutinized. The objective of this research was to evaluate the suggested alternatives: pelargonic acid, vegetable oil, canola oil, and peppermint + spearmint oil using two different application methods, a standard 3-nozzle boom or a dropline. Chemical injury was not observed within any treatment except for those containing pelargonic acid. Injury was greatest when applied with the 3-nozzle boom and was reduced by nearly 50% with the dropline; however, injury after the dropline application was 2.5 to 7 times greater than any other treatment. Despite significant injury, sucker control was acceptable with pelargonic acid (≈90%) and was similar to that resulting from fatty alcohol (99–100%). Sucker control was <40% among all other treatments, with peppermint + spearmint oil providing better efficacy than canola (10 to 15%) or vegetable oil (−1 to −10%). Cured leaf yield, quality, and value were likewise greatest in fatty alcohol treatments because of maximized sucker control and minimized chemical injury. Producers are encouraged to utilize fatty alcohol until the alternative products can be reformulated and re-evaluated.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90600907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.3381/tobsci-d-22-00001
D. Suchoff, M. Vann, M. McGinnis, J. H. Mason, L. Fisher
Certified organic flue-cured tobacco (Nicotiana tabacum L.) production has experienced significant expansion in the United States. Despite this expansion, there is very little information available that outlines organic nitrogen (N) programs for seedling production. To develop grower recommendations, research was conducted to evaluate the effects of a Peruvian seabird guano (SG), sodium nitrate (SN), or a combination of the two (SN_SG) in a float system on float water chemistry and seedling vigor. A conventional treatment (Conv; SQM Ultrasol Premium) was included for comparison. A greenhouse study was conducted twice between June 2016 and January 2017. Nitrogen fertilizer treatments were applied to tobacco float system water twice during the germination and growth of tobacco transplants. Float system water was collected every 5 days and analyzed for N forms, pH, dissolved oxygen, and bicarbonate. At the end of each experiment, transplant dimensions were measured and percent of usable plants collected. Float water bicarbonate concentration was <1 meq L−1 in treatments absent of SG for the duration of the study, but were in excess of 12 meq L−1 25 days after seeding (DAS) when SG was the exclusive N source. Despite high ammonium and bicarbonate concentrations with SG, neither factor negatively impacted seedling growth. Both SG and SN_SG produced as many usable plants as Conv; however, seedling height and diameter tended to be lower in SG compared to the other two treatments. No usable transplants were produced when SN was the sole fertility source, likely because of lack of nutrients other than N. Furthermore, many of the organic fertility products require biological activity to mineralize organic N to a plant-available form. This activity can have potentially detrimental outcomes on float system solution pH, dissolved oxygen, and bicarbonate levels.
{"title":"Nitrogen Fertilizer Programs for Organic Flue-Cured Tobacco (Nicotiana Tabacum L.) Seedling Production","authors":"D. Suchoff, M. Vann, M. McGinnis, J. H. Mason, L. Fisher","doi":"10.3381/tobsci-d-22-00001","DOIUrl":"https://doi.org/10.3381/tobsci-d-22-00001","url":null,"abstract":"Certified organic flue-cured tobacco (Nicotiana tabacum L.) production has experienced significant expansion in the United States. Despite this expansion, there is very little information available that outlines organic nitrogen (N) programs for seedling production. To develop grower recommendations, research was conducted to evaluate the effects of a Peruvian seabird guano (SG), sodium nitrate (SN), or a combination of the two (SN_SG) in a float system on float water chemistry and seedling vigor. A conventional treatment (Conv; SQM Ultrasol Premium) was included for comparison. A greenhouse study was conducted twice between June 2016 and January 2017. Nitrogen fertilizer treatments were applied to tobacco float system water twice during the germination and growth of tobacco transplants. Float system water was collected every 5 days and analyzed for N forms, pH, dissolved oxygen, and bicarbonate. At the end of each experiment, transplant dimensions were measured and percent of usable plants collected. Float water bicarbonate concentration was <1 meq L−1 in treatments absent of SG for the duration of the study, but were in excess of 12 meq L−1 25 days after seeding (DAS) when SG was the exclusive N source. Despite high ammonium and bicarbonate concentrations with SG, neither factor negatively impacted seedling growth. Both SG and SN_SG produced as many usable plants as Conv; however, seedling height and diameter tended to be lower in SG compared to the other two treatments. No usable transplants were produced when SN was the sole fertility source, likely because of lack of nutrients other than N. Furthermore, many of the organic fertility products require biological activity to mineralize organic N to a plant-available form. This activity can have potentially detrimental outcomes on float system solution pH, dissolved oxygen, and bicarbonate levels.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83910108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fernanda F Zenkner, M. Margis-Pinheiro, Alexandro Cagliari
Alkaloids are important compounds found in Nicotiana plants, essential in plant defense against herbivores. The main alkaloid of Nicotiana tabacum, nicotine, is produced in roots and translocated to the leaves. Nicotine is formed by a pyrrolidine and a pyridine ring in a process involving several enzymes. The pyridine ring of nicotine is derived from nicotinic acid, whereas the pyrrolidine ring originates from polyamine putrescine metabolism. After synthesis in root cortical cells, a set of transporters is known to transport nicotine upward to the aerial part and store it in leaf vacuoles. Moreover, nicotine can be metabolized in leaves, giving rise to nornicotine through the N-demethylation process. Some Nicotiana wild species produce acyltransferase enzymes, which allow the plant to make N-acyl-nornicotine, an alkaloid with more potent insecticidal properties than nicotine. However, although we can find a wealth of information about the alkaloid production in Nicotiana spp., our understanding about nicotine biosynthesis, transport, and metabolism is still incomplete. This review will summarize these pathways on the basis on recent literature, as well as highlighting questions that need further investigation.
