Pub Date : 2000-01-01DOI: 10.3381/0082-4623-44.1.27
L. Reynolds
Abstract The effects of bicarbonate (HCO3−) concentrations on the production of flue-cured tobacco seedlings in a direct-seeded float greenhouse system were investigated and compared to seedlings produced in muck seedbeds over a three-year period. The HCO3− concentrations used (0, 100, 200, 400, and 800 mg/L) were created and maintained at the desired levels by acidification with H2SO4 or by addition of NaHCO3 to tanks containing 100 L of fertilized groundwater. Each 100 L tank (treatment) contained four 253-cell foam trays and was located in a heated and forced-air ventilated double-poly greenhouse maintained at 15° to 30°C. Excellent quality seedlings were produced in all treatments except the 800 mg/L HCO3−. Initial nutrient solution pH varied with HCO3− concentration and declined linearly with time for all treatments. Initial plug media pH also varied with HCO3− concentration; pH increased for about 25 d then declined to a level just above that of the nutrient solution pH. Changes in solution and plug...
{"title":"NUTRIENT SOLUTION BICARBONATE CONCENTRATION EFFECTS ON GROWTH MEDIA pH, ELECTRICAL CONDUCTIVITY, AND ON FLUE-CURED TOBACCO YIELD AND QUALITY FOR TRANSPLANTS PRODUCED IN A HEATED GREENHOUSE IN A DIRECT-SEEDED FLOAT SYSTEM","authors":"L. Reynolds","doi":"10.3381/0082-4623-44.1.27","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.27","url":null,"abstract":"Abstract The effects of bicarbonate (HCO3−) concentrations on the production of flue-cured tobacco seedlings in a direct-seeded float greenhouse system were investigated and compared to seedlings produced in muck seedbeds over a three-year period. The HCO3− concentrations used (0, 100, 200, 400, and 800 mg/L) were created and maintained at the desired levels by acidification with H2SO4 or by addition of NaHCO3 to tanks containing 100 L of fertilized groundwater. Each 100 L tank (treatment) contained four 253-cell foam trays and was located in a heated and forced-air ventilated double-poly greenhouse maintained at 15° to 30°C. Excellent quality seedlings were produced in all treatments except the 800 mg/L HCO3−. Initial nutrient solution pH varied with HCO3− concentration and declined linearly with time for all treatments. Initial plug media pH also varied with HCO3− concentration; pH increased for about 25 d then declined to a level just above that of the nutrient solution pH. Changes in solution and plug...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"15 1","pages":"27-34"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83726481","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.65
L. Caruso, R. Pearce, F. Fannin, L. Bush
Abstract The nutrient solution in the tobacco-transplant float system is not usually circulated or aerated, and may thus become stagnant and deficient in oxygen. In this system, plants produce media, water and spiral roots. The metabolic activity of these root types during seedling development was investigated in a standard float system and under a low oxygen (near-anaerobic) regime. Oxygen consumption by tobacco seedling root tips was measured using a microsensor. The effects of near-anaerobic conditions on seedling development in a float system reduced dry matter accumulation of both media and water roots. Media roots and spiral roots had a similar metabolic activity rate, and a much greater rate of oxygen uptake than did water roots. The near-anaerobic condition in the float system was less deleterious to media roots than water roots.
{"title":"METABOLIC ACTIVITY OF FLOAT-TOBACCO TRANSPLANT ROOTS1","authors":"L. Caruso, R. Pearce, F. Fannin, L. Bush","doi":"10.3381/0082-4623-44.1.65","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.65","url":null,"abstract":"Abstract The nutrient solution in the tobacco-transplant float system is not usually circulated or aerated, and may thus become stagnant and deficient in oxygen. In this system, plants produce media, water and spiral roots. The metabolic activity of these root types during seedling development was investigated in a standard float system and under a low oxygen (near-anaerobic) regime. Oxygen consumption by tobacco seedling root tips was measured using a microsensor. The effects of near-anaerobic conditions on seedling development in a float system reduced dry matter accumulation of both media and water roots. Media roots and spiral roots had a similar metabolic activity rate, and a much greater rate of oxygen uptake than did water roots. The near-anaerobic condition in the float system was less deleterious to media roots than water roots.","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"1 1","pages":"65-70"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88673032","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.41
B. Maw, J. Moore, M. G. Stephenson, P. Sumner, E. Tollner
Abstract Tobacco was stored in small bales of volume 0.05m3 with dimensions 30 × 30 × 60 cm in 1996 and 38 × 38 × 38 cm in 1997 and 1998. Treatments were arranged in a factorial of three densities ...
