Tobacco Production Update

Bob Pearce, Gary Palmer, Andy Bailey Extension Tobacco Specialists

Kenny SeeboldExtension Plant Pathologist

Topics

• Nitrogen sources for tobacco

• Revised nitrogen rates for tobacco

• Sucker control options– No MH options

• Variety update

• Disease update

Nitrogen Fertilizer Issues • Economics

– Leaf prices down– N fertilizer prices up

• Price tied to natural gas• Transportation costs up

• Nitrosamine concerns– Tobacco companies want less N applied

• Quality concerns– Too little: thin body, poor yield– Too much: delayed maturity, fat stems

Ammonium Nitrate Issues• Most common N source for tobacco growers• Homeland security concerns

– Can be used to make explosives– Easy availability

• Some manufacturing plants have closed– Tighter supplies– Higher costs

• Sales regulations– Permits needed to purchase large quantity?– Some dealers reluctant to stock?

Price Per Unit of Nitrogen for Selected Fertilizer Materials

0.000

0.100

0.200

0.300

0.400

0.500

0.600

Year

Pric

e (

$/l

b N

)

Anhydrous Ammonia Ammonium Nitrate Urea UAN Solutions Ammonium Sufate

Alternative N Sources• Anhydrous ammonia (82% N)

– Lowest cost per unit of N– Limited availability– Special equipment needed

• Stored as liquid under pressure• Special injectors needed• Used in illegal meth production

– Feasible only if equipment already available– Placement concerns

• Delayed uptake• Phyto-toxicity if close to plants

Alternative N Sources• Anhydrous ammonia (82% N)

– Reaction in soil• NH3 + 2O2 → H+ + NO3

- +H2O• Same lime requirement as AN

– Suggestions for use• Inject 6 to 8 inches deep• 7 to 10 days before setting

Alternative N Sources• Ammonium sulfate (21% N)

– Specialty fertilizer• Use on acid loving crops

• Use on high pH soils

– Relatively high cost per unit N– Limited availability– Soil reaction

• (NH4)2SO4 + 4O2 → 4H+ +2NO3-+ SO4

2- + 2H2O

• 3X lime requirement of AN

– Not feasible for large scale use on tobacco

Alternative N Sources• Urea (46% N)

– Intermediate cost– Handling similar to ammonium nitrate

• Can impregnate some chemicals

• Same lime requirement as AN

– Converted to nitrate in the soil• Subject to loss if surface applied

– Apply to dry soil

– Incorporate or water in

• Delayed uptake (Don’t use for sidedress)

– Feasible alternative if managed properly

Alternative N Sources• Non Pressure Solutions (28 – 32% N)

– Intermediate cost– Mixture of urea, ammonium nitrate, and water– Relatively easy to transport, store, and apply

• Most nurse tanks• Many types of sprayers

– Corrosive to equipment– Should be incorporated

– Can be used a a carrier for spray applications– Limited availability– Feasible for tobacco production

Alternative N Sources• Calcium – Ammonium Nitrate (27% N)

– Ammonium nitrate mixed with lime• 78% ammonium nitrate

– Theoretically similar to ammonium nitrate• Can impregnate some chemicals ?

– Relatively high cost?– Availability? – Limited practical experience

Alternative N Sources• Sodium Nitrate (16% N)

• Calcium Nitrate (15.5% N)

• Sodium-Potassium Nitrate (15% N)– Immediate uptake (good for sidedress)– Good for low pH soils– Erratic availability – High cost– Low analysis – high transport cost

Conversion to Nitrate in soil

% of Fertilizer as NO3-N

N Source Weeks After Application

0 3 6

Ammonium Nitrate 50 80 90

Anhydrous Ammonia 0 20 65

Urea 0 50 75

UAN Solution 25 60 80

Nitrate Sources 100 100 100

Effects of Ammonium Nitrate Application on Soil pH

5

5.2

5.4

5.6

5.8

6

6.2

6.4

1-M

ay

8-M

ay

15

-Ma

y

22

-Ma

y

29

-Ma

y

5-J

un

12

-Ju

n

19

-Ju

n

26

-Ju

n

3-J

ul

10

-Ju

l

17

-Ju

l

24

-Ju

l

31

-Ju

l

7-A

ug

14

-Au

g

21

-Au

g

Soil pH0 N 240 lbs N

Anhydrous Ammonia, Urea, UAN solutions : similar

Effect of Liming an Acid Soil Prior to Use of Urea and Sodium Nitrate Sources of Nitrogen

5.3

5.8

6.3

4.7

5.7

6

4

4.5

5

5.5

6

6.5

7

0 5 7.5

Tons of Lime/A

So

il p

H

Sodium Nitrate Urea

Both N sources applied at 225 lb N/A pre-plant. Soil pH (water) measured at midseason of each year. Soil pH before liming was 5.4.

