Browsing by Author "Jones, James L."
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- Covers for producing tobacco transplantsJones, James L. (Virginia Cooperative Extension Service, 1977-11)Tobacco transplants can be successfully produced under various types of covers, providing good management practices are followed.
- Development of a Greenhouse Tobacco Seedling Performance IndexClarke, Jodie Johnson (Virginia Tech, 2001-05-02)Tobacco seed performance is traditionally measured as percentage germination at 14 d under controlled laboratory conditions. However, under greenhouse conditions, seed lots with equal 14-d germination may exhibit substantial differences in uniformity of early seedling growth and spiral root incidence that impact the number of usable transplants. A seedling performance index (SPI) was developed to quantitatively describe greenhouse tobacco seedling performance. The 14-d emergence, relative leaf area uniformity, and seedling leaf area determined by computer image analysis were used to calculate the index. Greenhouse tobacco seed trials demonstrated that seed with the Rickard pellet had higher emergence, but the higher spiral root incidence associated with the Rickard pellet lowered the SPI compared to the Cross Creek pellet. Primed seed lots of flue-cured cultivars (NC 72 and NC 71) had a significantly higher SPI than the nonprimed seed lots at one location but not at a second location. Seed lots sown in Premier Pro-Mix TA commercial medium had a higher spiral root incidence, which resulted in a lower SPI compared to Carolina Choice, Carolina Gold, and Sunshine LP5 commercial media. The index quantitatively determined differences in seedling performance under greenhouse conditions not reflected by standard germination tests. Significant differences in the SPI were observed among seed lots with certified 90% germination. The SPI is a simple method to describe seedling performance because the data used to calculate the SPI is obtained from one seed tray image. In contrast, frequent counting and seedling evaluations are involved with standard germination and vigor tests.
- Fire-cured tobacco variety information for 1976Jones, James L.; Terrill, T. R. (Virginia Cooperative Extension Service, 1975-11)Presents information that may be helpful in choosing the best varieties of fire-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1975Terrill, T. R.; Jones, James L.; Rogers, M. J. (Virginia Cooperative Extension Service, 1974-12)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1976Terrill, T. R.; Jones, James L.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1975-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1977Terrill, T. R.; Jones, James L.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1976-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1978Terrill, T. R.; Jones, James L.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1977-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1979Terrill, T. R.; Jones, James L.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1978-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1980Jones, James L.; Terrill, T. R.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1979-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco variety information for 1981Jones, James L.; Terrill, T. R.; Rogers, M. J.; Reilly, J. J. (Virginia Cooperative Extension Service, 1980-11)Presents information that may be helpful in choosing the best varieties of flue-cured tobacco to meet specific production goals.
- Flue-cured tobacco: alternative management systemsClarke, C. Taylor Jr. (Virginia Tech, 1996-05-05)The United States share of the exported flue-cured tobacco market has decreased over the last decade as other countries have increased production of improved quality tobacco. Such tobacco is available at a substantially lower price than U. S. tobacco and thus desirable for the manufacture of less expensive discount cigarettes. Although world consumption of American style cigarettes is increasing, demand is not sufficient to maintain current production levels of premium quality U. S. flue-cured tobacco. Production systems that increase yields of suitable quality tobacco for discount cigarette manufacture without increasing production costs would allow tobacco to be offered competitively on the world market while maintaining current income. A study of ten management systems was conducted evaluating the influence of plant spacing, topping height, and harvest method on yield and quality of flue-cured tobacco. Leaf populations of 538,000/ha harvested once-over resulted in a 6.5%, 11.0%, 6.0%, and 13.5% increase in yield, value, price, and grade index, respectively, compared to the standard treatment. An expert panel showed no preference among systems and judged all systems acceptable in quality. A study conducted as a randomized complete block in a split plot arrangement evaluated the influence of row spacing and plant spacing on the yield and quality of flue-cured tobacco harvested once-over. Yield, value, and grade index increased while price per kg was unchanged as plant population increased. Flue-cured tobacco harvested in a single harvest produced cured leaf of acceptable quality; however, increased leaf populations are required to maintain acceptable yields.
