Evaluation of Correlation between Within-Barn Curing Environment and TSNA Accumulation in Dark Air-Cured Tobacco

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Evaluation of Correlation between Within-Barn

Curing Environment and TSNA Accumulation

in Dark Air-Cured Tobacco

Preliminary Study Grant Report

CORESTA TSNA Sub-Group

M.D. Richmond, W.A. Bailey, R.C. Pearce

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Objectives



Evaluate variability in curing conditions

within dark air-cured barns



Attempt to correlate changes in curing conditions

with changes in nitrite and TSNA levels in the cured leaf



Broader impact to growers:



Targeted barn repairs

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Materials and Methods



Dark tobacco varieties:



TR Madole screened (TRsc)



TR Madole High Converter (TRHC)



375 sticks of each needed (2250 plants)



Two Locations:



Princeton (UKREC) and Lexington (Spindletop)



Varieties are grown side by side in the field



Plant population 12,100/ha

3 AP2013 - TSNA Study Grant Report

Centre de Coopération pour les Recherches Scientifiques Relatives au Tabac

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Materials and Methods



Transplants grown at each location



Tobacco transplanted to field in mid-late May



Field Management:



Current UK extension recommendations followed at each site



Field preparation through harvest



N rate: 336 kg N/Ha



Harvest:



Approximately 5 weeks after final topping



Stalk harvested with adequate field wilting

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Materials and Methods



Replicated soil and green leaf samples

taken prior to harvest at each location



6 soil samples (3 per variety) – nitrate analysis



6 green leaf samples:



4th leaf from top, 3 samples per variety

o

Nitrite analysis

o

TSNA analysis

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Housing



3 tiers high and 5 tiers wide



50 sticks on each tier at 23-30 cm stick spacing



Sticks on each tier alternate between TRHC and TRsc



5 sticks of TRHC



5 sticks of TRsc



5 sticks TRHC



5 sticks of TRsc

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HOBO Placement and Sampling



27 HOBO data loggers per barn



Each tier has 5 sets of 10 sticks



(5 TRsc, 5 TRHC)



HOBO placed between

the 5 TRsc and 5 TRHC



In sets 1, 3, and 5

on all tiers of rooms 1, 3, and 5



No HOBO meters in rooms 2 and 4

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Housing and Meter Placement in Barns

R

o

m

1 Tier 3

(top)

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

Tier 2

(middle)

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

Tier 1

(bottom)

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

5 st.

TR sc

5 st.

TR HC

= Placement of HOBO meter (27 meters per barn).

5 rooms/tiers wide and 3 tiers high per barn, HOBO meters and sampling done in rooms 1, 3, and 5.

Cured leaf sampled at end of curing:

•

4 th

_{leaf from top of 20 plants in each 5-stick plot of TRHC and TRsc on each side of each meter}

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AP2013-TSNA Report Centre de Coopération pour les Recherches Scientifiques Relatives au Tabac

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Statistical Analysis

for 2012 Curing Season



SAS version 9.3



Whole plot is Randomized Complete Block Design (RCBD)



Location



Split Plot design



Variety



PROC GLM



General linear model



ANOVA table

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Statistical Analysis 2012

Source

DF

Type I SS

Mean Square

F Value

Pr > F

RH_Count

1 84.3099813

84.3099813

18.36 0.0002

Location

1 14.9275259

14.9275259

3.25 0.0830

HOBO_Placement

26 23.3068465

0.8964172

0.44 0.9787

**Location*HOBO Placement**

24 49.0573558

2.0440565

0.45 0.9750

Variety

1 503.3184943

503.3184943

109.60 <.0001

HOBO Placement Variety

26 27.0442807

1.0401646

0.23 0.9998

R-Square

Coeff Var

Root MSE

TSNA Mean

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7.03 5.91 5.68 8.65 7.21 5.73 7.20 7.18 5.69 6.24 5.93 4.42 7.65 7.31 8.07 8.07 6.81 6.65 8.93 5.42 8.19 7.42 6.36 7.94 6.58 7.32

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

0

100

200

300

400

500

600 L

-1

L

-2

L

-3

L

-4

L

-5

L

-6

L

-7

L

-8

L

-9

L

-1

0 L

-1

1 L

-1

2 L

-1

3 L

-1

4 L

-1

5 L

-1

6 L

-1

7 L

-1

8 L

-1

9 L

-2

1 L

-2

2 L

-2

3 L

-2

4 L

-2

5 L

-2

6 L

-2

7 Lexington Relative Humidity > 80%

and TRHC TSNA Content for Entire Cure

RH HRS ABOVE 80%

TOTAL TSNA

Average number of hours above 80% relative humidity= 407

Average TRHC TSNA content= 6.82 µg/g

Cooperation Centre for Scientific Research Relative to Tobacco 13

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2.51 2.67 2.41 3.24 2.34 2.22 3.1 6.32 2.7 3.76 5.4 5.75 3.62 4.02 2.44 4.41 2.05 3.08 2.98 2.31 2.67 2.4 2.47 _2.35 5.77

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

0

50

100

150

200

250 Princeton Relative Humidity >80%

and TRHC TSNA Content for the Entire Cure

RH HOURS ABOVE 80%

TOTAL TSNA

Average number of hours above 80% relative humidity= 131

Average TSNA content= 3.37 µg/g

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Summary



Significant effect of number of hours above 80% relative

humidity on TSNA



Greater correlation between number of hours above 80%

relative humidity and TSNA at Lexington (407 hrs vs. 131 hrs at

Princeton)



As number of hours above 80% relative humidity increases, the

correlation between relative humidity and TSNA increases



No effect of HOBO placement on TSNA in 2012

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Research Progress



Second Year:



Tobacco crop has been harvested and housed at both locations



Green leaf samples are in storage for freeze drying

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Thanks for the support from:



CORESTA



Altria Client Services



Dr. Andy Bailey and Dr. Bob Pearce



Anne Jack, Colin Fisher,

Neal Fannin, and everyone

involved with TSNA analysis.



Research Technicians

Bobby Hill, Chris Rogers

and Jack Zeleznik



Dr. Wood and Kristen McQuerry

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