Effect of Liming an Acid Soil Prior to Use of Urea and Sodium Nitrate Sources of Nitrogen

2612

2765 2772

2358

26472750

2000

2200

2400

2600

2800

3000

0 5 7.5Tons of Lime/A

Yie

ld l

b/a

Sodium Nitrate Urea

Both N sources applied at 225 lb N/A pre-plant.

Nitrogen Source StudyHarrison Co. – Keith Smith Farm

425 478 438 480

1040 928 1030 1039

1058 1169 1086 1007

323 313 323 342

87

187

148

68

2867287828892846 178

0

500

1000

1500

2000

2500

3000

AN U CN SN LSD

Yie

ld l

b/a

Flyings Lugs Leaf Tips Total

100 units AN Broadcast Sidedressed with 170 units each, AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate

Conventional Fertility TrialMonroe Co. – Al Pedigo Farm

502 532 469 498 544

829976

850 888 850

515

662657 540 544

135

241

110

1939192621691847 1977 400

0

500

1000

1500

2000

2500

450 AN +300 AN

750 AN + -

450 AN +645 CN

450 AN +625 SN

450 AN +217 U

LSD

Yie

ld l

b/a

Flyings Lugs Leaf TotalNumber = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate, U= Urea

Broadcast

Sidedress

No-till Fertility TrialMonroe Co. – Al Pedigo Farm

587 750 674 577 638

10821113 1164

1062 1062

735705 817

710 725

102

181

119

24252348265425672404 295

0

500

1000

1500

2000

2500

3000

450 AN +300 AN

750 AN + -

450 AN +645 CN

450 AN +625 SN

450 AN +217 U

LSD

Yie

ld l

b/a

Flyings Lugs Leaf TotalNumber = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate, U= Urea

Broadcast

Sidedress

Effects of Sidedressing Different Sources of Nitrogen on Burley Yield

Elliot Co. – Tracy D. Kitchen Farm

757 686 790 750

991815

905 873

482

442436 486

2108213019422229

0

500

1000

1500

2000

2500

300 Am Nitrate 222 Urea 645 Ca Nitrate 625 Na Nitrate

Yie

ld l

b/a

Flyings Lugs Leaf

450 Ammonium Nitrate Broadcast followed by 100 lb/a of Nitrogen Sidedressed.Am = Ammonium, Ca = Calcium & Na = Sodium. There were no significant differences.

Effect of Nitrogen Source on Burley YieldMarshall Co. – Glen Thompson Farm

373 381 377 397

1092 1048 970 1084

1176 1303 1203

57

223

1114 310

0

500

1000

1500

2000

2500

3000

Am Nitrate Urea Ca Nitrate Na Nitrate LSD

Yie

ld lb

/a

FLYINGS LUGS LEAF

2579 2605 2650 2684 225

150 units Urea Broadcast Sidedressed with 100 units each at sidedressing, Ca = Calcium and Na = Sodium

Revised Nitrogen Rates

• AGR-1 will have a new table for N on tobacco– Based on crop history (same as old)– No additional N for continuous tobacco– Soil drainage formally considered – “Typical” recommendation 50 lbs. N/A less– Rate lower if sidedressing is practiced

• Economically sound recommendations

• Reduce incidence of over-application

Revised Nitrogen Recommendations for Burley and Dark Tobacco.

Well DrainedSoil

Moderately Well Drained Soil

------------Lb N/A------------

Low N levels: following tobacco or row crops

225-250 250-275

Medium N levels: first-year tobacco following a grass or grass-legume sod

200-225 225-250

High N levels: first-year tobacco following legume sod or legume cover crop

150-175 175-200

Effects of Nitrogen Rates on Burley Tobacco at Spindletop Farm (Maury Silt Loam)

2000

2500

3000

3500

4000

0 50 100 150 200 250 300 350 400

N rate (lb/a)

Yie

ld l

b/a

1991 1992

– MacKown, Sutton and Crafts-Brander – 1994

Nrate across location years and method

y = -0.0061x2 + 4.0053x + 2180.2

R2 = 0.1249

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 50 100 150 200 250 300 350 400

N rate (lbs./A)

Le

af

Yie

ld (

lbs

. A

)

Effect of N rate and method of application on burley tobacco yield.

2000

2250

2500

2750

3000

0 50 100 150 200 250 300 350 400

N rate (lbs/A)

Yie

ld (

lbs/

A)

Poly. (Preplant) Poly. (Split )

If 1/3 or more is sidedressed reduce total amount of N by 15 to 25 lbs./A

Summary

• Encourage growers to compare costs and consider alternative N sources

• Revised N rates – Rates lowered by about 50 lbs./A– Will not significantly lower yield– Improved quality– Promotes desired chemical properties

• Reduce rate if sidedressing is practiced