Dark Tobacco Update

1. Dark Tobacco Update 2008 TN Tobacco Agent Training, February 19, 2008 Andy Bailey Extension Tobacco Specialist Univ. of KY / Univ. of TN

2. Agent Training TopicsDark Tobacco • 2008 crop outlook for dark tobaccos • Nitrogen fertilization • Sucker control • Production differences for dark tobacco • Plant populations and topping • Harvesting / housing / curing • Double-crop curing

3. Dark Tobacco in Kentucky and Tennessee • Approx. 1,500 growers • $78 million in revenue for KY • $44 million in revenue for TN • Some production in • non-traditional areas in 2008. • 30 counties: 20 KY, 10 TN • Approx. 17,950 acres (up 12% from 2006) • 4 Types: • Type 22 Eastern Dark-Fired • Type 23 Western Dark-Fired • Type 35 One-sucker dark air-cured • Type 36 Green River dark air-cured KY T36 Princeton T35 T23 T22 Murray Springfield TN

4. 2007 Dark Tobacco Production Estimate • KY/TN Dark Fired: • 37.6 million lbs (down 5% from 2006) • 13,300 acres (up 12% from 2006) • 2826 lbs/A (down 15% from 2006) • KY/TN Dark Air-Cured: • 12.3 million lbs (down 7% from 2006) • 4,650 acres (up 8% from 2006) • 2644 lbs/A (down 14% from 2006)

5. 2008 Crop Outlook • Dark tobacco acreage increase at least another 12-15% in 2008. • Huge demand and marketing opportunities • 2008 production estimate: • 45 to 47 million pound dark fire-cured crop • 18 to 20 million pound dark air-cured crop • Burley tobacco acreage decrease • Major decrease in dark tobacco areas • Steady or slight decrease in other areas

6. Nitrogen Rate Experiment Christian Co. - Crofton, KY

7. Dark Tobacco Nitrogen Rate Trials 10 trials over 4 locations and 4 yearsVarieties: NL Madole, DF 911, KY 171, KT D4LC Total Yield (lbs/A) Total N Rate (lbs N/A)

8. Possible Effects of Excessive Nitrogen • Increased amounts of green tobacco following curing • Delayed maturity from excessive N in plant at season’s end • Swelled or “fat” stems • Nitrate loading of leaf midrib causing decreased moisture loss • Possible negative effects on cured leaf chemistry 150 300 500 1000

9. Effect of N Rate on Quality and RevenueDark Air-Cured KY 171: HRES, Springfield, TN - 2003 *Revenue values based on federal support price of grades • Revenue reduced by 51% by using 1000 lbs N compared to 150 lbs N

10. KT D4LCBruce Cline Farm – Christian Co. - 2005 • Very upright growth habit • Very high yield potential (4200+ lbs/A) • Good black shank resistance, no black root rot res. • Plant regulation on sticks critical • Stick spacing in barn critical (at least 12”) • Rough leaf texture • Differences in coloring, ordering

11. PD 7302LC New hybrid for 2008 from Rickard Seed Good race 0 black shank resistance, no race 1 resistance Resistant to black root rot and TMV Yield and quality somewhat similar to NL Madole PD 7302LC

12. PD 7309LC New hybrid for 2008 from Rickard Seed Good race 0 black shank resistance, no race 1 resistance No other resistance Yield and quality somewhat similar to NL Madole PD 7309LC

13. Production Differences for Dark TobaccoPlant Populations • Plant population: around 5,000 plants/A (+/- 250) • 40” row spacing, 30” plant spacing • 5227 plants/A • More leaf body in lower stalk positions • Heavier and more solid lugs, better seconds • Fewer plants to cut, spike, pick up, house, take down, strip • Less barn space required • 871 sticks/A (6 plants/stick) • 1,045 sticks/A (5 plants/stick)

14. Madole VA 359 Dark Tobacco Planting Dimensions • Most common: 38 to 42” row spacing, 30 to 32” plant spacing • More upright varieties may respond differently to plant spacing (VA 359, KT D4, KT D8) • i.e. ‘Narrowleaf Madole’ vs. ‘VA 359’ • 39” row spacing; 24”, 28”, 32”, or 36” plant spacing.