- Impact of Conservation Tillage on Soil Erosion and the Agronomic Performance of Flue-Cured TobaccoJones, Bruce (Virginia Tech, 1998-12-08)Conservation tillage tobacco production has gained little producer acceptance since introduction in the late 1960's. Yield reductions, tobacco quality issues, unacceptable weed control, and inadequate planting equipment limited practice adoption and substantiated the need for continued research. The recent developments of a Subsurface Tiller-TransplanterTM and the herbicide SpartanTM renewed producer interest in conservation tillage and led to an investigation with both flue-cured and Virginia dark-fired tobacco. Flue-cured tobacco was transplanted into rye mulch on bedded rows and subsequently cultivated at various timings. Conservation tillage significantly reduced soil erosion approximately 92 percent and tobacco yield approximately 23 percent when row cultivation was not applied. Row cultivation significantly increased tobacco yield without increasing soil erosion. The yield of conservation tillage tobacco receiving a minimum of two cultivations was similar to conventional tobacco. The second study evaluated wheat, rye, crimson clover, and mixtures of crimson clover with either wheat or rye as cover crop mulches for conservation tillage production of Virginia dark-fired tobacco. Conservation tillage, regardless of cover crop, reduced dark-fired tobacco yields approximately 779 and 488 pounds per acre in 1996 and 1997, respectively. The removal of cover crop residue for hay did not lower tobacco yield compared to leaving residue on the soil surface. Row cultivation increased conservation tillage tobacco yield approximately 247 pounds in 1997 regardless of cover crop. The nitrogen contribution of crimson clover was minimal in both years of the study and did not affect tobacco performance.
- Influence of ethephon on growth and flowering of flue-cured tobaccoFowlkes, Donald James (Virginia Polytechnic Institute and State University, 1985)Tobacco (Nicotiana tabacum L.) leaf initiation stops when floral induction is completed. Floral induction (an internal biochemical change which signals development of flowers) can occur prematurely, during the pre- and/or post-transplant environment. Plants which flower prematurely have few leaves and low yields. Removal of the influorescence on these plants will break apical dominance and allow production of additional leaves from axillary bud. This practice requires additional labor and increases production costs. Objectives of this study were to 1) determine how application timing, rate, localization, and on-plant duration of ethephon (2-chloroethylphosphonic acid) influences growth and flowering of flue-cured ‘NC 82’ tobacco; 2) examine the relationship between temperatures in the seedling environment and premature flowering and determine how time of plant bed cover removal affects premature flowering; and 3) quantify the ethylene released from buds, leaves, stems, and roots of tobacco seedlings at various days after application of ethephon. Ethephon applied to flue-cured tobacco seedlings before the completion of floral induction significantly reduced premature flowering and increased days to flower, number of leaf nodes per plant, and yield. Multiple applications and increased rates of ethephon did not increase the number of leaf nodes beyond the level obtained from a single application of 960 mg L⁻¹ ethephon solution applied at the rate of 44 mL m⁻² of plant bed. In wash-off studies, maximum benefit was obtained when ethephon remained on the seedlings one to two hours after application. In localization studies, increases in number of leaf nodes per plant were not different when 0.09 and 0.51 mg of ethephon was applied to the bud and largest leaf, respectively. Ethylene released from ethephon-treated greenhouse seedlings remained detectable four weeks after treatment. On-farm test locations with the two highest percentages of premature flowering had the lowest average daily minimum temperatures during the pretransplant period. Premature flowering was significantly increased at two of seven locations by removal of the perforated plastic plant bed covers two weeks compared to one week before transplanting. Floral induction of tobacco seedlings in controlled pretransplant environments was obtained by continuous 15°C temperature and 8 h photoperiods for 3 weeks.
