Dark Tobacco Update - Tobacco Info Online

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

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Dark Tobacco Topics
2008-2009 crop outlook
Dark Variety update
Curing

Total KY/TN Dark Tobacco
2008 Crop Projection
County Agent Survey
Dark Type Total Production (million lbs)
Dark Fired 57.68 million lbs
Dark Air‐Cured 21.14 million lbs
Total Dark Crop
(Fired and Air‐Cured)
78.82 million lbs
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
Variety Maturity Black Shank Use*
Race 0 Race 1
Yield
Score
Quality
Score
Black Root
Rot
Fusarium TMV Wildfire
NL Mad LC Med-Late None None F/A 7 9 None None None None
TR Madole Medium None None F 6 9 None None None None
Lit Crit Med-Late None None A/F 5 9 None None None None
DF 911 Medium None None F 8 6 High None High High
KY 160 Medium None None A 3 9 None None High None
KY 171 Medium None None A/F 7 7 High Med High None
VA 309 Early-Med Med Low A/F 6 8 Low - None -
VA 359 Medium Low Low A/F 6 8 Low - None -
TN D950 Early Med Med F 8 5 High None High High
KT D4 LC Medium Med Med F/A 9 5 None - None None
DT 538 LC Medium Med Med F/A 8 7 - - - -
KT D6 LC Medium Med Med F 8 7 High None High High
PD 7312 LC Medium None None F/A 7 8 High Med High None
PD 7302LC Medium High None F/A 6 7 High - High -
PD 7309LC Medium High None F/A 7 8 None - None -
KT D8LC Medium Med Med F/A 9 6 None - None None
PD 7318LC Medium High None F/A 8 8 High - High -
*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.

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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

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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
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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

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Sister line to KT D4LC
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KT D8LC
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.

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PD 7302LC
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 7302LC
Danny Miller Farm, 2008

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PD 7309LC
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 7309LC
Danny Miller Farm, 2008

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PD 7318LC
Rickard, 2009
Similar to NL Mad
Good quality
Good yield
potential
Race 0 BS
resistant
No Race 1 BS
resistance
Black root rot
resistant
PD 7318LC
Danny Miller Farm, 2008

Yield (lbs/A)
4000
3500
3000
2500
2000
1500
1000
500
2008 Dark Air-Cured Variety Trial
0
NL Mad LC
Yield -
1576 1326 1363 1630 1644
HRREC, Springfield, TN
1467
1211 1515
1459 1572 1688 1900 1327 1656 1744
1394 1444 1435 1247 1152 1637 1243 1273 1523 1467 1302 1073 1461 1279 1307
210 0 204 289 252 305 202 286 187 288 213 300 214 202 232 240
Lit Crit
KY 171
LSD 0.05
VA 309
VA 359
= 67 321 296 249 (total)
Lug Second Leaf
Total Yield/A (lbs):
3181 2973 3087 3129 3101 3306 2739 2974 3270 3252
PD 7312LC
PD 7302LC
PD 7309LC
KT D4LC
KT D6LC
KT D8LC
3290 3187 2991 3167 3292
DT 538LC
DT 595
D2601
D2602

Grade Index (0-100)
2008 Dark Air-Cured Variety Trial
Quality Grade Index - HRREC, Springfield, TN
LSD 0.05
= 11.5

Yield (lbs/A)
2008 Dark Fire-Cured Variety Trial
4500
4000
3500
3000
2500
2000
1500
1000
500
0
NL Mad LC
Yield -
2017 2113 2004 1882
HRREC, Springfield, TN
2211 2728 2343 2577 2716
2346 1942 1975 1963
2751 2252
1074 1032 976 1002 1167 1054 1299 1043 1259 972 1136 966 1023 1083 1461
120 0 109 136 114 112 149 115 132 106 108 129 119 116 115 87
TR Mad
KY 171
LSD 0.05
VA 309
= 39 445 419 372 (total)
Lug Second Leaf
Total Yield/A (lbs):
3211 3254 3116 2997 3490 3931 3757 3752 4081 3426 3207 3060 3102 3948 3799
TN D950
KT D4LC
KT D6LC
KT D8LC
DT 538LC
PD 7312LC
PD 7302LC
PD 7309LC
PD 7318LC
D2404
D2405

Grade Index (0-100)
2008 Dark Fire-Cured Variety Trial
Quality Grade Index - HRREC, Springfield, TN
LSD 0.05
= 14.2