15. At higher plant populations, yield/A , yield/plant Dark Tobacco Hill Spacing StudyHopkins Co. – Norris Slaton Farm - 2003 Effect of variety (averaged over plant spacings) Effect of plant spacing (averaged over variety) (0.61) (0.64) (0.71) (0.73) Yield (lbs)/Acre (lbs/plant) 3979 3575 3480 3189 3273 3839 Variety Plant Spacing

16. Topping: Dark Tobacco: Topping stage: Bud stage to 50% bloom Topping height: At least 16 leaves May be most efficient to make 2 toppings Dark TobaccoTopping and Sucker Control

17. Comparison of Bloom Stages and Topping Heights for Dark Tobacco2006 – Chris Rodgers Farm – Graves Co., KY • Variety: Narrowleaf Madole LC, set June 1 • Fire-cured • Bloom Stage at topping comparisons: • Elongated bud • 50% Bloom • 100% Bloom • Topping Height comparisons: • 12 leaves • 16 leaves

18. LSD0.05 = 142 156 270 320 418 (total) Total Yield (lbs/A): 4023 4253 3818 4214 3732 4184 Yield (lbs/A) Bloom Stage – Topping Height NL Madole Comparison of Bloom Stages and Topping Heights for Dark Tobacco2006 – Chris Rodgers Farm – Graves Co., KY

19. Total Yield (lbs/A) LSD0.05 = 296 *Data averaged over topping heights. Main Effect of Bloom Stage on Yield2006 – Chris Rodgers Farm – Graves Co., KY

20. Total Yield (lbs/A) LSD0.05 = 242 *Data averaged over bloom stages. Main Effect of Topping Height on Yield2006 – Chris Rodgers Farm – Graves Co., KY

21. Kerry Wiggins Farm, Graves Co., 2004 Topping Style Comparisons • Eastern district topping style: early topping, 12-leaves • Western district topping style: later topping, 16-leaves

22. Influence of Bloom Stage and Topping Height on Dark Tobacco YieldKerry Wiggins Farm – Sedalia, KY - 2004 100% Bloom, 12 leaves 100% Bloom, 16 leaves

23. Benefits to Harvesting Mature Tobacco

24. When To Harvest Dark Tobacco? • Does not show obvious signs of maturity • Maturity signs: • Leaves show a faint yellow cast • Faint yellow spots, then over entire leaf • Upper leaves thick/oily • Crack readily when folded • Minimum of 5 weeks after topping for most varieties

25. Immature

26. Overmature

27. Early Maturity and Physiological Leaf Breakdown • Plants appear to ripen/mature early • 2 to 3 weeks in some cases • Appears to be precipitated by: • Warmer than normal temperatures in August • Intense sunlight

28. 7 4 5 6 8 9 Holdability and Harvest Timingof Dark Tobacco Narrowleaf Madole Little Crittenden PD 7312LC PD 7302LC PD 7309LC DT 538LC TR Madole KT D8LC KT D4LC KT D6LC TN D950 Burley KY 171 VA 309 VA 359 DF 911 Weeks After Topping

29. Harvest Timing after ToppingNarrowleaf Madole, dark air-cured *Average 2005 dark air-cured price of $2.15/lb.

30. Total Yield (lbs/A): 3114 3060 3434 3509 3606 Total Yield (lbs/A) Harvest Timing (Weeks After Topping) Effect of Harvest Timing on Dark Tobacco2006 - HRREC, Springfield, TNNarrowleaf Madole LC, dark air-cured

31. Fire Curing

32. Top vents End doors Dark Air-Cured Bottom vents Burley Curing • Sticks placed 9 to 12” apart

33. Dark Tobacco Stick Spacing 9-12” stick spacing for dark, 6” for burley • Older dark barns • 3 to 3.5 ft. vertical tier spacing: 18” spacing • Decreased risk of “sweat” or houseburn • Sweat = increased TSNA • Loss of cured leaf weight • Lower quality