- Influence of nitrogen rate, harvest frequency, lower leaf management, and chemical topping on mammoth cultivars of flue-cured tobaccoLong, Robert Sherman (Virginia Tech, 1989-05-15)Mammoth cultivars of tobacco do not flower under normal production conditions. A field management system must be devised for these cultivars to optimize agronomic traits and chemical constituents of the cured leaf. Field experiments were conducted at the Southern Piedmont Agricultural Experiment Station near Blackstone, Virginia in 1987 and 1988 to determine the influence of nitrogen rate, harvest frequency, and time and number of basal leaf removal on several agronomic and chemical properties of a mammoth cultivar of flue-cured tobacco. The feasibility of chemically topping two mammoth cultivars was also investigated. Increasing nitrogen rates increased values per hectere by $176 and total alkaloids by 0.5% in 1987. Increasing the number of harvest increased percentage lugs (X) and reducing sugars for stalk position B in 1988 but decreased reducing sugars for stalk positions A and C in 1988. Delaying leaf removal increased yield and values per hectare by 141 kg ha⁻¹ and $84, respectively, and decreased lug production in 1987 and 1988. Total alkaloids decreased by 0.7% with delayed leaf removal in 1987. Delayed leaf removal increased reducing sugars at stalk position A by 2% in 1988. Removing fewer basal leaves increased yields by 115 kg ha⁻¹, values per hectare, and percentage smoking leaf (H) for both years. Alkaloids for stalk position B increased with fewer basal leaves removed in 1988. Decreased basal leaf removal decreased plant height by 9 cm, percentage leaf (B), and reducing sugars in stalk positions A, B, and D in 1988. Delaying basal leaf removal and decreasing harvest frequency increased the percentage of cutters (C). Percentage smoking leaf increased with nitrogen rate and removal of fewer basal leaves. Chemical topping created taller plants with more leaves, narrower tip leaves, lower total alkaloids, and equal or higher reducing sugars relative to hand topping. Tip leaves from chemically topped plants were 6 to 8 cm shorter than hand-topped plants in 1987. Maleic hydrazide treatments resulted in 429 to 700 kg ha⁻¹ lower yields and lower values than hand topping and 6 more suckers than all other treatments. The fatty alcohol / maleic hydrazide treatment produced 380 kg ha⁻¹ higher yields and grade indices lower than the hand-topped control in 1987. Above normal nitrogen rate, 3 or 5 time harvest, removal of 4 to 6 leaves at topping or via senescence, and chemical topping with Prime+ or fatty alcohol / maleic hydrazide tank mix provided the best field management system for mammoth cultivars under the conditions of this study.
- MH residues on flue-cured tobaccoJones, James L. (Virginia Cooperative Extension Service, 1979-04)MH is a systemic growth regulator which has been used successfully by tobacco producers for nearly 20 years. Recently there has been concern over rising levels of MH residue on U.S. tobacco.
- Nitrification inhibition by metalaxyl as influenced by pH, temperature, and moisture content in three soilsMoore, J. Michael (Virginia Polytechnic Institute and State University, 1989)Metalaxyl, [N—(2,6-Dimethylphenyl)-N-(Methoxyacetyl)-alanine methyl ester], is used extensively in tobacco (Nicotiana tabacum L.) production for prevention of black shank (Phytophthora parasitica Dast. var. nicotianae), blue mold (Peronospora tabacina Adam), and damping-off (Pythigm spp.). Metalaxyl is also patented as a nitrification inhibitor, although not marketed for that purpose. Proper maturity and ripening of flue-cured tobacco depends on an adequate supply of N through the time of removal of the inflorescence, with a declining supply of N from that point. Use of a chemical which might prolong the availability of N in tobacco could delay maturity and reduce the quality of the cured leaf. These studies were conducted to determine whether metalaxyl might inhibit nitrification under a broad range of soil physical and environmental conditions prevalent in the tobacco producing areas of Virginia. The influence of soil type, soil pH, soil temperature, and soil moisture on inhibition of nitrification by metalaxyl (1 mg kg⁻¹) were investigated in three soils used extensively for tobacco production. Soils used in the study were Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludult), Appomattox fine sandy loam (clayey, mixed, thermic Typic Kandhapludult), and Mattoponi sandy loam (clayey, mixed, thermic Typic Hapludult). Metalaxyl did not inhibit nitrification under any of the conditions studied. However, NO₂⁻ accumulation with metalaxyl was sometimes greater than the control, especially at high pH (7.0) in the Cecil and Appomattox soils, and at 10 and 20°C. Nitrite and NO₃⁻ accumulations from four rates of metalaxyl (1, 5, 25, and 125 mg kg⁻¹) were compared with those of an untreated control and a nitrapyrin standard over a seven week soil incubation period in further studies using the same soils and adjusted pH levels. Significant NO₂⁻ accumulation occurred during the first week after treatment at high pH in all soil types, with 5, 25, and 125 mg kg⁻¹ metalaxyl. Only the 125 mg kg⁻¹ metalaxyl treatment caused NO₂⁻ accumulation at the high pH in all soils beyond the second week after treatment, with the peak occurring in most cases between weeks three and four. Nitrate accumulation proceeded normally in all soil types and pH levels except with treatments of 25 and 125 mg kg". Nitrate accumulations with 25 mg kg⁻¹ were similar to those for nitrapyrin. The 125 mg kg⁻¹ rate was consistent in causing near total inhibition of NO₃⁻ accumulation at all pH levels in all soils. Nitrate accumulation tended to be lower at lower soil pH levels compared to the highest pH for all soils. Little difference in nitrification due to soil appears to be evident. Use of metalaxyl at recommended rates of 0.25 to 1.5 mg kg⁻¹ would not be expected to inhibit nitrification.