Evaluation of Dark Tobacco Varieties
Christian Co. –
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under Black Shank Pressure
Trial set June 11
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Kent Boyd Farm –
42” rows, 30” plant spacing
4978 plants/A
Predominantly Race 0 black
shank
Plant mortality evaluated
throughout season
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2, 4, 6, 9 wks after setting
Preharvest
Yield data collected using
preharvest stand counts
Fire-cured
– 2 fires over 22 days
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Hopkinsville, KY -
8 varieties tested
Randomized complete
block design with 4
replications
2-row plots, 80 ft. long
Varieties:
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Narrowleaf Madole LC
DT 538LC
KT D4LC
KT D6LC
PD 7302LC
PD 7318LC
D2602 (experimental)
PD 305H (experimental)
2008

Evaluation of Dark Tobacco Varieties
Christian Co. –
Under Black Shank Pressure
Kent Boyd Farm –
Hopkinsville, KY -
Variety Tested Black Shank Resistance
Race 0 Race 1
Narrowleaf Madole LC None None
DT 538LC Medium Medium
KT D4LC Medium Medium
KT D6LC Medium Medium
PD 7302LC High None
PD 7318LC High None
D2602 (experimental) High Medium
PD 305H (experimental) High Medium
2008

Variety
Evaluation of Dark Tobacco Varieties
Under Black Shank Pressure
Christian Co. –
% Stand
2 wks after
setting
Kent Boyd Farm –
% Stand
4 wks after
setting
% Stand
6 wks after
setting
Hopkinsville, KY -
% Stand
9 wks after
setting
% Stand
at harvest
2008
Total Yield
(lbs/A)
NL Mad LC 95.6 94.5 57.4 24.6 18.8 554
DT 538LC 93.8 93.8 92.7 91.9 85.3 2819
KT D4LC 92.7 92.7 92.7 86.4 77.9 2574
KT D6LC 97.1 96.3 94.5 81.3 66.9 2287
PD 7302LC 96.0 96.0 95.6 93.8 89.3 2851
PD 7318LC 94.5 94.5 91.2 85.3 79.8 2415
D2602 94.1 94.1 94.1 93.8 93.4 3293
PD 305H 97.1 97.1 97.1 96.3 95.6 3143
LSD 0.05 4.6 4.3 15.3 23.7 24.7 962

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Evaluation of Dark Tobacco Varieties
under Intensive Black Shank Pressure
Daviess Co. -
Tony and Joe Fischer Farm –
2 quarts/A Ultra Flourish applied
PreTr Inc. to entire trial area.
Trial set June 4
Plant mortality evaluated
throughout the season
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2, 4, 6, 9 weeks after setting
Preharvest
Trial harvested September 9
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Air-cured
Stripped November 13
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Owensboro, KY -
2008
9 varieties tested
Randomized complete block
with 4 replications
2-row plots, 60 ft. long
Varieties:
– Narrowleaf Madole LC
– VA 359
– KT D6
– KT D8
– PD 7302LC
– PD 7309 LC
– PD 7318LC
– PD 305H (experimental)
– D2602 (experimental)

Daviess Co. ‐
Evaluation of Dark Tobacco Varieties
under Intensive Black Shank Pressure
Tony and Joe Fischer Farm –
Owensboro, KY –
Black Shank Resistance Levels of Varieties Tested
Variety Tested Black Shank Resistance
Race 0 Race 1
Narrowleaf Madole LC None None
VA 359 Low Low
KT D6LC Medium Medium
KT D8LC Medium Medium
PD 7302LC High None
PD 7309LC High None
PD 7318LC High None
PD 305H (experimental) High Medium
D2602 (experimental) High Medium
2008

Daviess Co. -
Variety
Evaluation of Dark Tobacco Varieties
under Intensive Black Shank Pressure
% Stand
2 wks after
setting
Tony and Joe Fischer Farm –
% Stand
4 wks after
setting
% Stand
6 wks after
setting
Owensboro, KY –
Stand Counts throughout the season and final yield/A
% Stand
9 wks after
setting
% Stand
at harvest
Total Yield
(lbs/A)
NL Mad LC 93.8 93.3 15.6 3.1 0.40 13
VA 359 97.8 95.5 12.9 4.9 1.8 95
KT D6LC 96.0 96.0 88.4 58.0 39.7 1770
KT D8LC 95.1 95.1 94.6 71.0 46.0 1717
PD 7302LC 94.2 91.1 0.40 0.0 0.0 0
PD 7309LC 98.7 96.9 16.1 5.8 2.2 82
PD 7318LC 94.6 91.1 1.3 0.0 0.0 0
2008
PD 305H 95.5 95.1 87.5 48.2 36.2 1292
D2602 95.1 95.1 92.0 73.2 56.3 2126
LSD 0.05 5.6 5.9 11.6 24.1 22.6 993

