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UT Tobacco Agent Training March 6, 2009 Highland Rim Res & Educ Ctr Springfield, TN. Dark Tobacco Update. Andy Bailey Tobacco Extension Specialist Univ. of KY / Univ. of TN Princeton, KY. Dark Tobacco Topics. 2008-2009 crop outlook Dark Variety update Curing.
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UT Tobacco Agent Training March 6, 2009 Highland Rim Res & Educ Ctr Springfield, TN Dark Tobacco Update Andy Bailey Tobacco Extension Specialist Univ. of KY / Univ. of TN Princeton, KY
Dark Tobacco Topics • 2008-2009 crop outlook • Dark Variety update • Curing
Total KY/TN Dark Tobacco2008 Crop ProjectionCounty Agent Survey USDA estimate for total 2008 dark crop = 87.5 million lbs. Probably lost 1.5 million lbs of dark-fired and 0.1 million lbs dark air-cured to Hurricane Ike. *2009 crop down from 2008 -- Reductions in buying intentions from all companies 2009 crop more like 2005 crop (40 to 45 million lbs dark-fired, 12 to 14 million lbs air-cured).
2009 Dark Tobacco Variety Guide *F or A refers to use as fire-cured or air-cured variety. F/A indicates either use, with predominant use given first. Relative yield and quality scores given on a 0-10 scale, with 10 being best for the predominant use. Dash (-) means that resistance level is unknown or not rated at present.
KT D6 LC • First hybrid dark tobacco released from KY-TN breeding program • KT D4LC x TN D950 • Leaf texture more like TN D950 • Maturity should be later than TN D950? • Available for growers in 2007 • Black shank and black root rot resistance • Improved curing and leaf quality over KT D4LC • Yield potential slightly less than KT D4LC
DT 538 LC • Released from Newton Seed in 2006 • Black shank resistance similar to KT D4 • Maturity similar to KT D4 • Yield potential slightly less than KT D4 • Excellent leaf quality • Cured leaf quality superior to KT D4 • Lugs tend to fade in color • May fire up from bottom more • Some curing problems in 2008? • Restrictions against DT 538 by some buyers for 2009
Sister line to KT D4LC Same genetics, disease resistance, and high yield potential as KT D4 Different seed selection Medium Race 0 and Race 1 black shank resistance No black root rot, TMV, or wildfire resistance Medium maturity Same potential quality problems as KT D4 Restrictions by some buyers against KT D4 and KT D8 in 2009. KT D8LC
PD 7302LC PD 7302LC Danny Miller Farm, 2008 Rickard, 2008 Similar to KY 171 Good quality Good yield potential Race 0 BS resistant No Race 1 BS resistance Black root rot resistant
PD 7309LC PD 7309LC Danny Miller Farm, 2008 Rickard, 2008 Similar to NL Mad Good quality Good yield potential Race 0 BS resistant No Race 1 BS resistance No Black root rot resistance
PD 7318LC PD 7318LC Danny Miller Farm, 2008 Rickard, 2009 Similar to NL Mad Good quality Good yield potential Race 0 BS resistant No Race 1 BS resistance Black root rot resistant
2008 Dark Air-Cured Variety TrialYield - HRREC, Springfield, TN LSD0.05 = 67 321 296 249 (total) Total Yield/A (lbs): 3181 2973 3087 3129 3101 3306 2739 2974 3270 3252 3290 3187 2991 3167 3292 Yield (lbs/A)
2008 Dark Air-Cured Variety TrialQuality Grade Index - HRREC, Springfield, TN LSD0.05 = 11.5 Grade Index (0-100)
2008 Dark Fire-Cured Variety TrialYield - HRREC, Springfield, TN LSD0.05 = 39 445 419 372 (total) Total Yield/A (lbs): 3211 3254 3116 2997 3490 3931 3757 3752 4081 3426 3207 3060 3102 3948 3799 Yield (lbs/A)
2008 Dark Fire-Cured Variety TrialQuality Grade Index - HRREC, Springfield, TN LSD0.05 = 14.2 Grade Index (0-100)
Evaluation of Dark Tobacco Varieties under Black Shank PressureChristian Co. – Kent Boyd Farm – Hopkinsville, KY - 2008 • Trial set June 11 • 42” rows, 30” plant spacing • 4978 plants/A • Predominantly Race 0 black shank • Plant mortality evaluated throughout season • 2, 4, 6, 9 wks after setting • Preharvest • Yield data collected using preharvest stand counts • Fire-cured • 2 fires over 22 days • 8 varieties tested • Randomized complete block design with 4 replications • 2-row plots, 80 ft. long • Varieties: • NarrowleafMadole LC • DT 538LC • KT D4LC • KT D6LC • PD 7302LC • PD 7318LC • D2602 (experimental) • PD 305H (experimental)
Evaluation of Dark Tobacco Varieties Under Black Shank Pressure Christian Co. – Kent Boyd Farm – Hopkinsville, KY - 2008
Evaluation of Dark Tobacco Varieties Under Black Shank Pressure Christian Co. – Kent Boyd Farm – Hopkinsville, KY - 2008
Evaluation of Dark Tobacco Varieties under Intensive Black Shank PressureDaviess Co. - Tony and Joe Fischer Farm – Owensboro, KY - 2008 • 2 quarts/A Ultra Flourish applied PreTr Inc. to entire trial area. • Trial set June 4 • Plant mortality evaluated throughout the season • 2, 4, 6, 9 weeks after setting • Preharvest • Trial harvested September 9 • Air-cured • Stripped November 13 • 9 varieties tested • Randomized complete block with 4 replications • 2-row plots, 60 ft. long • Varieties: • NarrowleafMadole LC • VA 359 • KT D6 • KT D8 • PD 7302LC • PD 7309 LC • PD 7318LC • PD 305H (experimental) • D2602 (experimental)
