2020 Virtual Tobacco Field Day
Welcome to the 2020 NC State University Virtual Tobacco Field Day! Thank you for viewing our research updates. Below are YouTube links to 15 video presentations from the tobacco faculty, staff, and graduate students in the College of Agriculture and Life Sciences. You may view individual recordings or select the “Welcome and Introduction” to begin the playlist.
If you would like to ask questions about a specific topic, please submit them to Dr. Matthew Vann (firstname.lastname@example.org). Questions will be compiled and addressed during the Question and Answer segment of the live webinar on July 16.
List of Video Presentations
Dr. Matthew Vann – Department of Crop and Soil Sciences
Dr. Grant Ellington – Department of Biological and Agricultural Engineering
Multiple on-farm locations are utilized to evaluate the potential energy savings and decreased curing time associated with adding a turning vane in a bulk barn lower air plenum. Total energy consumption, static pressure, cure duration, spatial temperature profiles, and other relevant performance information are monitored on all barns compared at a given location. Uniformity in the cured leaf quality or issues with completely drying the tobacco in each box is an ongoing problem for some growers. One of the locations selected has observed poorer cured leaf quality in specific boxes compared with the rest of the barn. Installing a turning vane may improve airflow uniformity through all the boxes and decrease the labor associated with the cured leaf market preparation. Although this technology may not work on all barns, this is a low cost strategy that any grower can implement with minimal assistance.
Yara Rosado Rivera and Dr. Lindsey Thiessen – Department of Entomology and Plant Pathology
Managing black shank (Phytophthora nicotianae) with fungicides alone may not provide the highest level of control and favors fungicide resistance development. Varieties with low, moderate, and high resistance to black shank were evaluated in combination with three fungicide programs. Integrate programs with both host resistance and fungicides reduced disease at high disease pressure sites.
Raymond Garcia Rodriguez and Dr. Lindsey Thiessen – Department of Entomology and Plant Pathology
Biological controls in combination with low and moderate host resistance were evaluated over two years in high disease pressure environments. Several biological control and variety combinations reduced disease. In places where fumigation is not an option, incorporating biologicals may be beneficial to limit Granville wilt impacts.
Dr. Lindsey Thiessen and Yara Rosado Rivera – Department of Entomology and Plant Pathology
Recently, an invasive root knot nematode, Meloidogyne enterolobii, has been found in several states in the Southeast US, and is impacting tobacco and its rotational crops. Several commercial chemical management strategies were evaluated over three years in tobacco fields affected by Meloidogyne enterolobii. Fumigant treatments containing 1,3-dichloropropene (Telone II) were most consistent at reducing losses to this nematode.
Cordelia Machanoff and Dr. David Suchoff – Department of Crop and Soil Sciences
Both sessions will highlight the work of MS student Cordelia Machanoff. Her research focused on developing conservation tillage practices through the use of a rolled cereal rye cover crop and a no-till transplanter. Additionally, the use of different colored plastic mulches with drip irrigation was investigated for its efficacy in managing weeds and effects on yield and leaf quality.
Dr. Alex Woodley – Department of Crop and Soil Sciences
The production of organic flue-cured tobacco requires costly nitrogen (N) management strategies, intensive tillage and bedding, and repeated cultivation for bed maintenance and weed control. This study was conducted to determine if cover cropping could mitigate the significant economic investment of N fertilization in organic tobacco. In 2018 and 2019, the effects of three winter cover crops: hairy vetch (Vicia villosa Roth); Austrian winter pea (Pisum sativum var. arvense L.); and crimson clover (Trifolium incarnatum L.), were compared to typical N management without a cover crop, and investigated for their potential to supplement N to a flue-cured tobacco crop in North Carolina. Tobacco yields were significantly greater under cover crop treatments in both years. Crop value was significantly greater in legume cover crop treatments in 2019, and did not differ from the control in 2018. In 2019, in-season soil samples showed cover-crop N was removed from the system at topping, a critical marker of a necessary N-free period for the maturation of the leaves. Only hairy vetch at the Kinston location showed elevated nitrogen at topping compared to the control, however this did not have a negative effect on quality, yield, or value. Cover crops are not traditionally used in tobacco production due to concerns with unpredictability of nitrogen supply and extended N mineralization compromising the quality of the cured tobacco leaf. Our research did not support these concerns, and found evidence supporting the potential use of cover-crop N as a cost-effective management strategy in the production of flue-cured tobacco.
Dr. Matthew Vann – Department of Crop and Soil Sciences
Pesticide residues found on cured tobacco remain a large concern to the allied tobacco industry. To better quantify cured leaf residues, three active ingredients (fluopicolide, indoxacarb, and oxathiapiprolin) were applied to flue-cured tobacco grown in six North Carolina environments from 2016 to 2018. Fluopicolide residues were consistently among the highest documented in this evaluation (7.25 ppm maximum), which was most likely a result of the compound having the shortest PHI (7 days) among the products tested. The highest indoxacarb residue was 2.15 ppm, which was identified in lower-stalk position samples collected from one environment in 2018. Additional data suggests that indoxacarb residues are likely to be <2.0 ppm. Oxathiapiprolin was below the limit of quantification (0.09 ppm) in 98.6% of the samples analyzed and averaged 0.10 ppm in the lower-stalk position of one environment in 2017. In 2019, investigations were initiated to quantify residues of cyantraniliprole, flutriafol, flutriafol + azoxystrobin, and S-metolachlor.
Dr. Matthew Vann – Department of Crop and Soil Sciences
At present, seven different herbicide active ingredients are labeled for US tobacco production. Two of these (sulfentrazone and clomazone) are applied to ≈70% of the acreage in North Carolina. With the threat of herbicide resistance, commercial farmers need additional active ingredients. Research was conducted from 2016 through 2018 in order to best identify application patterns of rimsulfuron and S-metolachlor that might prove beneficial in tobacco systems. Results will be discussed in the recorded presentation.