NL Madole LC
No black shank resistance
VA 359
Low Race 0, Low Race 1

PD 305H
R0 + R1
PD 7309LC
Race 0 resistance, no race 1
Daviess Co. 2008
D2602
R0+R1

PH-gene Dark Varieties and Race 1
2 months after setting – Owensboro, KY 2008
PD 7302LC PD 7309LC PD 7318LC
Black Shank Variety Trial - Tony and Joe Fischer Farm – Owensboro, KY 2008

Burley
TN D950
Holdability and Harvest Timing
VA 309
VA 359
TR Madole
of Dark Tobacco
KT D6LC
KY 171
KT D4LC
KT D8LC
4 5 6 7 8 9
DT 538LC
PD 7312LC
Weeks After Topping
DF 911
Little Crittenden
PD 7302LC
PD 7309LC
PD 7318LC
Narrowleaf Madole

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Dark Air-Curing
Curing process similar to burley
Requirements for dark air-cured:
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Dark
Air-Cured
Burley
Better air-cured barns (no outdoor structures)
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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

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Air‐Curing Air Curing Tobacco
Harvest mature tobacco, but don’t don t cut late.
Weather dictates air‐curing air curing
Barn management has some effect
Requires slow chemical reactions to change
tobacco from green to uniform brown
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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

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Air‐Curing Problems
Low humidity/high temperature
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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
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Houseburn/sweat, microbial growth and
excessive weight loss

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Manipulating Air‐Curing Conditions
Barn management has most effect on humidity
Low humidity: ▼ ventilation (2007)
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Could add moisture to barn floor to increase humidity
Beware of excessive moisture and mold growth
High humidity: ▲ ventillation
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Dark air‐cured: Could add heat to ▼ humidity, ▲ drying
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Dry heat from wood or coke fires

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Barn Management for Air‐Curing
Housing
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Burley: 6” spacing in barns; 4” in structures
Dark: 9” to 12” in barns
General Practices
No overlap between tiers: shingle or skip tiers
Normally need greatest
ventilation/air movement during
first 3 to 4 weeks after housing
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Exception: dry curing seasons of 2007
and 2008
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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

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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
Air Curing Structures
*Outdoor structures not recommended for dark tobacco

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Low Cost Air‐Curing Structures
Interest in building non‐traditional barns
Advantage: substantial cost savings
Disadvantages:
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Lower capacity?
Leaf quality?
Options:
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Outdoor curing structures –various styles
Tarp barns
Sheds

Tarp Barns

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Tarp Barns
Ends open –lots of ventillation
Life of tarp: 10 to 15 years
Heath Thurby –Henderson Co.
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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

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Curing Sheds
Versatile –house tobacco or store equipment
Excellent ventilation
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24 ft. x 36 ft., closed on ends
3 cantilever beams per shed
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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

Variations on Barn Designs

Removable Tiers

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Fire Curing
Tobacco housed 5-8 5 8 days prior to 1 st firing
Fired 2 to 6 times with hardwood slabs/sawdust
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3-4 4 days to 2 wks/fire
Initial fires (yellowing/colorsetting):
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95 to 110 F
Drying: 120 to 135 F
Finishing 110 to 120 F

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Fire-Curing
Curing stages for dark fire-cured tobacco:
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Yellowing the leaves
Setting leaf color
Drying down stalks and leaves
Applying smoke “finish”
to leaves
Yellowing done with ventilation and no fires
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Open vents and/or use fans for 5 to 8 days
Fires started when yellow spots begin to appear.
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All vents closed except those in the top of the barn.
Hardwood slabs covered with sawdust.
Initial fires increase barn temperature to 95 to 100°F,
RH 85 to 90%.

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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
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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
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Smoke deposits on the leaf add aroma and texture
Sequential low fires with no ventilation to maximize smoke levels
and minimize temperature in barn.