34. Comparison of Dark-Fired Tobacco Variety, Nitrogen Rate, and Housing Density2007 – UKREC, Princeton, KY • Varieties: Narrowleaf Madole LC or KT D4LC • N fertility: 200, 300, or 400 total lbs N/A • Housing density: 6” or 12” stick spacing

35. Effect of Variety, N Rate, and Housing Density on Dark-Fired Yield2007 – UKREC, Princeton, KY Total Yield (lbs/A): 3030 3269 3184 3140 3124 3192 3107 Dark-Fired Yield (lbs/A) Total LSD0.05 = 221 270 221

36. Effect of Variety, N Rate, and Housing Density on Dark-Fired Grade Index and Gross Revenue2007 – UKREC, Princeton, KY Quality Grade Index (0-100): 55.5 38.3 50.1 45.3 45.3 42.2 51.6 * * Dark-Fired Gross Revenue ($/A) Rev LSD0.05 = 786 963 786

37. Effect of Variety, N Rate, and Housing Density on Dark-Fired Yield and Quality2007 – UKREC, Princeton, KY • KT D4 will yield at least 300 lbs/A more than NL Mad. • KT D4 has lower quality than NL Madole • KT D4 is more prone to sweat and quality will further decrease when spaced too tightly in barn. • Quality may also decrease at excessive N rates.

38. Fire-Curing • Curing stages for dark fire-cured tobacco: • Yellowing 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 100F, RH 85 to 90%.

39. 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.

40. Double Crop Curing • Increased stick spacing requirements on some contracts limits barn space • Curing 2 crops of dark fired tobacco in the same barn and season • Major savings in barn capacity

41. Double Cropping • Time management: • Set 1st crop early May, second crop mid-June • Yield loss of 300-500 lbs likely on 2nd crop • Try to cure 1st crop in 5 weeks • Aggressive curing

42. Must manage 2 crops separately • when double cropping • Variety selection (maturity characteristics) • Management practices • Weather

43. 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 *See new UK / UT Extension publication: AGR-196

44. Black Shank • Even with newer varieties, we still need to: • Practice good crop rotation • At least 2 years of grass between tobacco crops • Continue to use fungicides • Ridomil or Ultra Flourish • Preplant or layby or both • Use good equipment sanitation • Don’t wait until black shank spreads to start cleaning equipment • 10% bleach solution

45. 2006 Black Shank Fungicide Experiment

46. ApplicationsBlack Shank Fungicide Trial - Christian Co. 2006 • PPI applications made June 21 prior to setting on June 22 • Broadcast (BC) applied at 15 gal/A • 1st cultivation (July 10) and Layby (July 28) applications • Directed 15” band on each side of rows, 15 gal/A • Basal applications made August 2 • 2 oz spray solution applied around base of each living plant • Approx. 81 gal/A if applied to all plants • Black shank already very severe at the time of Layby and Basal applications • Tobacco stand counts taken but trial not harvested due to black shank

47. First Stand Count – July 10 – 2.5 wks after PPI and setting

48. Second Stand Count – August 2 - 6 wks after PPI and setting

49. Effect of Ridomil on Dark Tobacco YieldIn Absence of Black Shank2007 Dark Tobacco Rotational Trial, HRREC, Springfield, TN Total Fire-Cured Yield (lbs/A) KT D6 LC 1 pt/A Ridomil NL Madole LC 1 pt/A Ridomil NL Madole LC No Ridomil KT D6 LC No Ridomil 1st year tobacco

50. Effect of Ridomil on Dark Tobacco YieldIn Absence of Black Shank – NL Madole LC2007 Ridomil/Quadris Trial, MSU, Murray, KY Total Yield (lbs/A): 3567 3580 3779 3576 3673 Fire-Cured Yield (lbs/A) 1 pt Ridomil 1 pt Quadris 1 pt Ridomil 2 pt Quadris 1 pt Ridomil 3 pt Ridomil 2 pt Ridomil