{"title":"Nicotine Biosynthesis inNicotiana: A Metabolic Overview","authors":"Fernanda F Zenkner, M. Margis-Pinheiro, Alexandro Cagliari","doi":"10.3381/18-063","DOIUrl":"https://doi.org/10.3381/18-063","url":null,"abstract":"Alkaloids are important compounds found in Nicotiana plants, essential in plant defense against herbivores. The main alkaloid of Nicotiana tabacum, nicotine, is produced in roots and translocated to the leaves. Nicotine is formed by a pyrrolidine and a pyridine ring in a process involving several enzymes. The pyridine ring of nicotine is derived from nicotinic acid, whereas the pyrrolidine ring originates from polyamine putrescine metabolism. After synthesis in root cortical cells, a set of transporters is known to transport nicotine upward to the aerial part and store it in leaf vacuoles. Moreover, nicotine can be metabolized in leaves, giving rise to nornicotine through the N-demethylation process. Some Nicotiana wild species produce acyltransferase enzymes, which allow the plant to make N-acyl-nornicotine, an alkaloid with more potent insecticidal properties than nicotine. However, although we can find a wealth of information about the alkaloid production in Nicotiana spp., our understanding about nicotine biosynthesis, transport, and metabolism is still incomplete. This review will summarize these pathways on the basis on recent literature, as well as highlighting questions that need further investigation.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84896509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With rising input costs, flue-cured tobacco producers must consider modern fertility programs that focus on reduced application rates of alternative nutrient sources. To demonstrate the usability o...
{"title":"VERIFICATION OF NITROGEN AND PHOSPHORUS APPLICATION RATES TO FLUE-CURED TOBACCO","authors":"M. Vann, L. Fisher","doi":"10.3381/17-061","DOIUrl":"https://doi.org/10.3381/17-061","url":null,"abstract":"With rising input costs, flue-cured tobacco producers must consider modern fertility programs that focus on reduced application rates of alternative nutrient sources. To demonstrate the usability o...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81918863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
From 2013 to 2015, research was conducted to estimate the maximum expected residue levels for the insecticides cyantraniliprole and spinosad following application to flue-cured tobacco. Data were generated in order to assist industry in establishing Guidance Residue Limits for both compounds. The insecticides were applied to fields of tobacco at maximum rates in accordance with the labeled rates and the harvested/cured leaf was analyzed in a lab for chemical residues. The findings indicated that the expected residues on cured leaf would be low or not quantifiable under existing detection techniques.
{"title":"CYANTRANILIPROLE AND SPINOSAD RESIDUES IN FLUE-CURED TOBACCO","authors":"M. Vann, and L.R. Fisher, D. S. Whitley","doi":"10.3381/17-059","DOIUrl":"https://doi.org/10.3381/17-059","url":null,"abstract":"From 2013 to 2015, research was conducted to estimate the maximum expected residue levels for the insecticides cyantraniliprole and spinosad following application to flue-cured tobacco. Data were generated in order to assist industry in establishing Guidance Residue Limits for both compounds. The insecticides were applied to fields of tobacco at maximum rates in accordance with the labeled rates and the harvested/cured leaf was analyzed in a lab for chemical residues. The findings indicated that the expected residues on cured leaf would be low or not quantifiable under existing detection techniques.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89548567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Significant variability in cured-leaf tobacco-specific nitrosamine (TSNA) content is commonly observed when sampling within dark air-curing barns. This variability may be due to inconsistency in th...
{"title":"Analysis of Variability in Curing Conditions and Tobacco-Specific Nitrosamines Within Barns of Dark Air-Cured Tobacco","authors":"M. Richmond, R. Pearce, B. Goff, W. Bailey","doi":"10.3381/17-060","DOIUrl":"https://doi.org/10.3381/17-060","url":null,"abstract":"Significant variability in cured-leaf tobacco-specific nitrosamine (TSNA) content is commonly observed when sampling within dark air-curing barns. This variability may be due to inconsistency in th...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89355303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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