Nitrosamines and Plant Nitrosamines and Plant NutritionNutrition

Dr. Gary PalmerDr. Gary Palmer

University of KentuckyUniversity of Kentucky

What are Nitrosamine?What are Nitrosamine?

Nitrogen containing compounds that are Nitrogen containing compounds that are know to have a potential affect on cancerknow to have a potential affect on cancer

Those occurring in tobacco are specific to Those occurring in tobacco are specific to tobaccotobacco TSNA (TSNA (TTobacco obacco SSpecific pecific NNitrositrosAAminesmines))

Occur during curingOccur during curing Increase during storage of cured leafIncrease during storage of cured leaf

Major Factors that Influence Major Factors that Influence TSNA AccumulationTSNA Accumulation

Curing ConditionsCuring Conditions Related to rate of curing and moisture contentRelated to rate of curing and moisture content

StorageStorage Related to moisture content and nitrogenous Related to moisture content and nitrogenous

compoundscompounds Nitrogen FertilizationNitrogen Fertilization

Rate?Rate? Source?Source?

Varietal DifferencesVarietal Differences NornicotineNornicotine

Nornicotine can Nornicotine can

Effect of 250 lb/a Nitrogen Fertilizer on Effect of 250 lb/a Nitrogen Fertilizer on Nicotine, Nitrate, Nitrite and TSNA Nicotine, Nitrate, Nitrite and TSNA

Accumulation in Air-Cured Tobacco LaminaAccumulation in Air-Cured Tobacco Lamina

Fertilizer

treatment

nicotine NO3-N NO2-N TSNA

% ppm ppm ppm

0 (control) 1.75 1710 3.5 2.49

transplant 1.99 5985 3.4 6.40

midseason 2.04 4265 2.7 6.68

topping 1.84 2945 3.2 5.40

Nitrogen Source StudyNitrogen Source StudyHarrison Co. – Keith Smith FarmHarrison Co. – Keith Smith Farm

425 478 438 480

1040 928 1030 1039

1058 1169 1086 1007

323 313 323 342

87

187

148

68

2846 2889 2878 2867 178

0

500

1000

1500

2000

2500

3000

AN U CN SN LSD

Yie

ld l

b/a

Flyings Lugs Leaf Tips Total

112 kg/ha AN Broadcast Sidedressed with 168 kg/ha each, AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate

Nitrate & Nitrite levels Nitrate & Nitrite levels

from different N sourcesfrom different N sources Harrison Co. – Keith Smith FarmHarrison Co. – Keith Smith Farm

0

4

8

12

16

20

pp

m(p

pb

)

AN 4.82 0.41 H 403 18.72 0.29

U 4.91 0.39 18.55 0.3

CN 4.58 0.49 16.5 0.24

SN 4.7 0.4 17.68 0.3

LSD 0.64 0.15 2.81 0.15

Nitrate (Nitrite) Variety Nitrate (Nitrite)

112 kg/ha AN Broadcast Sidedressed with 168 kg/ha each, AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate

Lamina Mid-rib

Nitrosamine levels Nitrosamine levels

from different N sourcesfrom different N sources Harrison Co. – Keith Smith FarmHarrison Co. – Keith Smith Farm

0

0.2

0.4

0.6

0.8

1

1.2

pp

m

AN 0.29 0.627 H 403 0.841 1.14

U 0.307 0.616 0.395 0.647

CN 0.286 0.59 0.304 0.495

SN 0.27 0.553 0.354 0.621

LSD 0.094 0.153 0.808 0.948

NNN Total Variety NNN Total

112 kg/ha AN Broadcast Sidedressed with 168 kg/ha each, AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate

Lamina Mid-rib

Fertility TrialFertility TrialJackson Co. – Mike Huff FarmJackson Co. – Mike Huff Farm

401 366 420 429 440

353 381459 503 533

551 555576

625 563

175

330

223

1305 1302 1455 1557 1535 496

0

500

1000

1500

2000

1680 5-10-15 560CN+SN

840AN -

504AN 336AN

504AN 722CN

504AN 700SN

LSD

Yie

ld l

b/a

Flyings Lugs Leaf Total

Number = kg of product/ha, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate

BroadcastSidedress

Nitrosamine levels Nitrosamine levels

from different N sourcesfrom different N sources Jackson Co. – Mike Huff FarmJackson Co. – Mike Huff Farm

02468

101214

pp

m(p

pb

)