Evaluation of Dark Tobacco Varieties under Intensive Black Shank PressureDaviess Co. - Tony and Joe Fischer Farm – Owensboro, KY – 2008 Black Shank Resistance Levels of Varieties Tested
Evaluation of Dark Tobacco Varieties under Intensive Black Shank PressureDaviess Co. - Tony and Joe Fischer Farm – Owensboro, KY – 2008Stand Counts throughout the season and final yield/A
NL Madole LC No black shank resistance VA 359 Low Race 0, Low Race 1
PD 305H R0 + R1 D2602 R0+R1 PD 7309LC Race 0 resistance, no race 1 Daviess Co. 2008
PH-gene Dark Varieties and Race 12 months after setting – Owensboro, KY 2008 PD 7309LC PD 7318LC PD 7302LC Black Shank Variety Trial - Tony and Joe Fischer Farm – Owensboro, KY 2008
7 4 5 6 8 9 Holdability and Harvest Timingof Dark Tobacco Narrowleaf Madole Little Crittenden PD 7312LC PD 7302LC PD 7309LC PD 7318LC DT 538LC TR Madole KT D8LC KT D4LC KT D6LC TN D950 Burley KY 171 VA 309 VA 359 DF 911 Weeks After Topping
Dark Air-Cured Burley Dark Air-Curing • Curing process similar to burley • Requirements for dark air-cured: • Better air-cured barns (no outdoor structures) • Not as open as some burley barns • Wider stick spacing (12”) • Open firing? (heat and no smoke) – may not be needed • Dark more prone to sweat/houseburn and mold • Control with stick spacing and ventillation
Air-Curing Tobacco • Harvest mature tobacco, but don’t cut late. • Weather dictates air-curing • Barn management has some effect • Requires slow chemical reactions to change tobacco from green to uniform brown • Slower for dark than for burley • Optimum conditions • 65 to 90 F (mean daily) • 65 to 70% RH (mean daily) • 15 ft/min air velocity
Air-Curing Problems • Low humidity/high temperature • Drying, not a cure • Low humidity/satisfactory temperature • Variegated, piebald or green tobacco • Low or high humidity/low temperature • Green tobacco • High humidity/high temperature • Houseburn/sweat, microbial growth and excessive weight loss
Manipulating Air-Curing Conditions • Barn management has most effect on humidity • Low humidity: ▼ ventilation (2007) • Could add moisture to barn floor to increase humidity • Beware of excessive moisture and mold growth • High humidity: ▲ ventillation • Dark air-cured: Could add heat to ▼ humidity, ▲ drying • Dry heat from wood or coke fires
Barn Management for Air-CuringGeneral Practices • Housing • Burley: 6” spacing in barns; 4” in structures • Dark: 9” to 12” in barns • No overlap between tiers: shingle or skip tiers • Normally need greatest ventilation/air movement during first 3 to 4 weeks after housing • Exception: dry curing seasons of 2007 and 2008 • Low temperature (≤60 F) and/or low humidity early in cure = • Casty green dark tobacco, light/high-colored burley • Barn doors/vent open except during inclement weather • Less ventilation needed once color is set in lamina
Air Curing Structures • Barns • Inefficient use of labor • Inconsistent conditions • Long term storage • Stick spacing and airflow management critical • Other structures • Facilitate air movement • Cycle in/out of order • Curing not storage • Risk of weather damage • Manage covers more than barn vents and remove when cured *Outdoor structures not recommended for dark tobacco
Low Cost Air-Curing Structures • Interest in building non-traditional barns • Advantage: substantial cost savings • Disadvantages: • Lower capacity? • Leaf quality? • Options: • Outdoor curing structures – various styles • Tarp barns • Sheds
Tarp Barns • Ends open – lots of ventillation • Life of tarp: 10 to 15 years • Heath Thurby – Henderson Co. • 40 ft. x 120 ft. • 2 tiers high – scaffolding, wood or pipe • 5,000 sticks (5-6 acres dark) • Cost: $18,500 for metal and tarp $6,000 lumber for tiers $25,000 ($35,000+ for conv. barn)
Curing Sheds • Versatile – house tobacco or store equipment • Excellent ventilation • 24 ft. x 36 ft., closed on ends • 3 cantilever beams per shed • Limited housing space (1 tier) • Sticks can blow out on ends, need some protection (trees) • Dark: 80 sticks per beam (40 sticks/side), 240 sticks/shed • Burley: 120 sticks per beam (60 sticks/side), 360 sticks/shed • 3 sheds: house 1 acre of tobacco • Cost: less than $1,000 per shed
Tobacco housed 5-8 days prior to 1st firing Fired 2 to 6 times with hardwood slabs/sawdust 3-4 days to 2 wks/fire Initial fires (yellowing/colorsetting): 95 to 110 F Drying: 120 to 135 F Finishing 110 to 120 F Fire Curing
Fire-Curing • Curing stages for dark fire-cured tobacco: • Yellowing the leaves • Setting leaf color • Drying down stalks and leaves • Applying smoke “finish” to leaves • Yellowing done with ventilation and no fires • Open vents and/or use fans for 5 to 8 days • Fires started when yellow spots begin to appear. • All vents closed except those in the top of the barn. • Hardwood slabs covered with sawdust. • Initial fires increase barn temperature to 95 to 100F, RH 85 to 90%.