- Strip-Tillage Production Systems for TobaccoJerrell, Scottie Lee (Virginia Tech, 2001-05-14)Conservation tillage production systems for flue-cured tobacco (Nicotiana tabacum L.) have been studied for many years. Inadequate chemical weed control and lack of acceptable pesticide and fertilizer application resulted in consistently lower yields and inferior cured leaf quality. The development of new conservation tillage equipment, improved methods of fertilizer application, and new herbicides, have resulted in a renewed interest in conservation tillage labeled for tobacco. This research investigated management practices to address slow early season growth characteristic of strip-tillage tobacco production. Objectives of the first study were to evaluate the methods of starter fertilizer application and determine the optimal rate. A transplant water treatment (11 kg ha⁻¹) and 3 rates (11, 22, and 45 kg ha⁻¹) of injected 9-45-15 (N:P₂O₅:K₂O) water soluble starter fertilizer were evaluated for early season plant growth and time of topping. Starter fertilizer treatments increased tobacco root weight by 22% and leaf area up to 41%. Earlier topping was observed as a result of starter fertilizer with 23 and 6% more plants topped during the initial topping date in 1999 and 2000, respectively. Starter fertilizer did not consistently increase the yield of either strip-tillage or conventional tillage tobacco. The objectives of the second study were to compare the use of raised beds with flat-planting and investigate cover crop residue management techniques. Residue management treatments minimized residue within the strip-tilled area with an early hooded spray application (strip-killed) of a burndown herbicide as opposed to the traditional broadcast burndown application. The use of raised beds for strip-tillage production of tobacco showed no clear benefit when compared to flat-planting. Strip-tillage plots were similar to conventional tillage for cured leaf quality and yield. Early season strip-kill burndown herbicide applications proved beneficial in reducing difficulties incorporating residue into the strip-tilled area thus improving the quality of the prepared seed bed. This research has added to the present knowledge regarding strip-tillage tobacco production, and refined necessary cultural practices. Transplant starter fertilizer is recommended to overcome the typical slow early season growth characteristic of strip-tilled tobacco. However, increased rates (greater than 11 kg ha⁻¹) or under-row injection of the material had no added benefit. The research also demonstrated that the use of raised beds should not be considered a necessary practice with the use of a strip-till implement that incorporates under-row subsoil tillage. This research has demonstrated that tobacco yields and quality comparable to conventional tillage can be realized using strip-tillage production techniques.
- Summary of agronomic on-farm test demonstrations in flue-cured tobaccoJones, James L. (Virginia Cooperative Extension Service, 1981-02)This publication is a summary of agronomic on-farm tests conducted in flue-cured tobacco in 1979 and 1980.
- Virginia dark-fired tobacco - variety information for 1977Jones, James L.; Terrill, T. R. (Virginia Cooperative Extension Service, 1976-10)Presents information that may be helpful in choosing the best varieties of dark-fired tobacco to meet specific production goals.
- Virginia dark-fired tobacco : quality is the keyJones, James L. (Virginia Cooperative Extension Service, 1981-05)Outlines production practices that will help supply the quality tobacco that will be acceptable to the trade.