{"title":"PHYSICAL RESPONSES OF FLUE-CURED TOBACCO STORED IN THE FORM OF BALES1,2","authors":"B. Maw, J. Moore, M. G. Stephenson, P. Sumner, E. Tollner","doi":"10.3381/0082-4623-44.1.41","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.41","url":null,"abstract":"Abstract Tobacco was stored in small bales of volume 0.05m3 with dimensions 30 × 30 × 60 cm in 1996 and 38 × 38 × 38 cm in 1997 and 1998. Treatments were arranged in a factorial of three densities ...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"42 1","pages":"41-50"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85324020","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.59
D. Bowman, V. Sisson
Abstract Breeding of flue-cured tobacco began in the United States as farmers made selections and reselections of existing cultivars. Organized tobacco breeding began in 1928 with Coker Pedigreed Seed Company. Other major seed companies involved in U.S. tobacco breeding were McNair Seed Company and Speight Seed Farms. Several smaller companies also existed for short periods of time. The patriarch of flue-cured tobacco breeders was Dr. Hoyt Rogers, who contributed to standardization of cultivars and yield improvements. In the past, prominent individuals in both the private and public sectors were instrumental in improving disease resistance, the primary focus of flue-cured tobacco breeding since the 1930s. Currently, tobacco companies R.J. Reynolds, Universal Leaf, and U.S. Tobacco are involved in breeding. Public breeding is limited to North Carolina, Virginia, and South Carolina, while there are six private breeding companies. Flue-cured tobacco breeding at present is a vibrant activity, but it faces pol...
{"title":"A HISTORICAL OVERVIEW OF FLUE-CURED TOBACCO BREEDING IN THE U.S.A","authors":"D. Bowman, V. Sisson","doi":"10.3381/0082-4623-44.1.59","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.59","url":null,"abstract":"Abstract Breeding of flue-cured tobacco began in the United States as farmers made selections and reselections of existing cultivars. Organized tobacco breeding began in 1928 with Coker Pedigreed Seed Company. Other major seed companies involved in U.S. tobacco breeding were McNair Seed Company and Speight Seed Farms. Several smaller companies also existed for short periods of time. The patriarch of flue-cured tobacco breeders was Dr. Hoyt Rogers, who contributed to standardization of cultivars and yield improvements. In the past, prominent individuals in both the private and public sectors were instrumental in improving disease resistance, the primary focus of flue-cured tobacco breeding since the 1930s. Currently, tobacco companies R.J. Reynolds, Universal Leaf, and U.S. Tobacco are involved in breeding. Public breeding is limited to North Carolina, Virginia, and South Carolina, while there are six private breeding companies. Flue-cured tobacco breeding at present is a vibrant activity, but it faces pol...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"23 1","pages":"59-64"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89476252","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.7
L. Wells, T. Bridges, T. D. Smith
Abstract A computerized analysis has been conducted to determine the comparative annual costs of various harvesting/market preparation systems for burley tobacco. The CATCH223 model developed at the University of Kentucky computes the annual costs of alternative systems that facilitate harvesting and/or market preparation at a time rate(s) prescribed by a producer or analyst. Harvesting systems that utilized the most manual labor had the lowest annual costs for crop sizes analyzed between 4 and 40 ha, although the advantage of manual vs mechanized systems diminished as crop size increased. On the other hand, the analysis shows that mechanized market preparation systems have consistently lower annual costs than conventional methods that require manual removal and grading of cured leaves. Finally, the analysis shows that a fully automated harvesting system (having the highest projected annual cost of all of the alternatives) can be combined with an automated market preparation system resulting in a total an...