Tobacco
Alkaloids:
TSNAs:
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Tobacco Specific Nitrosamines
(TSNAs)
Nicotine Nornicotine Anatabine Anabasine
4-methyl-Nnitrosamino-1-(3pyridyl)-1butanone
(NNK)
N-nitrosonornicotine
(NNN)
N-nitrosoanatabine
(NAT)
4 major TSNAs: NNN, NNK, NAT, NAB
N-nitrosoanabasine
(NAB)
Formed from nitrosation of tobacco alkaloids nicotine,
nornicotine, anatabine, anabasine during curing
Carcinogenic compounds in tobacco products

PPM Total TSNA
6
5
4
3
2
1
0
Effect of Seed Source and N Fertility on
TSNA Trends During Fire-Curing
UKREC, Princeton, KY - 2006
0.420.560.290.44 0.310.32
0.4 0.42
Housing Prior to 1st
Firing
unscreened NL Mad, 150 N/A unscreened NL Mad, 300 N/A
NL Mad LC, 150 N/A NL Mad LC, 300 N/A
Average
1.5
1.97
0.82
3.58
Prior to 2nd
Firing
1.78
3.15
2.13
5.27
Prior to 3rd
Firing
4.42
4.23
3.94
3.3
Prior to 4th
Firing
3.96
3.16
4.02
3.78
After 4th
Firing
2.76
3.75
2.75
3.32
Takedown
Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7
Day 1 Day 6 Day 11 Day 24 Day 40 Day 56 Day 63

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Double-Crop Curing
Curing 2 crops of tobacco in 1 barn
Advantages:
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Major cost savings for barns
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Fewer needed
Easier to keep labor force
occupied
Barns can be consolidated
closer to tobacco
Companies receiving earlier
to accommodate early crop
stripping
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Disadvantages:
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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

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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

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Time management:
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Set 1 st
Try to cure 1 st
Double Cropping
crop early May, second crop mid-June
Aggressive curing
crop in 5 weeks

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2 Crops
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5 weeks between transplanting dates
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1 st
crop set early May, 2 nd
crop set mid-June mid June
2 crops managed separately throughout season
Neither crop set at ideal time
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Double Crop Curing
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:
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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
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Stripped at takedown or 3 to 4 weeks later

PPM TSNA
6
5
4
3
2
1
0
2005 Double Crop Curing Experiment
Takedown and Stripping Samples
Highland Rim Research & Education Center, Springfield, TN
Takedown Samples Stripping Samples (First Cure)
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3.42
*
Misted
*
4.72
*
Steamed
First Cure
4.07
1.42
Misted
1.66
Steamed
Second Cure
1.54
3.19
Scaffolded
5.14
Bulked
5.38
Scaffolded
3.9
Bulked
Misted Steamed
3.84
Early Stripped
5.44
Late Stripped
3.95
Early Stripped
5.1
Late Stripped
Scaffolded Bulked

PPM TSNA
6
5
4
3
2
1
0
2006 Double Crop Curing Experiment
Takedown, Stripping, and Delivery Samples
Highland Rim Research & Education Center, Springfield, TN
Takedown
Samples
2.07
3.84
Misted
Steamed
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*
First
Cure
2.96
*
2.45
Misted
1.76
Steamed
Second
Cure
2.11
2.7
2.98
Scaffolded
Bulked
Stripping Samples
2.322.28
Scaffolded
Bulked
2.2
Early Stripped
2.82
Late Stripped
2.71
2.54
Early Stripped
Late Stripped
Misted Steamed Scaffold Bulked
3.79
4.61
Scaffolded
Bulked
Delivery Samples
2.55
3.78
Scaffolded
Bulked
3.63
Early Stripped
2.7
Late Stripped
5.27
Early Stripped
3.12
Late Stripped
Misted Steamed Scaffold Bulked

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Best Management Practices for
Double-Crop Curing
Conditioning / ordering:
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Overhead misting may be preferred over steaming
Takedown:
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Scaffold wagon may be preferable to bulking
Time of stripping:
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Strip tobacco as soon as possible following takedown
Deliver tobacco as soon as possible following stripping
*See new publication online: AGR-196

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Fire Curing and Sawdust
Sawdust shortages in 2008, will probably continue
Interest in developing contact list of sawmills to help
growers in sourcing.
Charlotte, TN: Wood grinding unit that can grind
wood into sawdust specifically for dark fire-curing. fire curing.
Can reduce sawdust requirements by 50% or more
by using wood chips if available
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Still need sawdust for stem drying

Use of Wood Chips in Fire-Curing
Fires 1 and 2
End of yellowing
Color setting
Slabs/Sawdust
Fire 3
Drying
Slabs/Sawdust
Fire 4
Finishing
Slabs/chips/dust
2008 Princeton, KY
35% Reduction in sawdust usage
Fire 5
Finishing
Slabs/woodchips

Websites:
Dark Tobacco:
http://ces.ca.uky.edu/darktobacco
Dark Tobacco Agent’s site:
http://ces.ca.uky.edu/darktobacco/Agent.htm
Burley Tobacco:
http://www.uky.edu/Ag/Tobacco
Burley Tobacco Agent’s site:
http://www.uky.edu/Ag/Tobacco/Agent.htm