Fire-Curing • Color set when leaf midrib is still green but leaf lamina is uniform brown color. • 6 to 8 hrs to several days • Leaf drying • Increase ventilation (all vents open) • Heat increased to approx. 135, RH decreased to 75 to 80% • Lamina will crack when touched, bottom half of midrib brown (7 to 14 days). • Tobacco allowed to absorb moisture and then firing repeated until uniform color is achieved • Applying finish • Smoke deposits on the leaf add aroma and texture • Sequential low fires with no ventilation to maximize smoke levels and minimize temperature in barn.
4 major TSNAs: NNN, NNK, NAT, NAB Formed from nitrosation of tobacco alkaloids nicotine, nornicotine, anatabine, anabasine during curing Carcinogenic compounds in tobacco products Tobacco Specific Nitrosamines(TSNAs)
Effect of Seed Source and N Fertility on TSNA Trends During Fire-CuringUKREC, Princeton, KY - 2006 PPM Total TSNA
Advantages: Major cost savings for barns Fewer needed Easier to keep labor force occupied Barns can be consolidated closer to tobacco Companies receiving earlier to accommodate early crop stripping Disadvantages: More management required Tighter window of opportunity Operations must be timely All barns will not work Curing conditions may not be ideal, particularly 2nd crop. Steamers or misting systems must be available for takedown Still need 2 barns worth of sticks Where to store 1st crop during second curing Double-Crop CuringCuring 2 crops of tobacco in 1 barn
Double Crop Curing • Curing 2 crops of dark fired tobacco in the same barn and season • Increased stick spacing requirements on some contracts limits barn space • Major savings in barn capacity
Double Cropping • Time management: • Set 1st crop early May, second crop mid-June • Try to cure 1st crop in 5 weeks • Aggressive curing
Double Crop Curing • 2 Crops • 5 weeks between transplanting dates • 1st crop set early May, 2nd crop set mid-June • 2 crops managed separately throughout season • Neither crop set at ideal time • 200 to 300 lb/A yield reduction compared to single crop set at optimum date
Must manage 2 crops separately • when double cropping • Variety selection (maturity characteristics) • Management practices • Weather
Double Crop Curing Experiment HRREC, Springfield, TN: 2005-2006 Objective: • Discover Best Management Practices for curing and managing two crops of dark-fired tobacco in the same barn and crop year. Treatment comparisons: • Conditioning method • Steaming or misting • Takedown method • Scaffold wagon or bulk • Time of stripping for 1st cure • Stripped at takedown or 3 to 4 weeks later
2005 Double Crop Curing ExperimentTakedown and Stripping SamplesHighland Rim Research & Education Center, Springfield, TN Stripping Samples (First Cure) Takedown Samples PPM TSNA Late Stripped Scaffolded Bulked Late Stripped Steamed Early Stripped Early Stripped Bulked Misted Scaffolded Steamed Misted First Cure 4.07 Second Cure 1.54 Misted Scaffolded Steamed Bulked * * * *
2006 Double Crop Curing ExperimentTakedown, Stripping, and Delivery SamplesHighland Rim Research & Education Center, Springfield, TN Takedown Samples Stripping Samples Delivery Samples PPM TSNA Steamed Bulked Scaffolded Bulked Late Stripped Early Stripped Bulked Early Stripped Scaffolded Late Stripped Late Stripped Late Stripped Bulked Misted Early Stripped Scaffolded Scaffolded Early Stripped Misted Steamed First Cure 2.96 Second Cure 2.11 Steamed Scaffold Bulked Misted Misted Steamed Scaffold Bulked * * *