{"title":"SYNERGISTIC AUTOMATION IN BURLEY HARVESTING AND MARKET PREPARATION1","authors":"L. Wells, T. Bridges, T. D. Smith","doi":"10.3381/0082-4623-44.1.7","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.7","url":null,"abstract":"Abstract A computerized analysis has been conducted to determine the comparative annual costs of various harvesting/market preparation systems for burley tobacco. The CATCH223 model developed at the University of Kentucky computes the annual costs of alternative systems that facilitate harvesting and/or market preparation at a time rate(s) prescribed by a producer or analyst. Harvesting systems that utilized the most manual labor had the lowest annual costs for crop sizes analyzed between 4 and 40 ha, although the advantage of manual vs mechanized systems diminished as crop size increased. On the other hand, the analysis shows that mechanized market preparation systems have consistently lower annual costs than conventional methods that require manual removal and grading of cured leaves. Finally, the analysis shows that a fully automated harvesting system (having the highest projected annual cost of all of the alternatives) can be combined with an automated market preparation system resulting in a total an...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"11 1","pages":"7-10"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84761034","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.71
B. Rodu, B. Ou
Abstract Mammalian cells have evolved a complex network of enzymatic and non-enzymatic molecules that protect them from the detrimental effects of reactive oxygen species (ROS). These endogenous antioxidant agents are supplemented by dietary antioxidants, obtained mainly from plants. Although many studies have assessed the antioxidant properties of fruits and vegetables, much less is known about the antioxidant characteristics of another commonly ingested plant product, tobacco. The antioxidant properties of 16 commercially available tobacco products were determined using an oxygen radical absorbance capacity (ORAC) assay. The concentrations of polyphenols in these products also were determined. The tobacco products tested had a range of antioxidant activity from modest to high. A significant linear relationship was observed between the overall antioxidant capacity and total phenolic content. The high antioxidant activity in smokeless tobacco may partially explain the low cancer risk associated with long-...
{"title":"THE ANTIOXIDANT PROPERTIES OF TOBACCO","authors":"B. Rodu, B. Ou","doi":"10.3381/0082-4623-44.1.71","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.71","url":null,"abstract":"Abstract Mammalian cells have evolved a complex network of enzymatic and non-enzymatic molecules that protect them from the detrimental effects of reactive oxygen species (ROS). These endogenous antioxidant agents are supplemented by dietary antioxidants, obtained mainly from plants. Although many studies have assessed the antioxidant properties of fruits and vegetables, much less is known about the antioxidant characteristics of another commonly ingested plant product, tobacco. The antioxidant properties of 16 commercially available tobacco products were determined using an oxygen radical absorbance capacity (ORAC) assay. The concentrations of polyphenols in these products also were determined. The tobacco products tested had a range of antioxidant activity from modest to high. A significant linear relationship was observed between the overall antioxidant capacity and total phenolic content. The high antioxidant activity in smokeless tobacco may partially explain the low cancer risk associated with long-...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"44 1","pages":"71-73"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73773391","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.1
G. Hoyt
Abstract Maintaining soil productivity on land cropped to burley tobacco (Nicotiana tabacum L.) requires management practices that conserve surface soil and retain high soil nitrogen (N) availabili...
{"title":"THE EFFECTS OF TILLAGE SYSTEMS ON BURLEY TOBACCO YIELD AND NITROGEN UPTAKE PATTERNS","authors":"G. Hoyt","doi":"10.3381/0082-4623-44.1.1","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.1","url":null,"abstract":"Abstract Maintaining soil productivity on land cropped to burley tobacco (Nicotiana tabacum L.) requires management practices that conserve surface soil and retain high soil nitrogen (N) availabili...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"42 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82462278","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.35
J. Hermann, R. Hayes, T. Mueller
Abstract Degradation of flumetralin and pendimethalin in soil was examined under controlled environmental conditions. A complete factorial arrangement of four soils (representing the major tobacco production regions), two temperatures (15 and 30°C), and two soil moisture contents were examined. Additionally, the persistence of each herbicide was examined alone and in the presence of the other herbicide from 0 to 180 d. Soil moisture had a minor effect on flumetralin and pendimethalin degradation, but higher temperature encouraged herbicide degradation. Soil type had a major influence, as pendimethalin degradation was negatively correlated to both soil pH and clay content. This research indicated that both pendimethalin and flumetralin have the potential to persist in the environment for a time interval sufficient to affect subsequently planted small grain cover crops. Flumetralin half-life at 30°C was >180 d in all four soils. Given the use pattern of pendimethalin in tobacco, this research indicated that...