1680 5-10-15 506 CN+SN 0.99 0.77 R 630 5.12 0.85

840AN - 1.75 0.74 8.48 0.97

504AN 336AN 2.48 0.85 11.22 0.9

504AN 722CN 2.72 0.92 12.32 1.34

504AN 700SN 2.72 0.72 12.05 1.83

LSD 0.95 0.28 3.68 1.11

Nitrate (Nitrite) Variety Nitrate (Nitrite)

Number = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate

Broadcast Sidedress

Lamina Mid-rib

Nitrosamine levels Nitrosamine levels

from different N sourcesfrom different N sources Jackson Co. – Mike Huff FarmJackson Co. – Mike Huff Farm

0

2

4

6

8

10p

pm

1680 5-10-15 506 CN+SN 1.52 2.18 R 630 1.69 2.1

840AN - 1.75 2.6 1.32 1.72

504AN 336AN 1.77 2.62 2.77 3.33

504AN 722CN 2.56 3.66 3.1 3.66

504AN 700SN 1.57 2.42 1.7 2.2

LSD 0.69 1.06 1.68 1.84

NNN Total Variety NNN Total

Number = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate

Broadcast Sidedress

Lamina Mid-rib

Effects of Nitrogen Rate on Burley Yield

Madison Co. – Gregg Harris Farm

610 579 508 516 516 632

1867 1869 20601697

2017 19842032

672 704 672805

746 776 716

522

267

192

3993147 3151 3240 3019 3279 3282 3381

0

500

1000

1500

2000

2500

3000

3500

504 AN 672 AN 840 AN 1008 AN 1176 AN 1344 AN 504 AN + 800 14-0-14

LSD

Yield kg/ha

Flyings Lugs Tip

All plots received 450 lb/a Ammonium Nitrate Broadcast followed by the remainder of the nitrogen shortly after transplanting. AN = Ammonium Nitrate. 14-0-14 is a calcium/potassium nitrate mix

161

Effects of Nitrogen Rate on Burley Yield

Shelby Co. – Gilbert Ray Tucker, Jr. Farm

322 314 308 304 306 377

632 870563 620 594 552 725

13711396

1591 1573 1729 17891755

352356 370 372

398 422435

384

3291314630272870283229362678

0

500

1000

1500

2000

2500

3000

3500

504 AN 672 AN 840 AN 1008 AN 1176 AN 1344 AN 504 AN + 800 14-0-14

Yield kg/ha

All plots received 450 lb/a Ammonium Nitrate Broadcast followed by the remainder of the nitrogen shortly after transplanting. AN = Ammonium Nitrate, MS=mid-season, LS=late season.

Adding 714 lb/a 14-0-14 significantly improved yield over 450 lb/a alone

Influence of Seed Influence of Seed Source on TSNA Source on TSNA

LevelsLevels

Screening Air-cured Varieties for Nornicotine Conversion

High levels of the nornicotine increases chance for high TSNA levels

A variety may have a high number of converters in a population Conversion is Chemical Change of Nicotine

to Nornicotine By selection of non-converters, a “clean”

line can be established

Ethephon Treatment

Screening (3%)Screening (3%)

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4

nic + nornic %

co

nvers

ion

%

Effect of Screening

Lowers mean conversion • does not necessarily eliminate all

converter plants• most dramatic with high converters• reduced effect with low converters

Effect of screeningEffect of screening

8 2

Unscreened Screened

TN 90

VA 50957 5

Bottom Line Screened seed

• lower nornicotinewill HELP reduce TSNAs – no guaranteeenable growers to meet manufacturers needs

• Need to identify screened seedlotscan only do this by renaming screened

varieties

““LC” Varieties Screened varieties

• Re-released as “LC” varieties “LC” varieties available to growers in 2005TN 90LC, TN 86LC, TN 97LC, KT 200LC, KY

907LC

NO difference except for conversion• Same for yield, quality, disease

resistanceTN 90 “LC” is still TN 90

Accumulation of TSNA during Storage

Accumulation of TSNA during Storage

Air-curing experiments have shown that a substantial nitrite production during air-curing does not necessarily lead to high levels of TSNA in cured tobacco.

pH of the cured tobacco = 6 Not an effective pH for reaction between alkaloids

and nitrite Other Nitrogenous compound may react with

alkaloids even under dry conditions

Avoiding TSNA accumulation during storage of cured tobacco Good curing process with as low nitrite

formation as possible Tobacco in the bales should not be packed

too tightly Allows ventilation of nitrogenous compounds into

atmosphere Instead of reacting with alkaloids

Moisture content in the bales should be as low as possible Prevent any chemical reactions and microbial

growth