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