{"title":"PENDIMETHALIN AND FLUMETRALIN DEGRADATION UNDER CONTROLLED CONDITIONS IN FOUR SOILS","authors":"J. Hermann, R. Hayes, T. Mueller","doi":"10.3381/0082-4623-44.1.35","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.35","url":null,"abstract":"Abstract Degradation of flumetralin and pendimethalin in soil was examined under controlled environmental conditions. A complete factorial arrangement of four soils (representing the major tobacco production regions), two temperatures (15 and 30°C), and two soil moisture contents were examined. Additionally, the persistence of each herbicide was examined alone and in the presence of the other herbicide from 0 to 180 d. Soil moisture had a minor effect on flumetralin and pendimethalin degradation, but higher temperature encouraged herbicide degradation. Soil type had a major influence, as pendimethalin degradation was negatively correlated to both soil pH and clay content. This research indicated that both pendimethalin and flumetralin have the potential to persist in the environment for a time interval sufficient to affect subsequently planted small grain cover crops. Flumetralin half-life at 30°C was >180 d in all four soils. Given the use pattern of pendimethalin in tobacco, this research indicated that...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"26 1","pages":"35-40"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78724721","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 : 2000-01-01DOI: 10.3381/0082-4623-44.1.51
Y. Abubakar, J. H. Young, W. Johnson, W. Weeks
Abstract The present study represents a portion of an effort to develop mathematical models for predicting changes in moisture and chemical composition of flue-cured tobacco during curing. In two experiments, concentrations of chlorophyll, starch, reducing sugars, and total alkaloids (as well as moisture contents) were measured. In the first experiment, tobacco was yellowed at temperatures of 30°C, 35°C, and 40°C with 3.33°C wet-bulb depression. In the second experiment, tobacco was yellowed at 35°C with wet-bulb depressions of 1.67°C, 3.33°C, and 5°C (or approximately 89, 81, and 70% relative humidity, respectively). In general, concentrations of chlorophyll and starch in the leaves decreased during curing, whereas concentrations of reducing sugars increased, and total alkaloids remained relatively unchanged. Yellowing temperature had no significant effect on moisture content at the end of the yellowing and leaf drying stages, nor on chlorophyll at the end of the yellowing stage and starch at the end of ...
{"title":"CHANGES IN MOISTURE AND CHEMICAL COMPOSITION OF FLUE-CURED TOBACCO DURING CURING1","authors":"Y. Abubakar, J. H. Young, W. Johnson, W. Weeks","doi":"10.3381/0082-4623-44.1.51","DOIUrl":"https://doi.org/10.3381/0082-4623-44.1.51","url":null,"abstract":"Abstract The present study represents a portion of an effort to develop mathematical models for predicting changes in moisture and chemical composition of flue-cured tobacco during curing. In two experiments, concentrations of chlorophyll, starch, reducing sugars, and total alkaloids (as well as moisture contents) were measured. In the first experiment, tobacco was yellowed at temperatures of 30°C, 35°C, and 40°C with 3.33°C wet-bulb depression. In the second experiment, tobacco was yellowed at 35°C with wet-bulb depressions of 1.67°C, 3.33°C, and 5°C (or approximately 89, 81, and 70% relative humidity, respectively). In general, concentrations of chlorophyll and starch in the leaves decreased during curing, whereas concentrations of reducing sugars increased, and total alkaloids remained relatively unchanged. Yellowing temperature had no significant effect on moisture content at the end of the yellowing and leaf drying stages, nor on chlorophyll at the end of the yellowing stage and starch at the end of ...","PeriodicalId":10257,"journal":{"name":"Chinese Tobacco Science","volume":"122 1","pages":"51-58"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89261107","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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