Maggie Short and Dr. Matthew Vann – Department of Crop and Soil Sciences
Previous fertilizer research in flue-cured tobacco has compared a wide range of nutrient programs, ultimately demonstrating the usability and function of numerous sources. The objective of this study was to investigate the influence of nitrogen (N) based sources to the assimilation of other macro and secondary nutrients. Basal treatments consisted of granular 6-6-18 or liquid 28-0-0 urea-ammonium nitrate (UAN) and potassium sulfate (0-0-50). Sidedress N sources were ammonium nitrate potassium (ANK), ammonium nitrate sulfate (ANS), or UAN. Each basal and sidedress source was paired to create a two x three factorial treatment arrangement. Four weeks after transplanting, the analysis of foliar tissue samples revealed higher concentrations of phosphorus and potassium in treatments containing 6-6-18 (0.36 and 3.36%, respectively) relative to UAN and potassium sulfate (0.29 and 3.04%, respectively). Foliar concentrations of macro and secondary nutrients were similar at flowering, with the exception of sulfur, which was lowest in the UAN + UAN treatment. After curing, foliar potassium was greatest in treatments containing 6-6-18 + ANK (2.12%) relative to 6-6-18 + UAN (1.78%), UAN + UAN (1.80%), and UAN + ANK (1.57%). Despite differences in foliar nutrient concentrations, cured leaf yield, quality, price, and value per acre were similar, meaning that each these fertility programs is likely suitable for use in tobacco production. This point is further reinforced by the fact that nutrient concentration was deemed sufficient within each sampling interval, regardless of treatment. With the knowledge that practical differences are unlikely to be documented across the programs we evaluated, commercial farmers are encouraged to consider fertilizer price rather than performance when selecting nutrient sources.
Collin Blalock and Dr. Matthew Vann – Department of Crop and Soil Sciences
With a current global over-supply of flue-cured tobacco, tobacco producers in North Carolina have been encouraged to remove the lowermost leaves prior to harvest due to their low value in manufactured products. In field trials, the removal of 4 or 8 leaves per plant at topping reduced cured leaf yield by 575 and 805 lbs/a, respectively, when compared to systems absent of leaf removal (2,654 lbs/a). While cured leaf quality was not affected by leaf removal programs, per hectare value declined by 19 to 24% within the same treatments. Despite the negative impacts to yield and value, the four leaf removal program did not impact crop throw. However, the eight leaf removal program completely eliminated lug grades while increasing the portion of leaf and tip grades. Machine-harvest production budgets indicate that net economic return was reduced from approximately $US 1,119/a in programs absent of lower leaf removal to $US 397 and 272/a in 4 and 8 leaf removal programs, respectively. In hand-harvest programs, net return was reduced even further, with treatments absent of leaf removal being more profitable than the 4 and 8 leaf removal programs ($US 817, 121, and 32/a, respectively). Ultimately, cost savings are found in leaf removal programs; however, they are not large enough to offset the profitability reductions generated from significant yield losses.
Dr. Ramsey Lewis – Department of Crop and Soil Sciences
Dr. Ramsey Lewis of the Crop and Soil Science is responsible for the tobacco breeding and genetics research program at NC State University. In his presentation, he will discuss a newly released flue-cured tobacco hybrid, several that are being considered for future commercialization, and efforts to improve overall soil borne disease resistance in tobacco while maintaining yielding ability.
Dr. Bill Foote – North Carolina Crop Improvement Association
The Recorded Variety Trial is a replicated planting of representative seed samples from of all tobacco varieties offered for sale in NC. It is a cooperative effort by North Carolina Crop Improvement Association, N.C. Department of Agriculture and Consumer Services and NC State Tobacco Extension to verify that varieties offered for sale in North Carolina are true-to-type, match the phenotypic description, and will perform predictably. It is also the final step of tobacco seed certification for varieties sold as a class of certified seed
Dr. Hannah Burrack – Department of Entomology and Plant Pathology
Dr. Burrack will address new research topics coming from her research program and provide an insect mangement update for 2020. Research discussions include:
1.) Assessing efficacy of new materials on tobacco flea beetle, thrips, and tobacco budworm
2.) Deterimining application timing and frequency for tobacco budworm infecting baculoviruses
3.) TSWV observations from 2020
9 a.m. – Welcome: Dr. Matthew Vann – Extension Agronomist, Dept. of Crop and Soil Sciences
9:05 a.m. – NC State University Programs Update: Dr. Rich Bonanno – Associate Dean, CALS and Director, NC State Extension
9:15 a.m. – NC State Extension Update: Dr. Dale Monks, Associate Director, NC State Extension and ANR Program Leader
9:25 a.m. – North Carolina Agricultural Research Programs Update: Dr. Steve Lommel, Associate Dean for Research CALS, Director NCARS and Dr. Loren Fisher, Assistant Director NCARS
9:35 a.m. – Tobacco Situation and Outlook: Dr. Blake Brown, Hugh C. Kiger Professor, Dept. of Agricultural and Resource Economics
9:55 a.m. – 2020 Tobacco Season Overview: Disease, Insect, and Agronomic Issues – Dr. Lindsey Thiessen, Extension Plant Pathologist, Dept. of Entomology and Plant Pathology; Dr. Hannah Burrack, Extension Entomologist, Dept. of Entomology and Plant Pathology; Dr. Matthew Vann, Extension Agronomist, Dept. of Crop and Soil Sciences
10:15 a.m. – Question and Answer Segment
10:30 a.m. – Conclude Webinar