topping. question 1 why do plants have leaves? as a store for seed production

Topping

Question 1

Why do plants have leaves? As a store for seed production

Historical Perspective

Late topping/ full Late topping/ full bloombloom Past DemandPast Demand

Lighter bodied Lighter bodied style of tobaccostyle of tobacco

Milder tasteMilder taste Non-filteredNon-filtered

Sucker controlSucker control Hand removalHand removal No chemical No chemical

controlcontrol

Physiological Aspect of Topping

Leaf Spread Removal of non-beneficial nutrient sink Root stimulation

Timing Best when 10-25% of

plants have one flower open Effects on plant

Darker cured leaf color

Prior to physiological maturity Prior to stalk hardening

Increases root development More leaf expansion in lower

part of plant

Yield TrendsYield Trends Bud Topping

Yield loss in most varieties Good for late maturing varieties

10-25% Best for most varieties Good quality

50-75% Suckers initiated in some varieties

100%+ Yield decline Sucker initiation in all varieties Opportunistic diseases Senescence

Disease Incidence Hollow Stalk

Late Top Harden Stalk Ragged Top

Effects of Topping Time on Yield

504 553 570 579

1666 1755 1729 1657

625 631 594 604

2958 2876 28402795

0

500

1000

1500

2000

2500

3000

Bud 10-25% 50-75% 100%

Bloom Stage

Yie

ld l

b/a

12 trials over 10 years

Topping Height Root system

Supports a finite leaf yield Leaf number

20 leaves Larger leaves Highest Yield sometimes

26 leaves Smaller leaves Slightly higher Yield most times

Effects of Topping Time on Yield

608 612 586 598 625 630

1374 1442 1368 1421 1451 1390

686 701 710 703 686 676

269727632722266427552668

0

500

1000

1500

2000

2500

3000

20 26 - Bud 10-25% 50-75% 100%

Leaf Number Bloom Stage

Yie

ld l

b/a

17 trials over 9 years

Effects of Topping Time on Leaf Yield

8.286.58 7.32 7.45 7.57 7.38

0

2

4

6

8

10

20 26 - Bud 10-25% 50-75% 100%

Leaf Number Bloom Stage

Yie

ld g

/leaf

17 trials over 9 years

Topping Study Labor ComparisonsLawrence Co. – Malcom Smith Farm

465 432

703 678

495 577

784 778

2447 2465

0

500

1000

1500

2000

2500

20 26

Leaf Number

Yie

ld l

b/a

Topping Study Labor ComparisonsLawrence Co. – Malcom Smith Farm

19.3333.83

154.67

203.00

21.1336.40

169.07

218.39

0

50

100

150

200

250

Cut hr/a Strip hr/a Cut Cost/a Strip Cost/a

20

26

Topping Study Returns ComparisonsLawrence Co. – Malcom Smith Farm

$3,744.00 $3,771.00

3000

3500

4000

Gross returns/a

$/a

20

26

Based on $1.53 average price

On a Larger Scale

6 leaves per plant 42,000 per acre

Based on 7000 population 420,000

Based on 10 acres 1,035,000

Based on 24 acres

Mechanical Topping

Sucker Control

Systemic Maleic Hydrazide

Form Potassium Salt

Brands Royal MH 30 Super Sucker Stuff Fair Plus Etc.

Systemic Maleic Hydrazide

Activity Systemic Control of whole plant Control Cell Division

Application 1.5 to 2 gal/a regular concentrate 1 to 1.5 gal/a high concentrate Avoid heat of the day Nozzles

Fine – Hollow Cone Course – Solid Cone

Advantages

Lasts for 3 to 4 weeks Ease of application Systemic

Basipetal movement Reaches ground suckers

Major Disadvantage Residues in cured tobacco

Standard Industry

80 ppm Maximum

European 60 ppm Maximum

Over application due to lack of confidence in the product

Disadvantages (Cont’d)

Breakdown of control Poor application methods

Too little volume Coverage

Poor weather conditions Leaf not receptive under dry

conditions

Disadvantages (Cont’d)

Artificial maturity Bronzing Tip burn

Stops cell division Retards leaf

expansion on small leaves

Not rain safe Reapply full rate if rain

within 6 hrs Reapply ½ rate if rain

occurs within 6 to 12 hrs

MH Injury Residual MH left in sprayers from previous years

can injure young plants

Contacts

Fatty alcohols Brands

Royal-Tac Fair 85 Sucker Plucker Off-Shoot T

Activity Contact Control Kills actively growing tissue

Application

Coarse spray (Full cone 3 nozzles arrangement)

Rate (4-6% solution) Avoid temperatures in excess of 90 oF

Advantages

No residue No bronzing Does not stop cell division Rain safe after 2 hrs

Disadvantages

Short residual control Reapplication required If chemical misses sucker, no control (not

systemic) Leaf Drop under high temperatures

Local Systemic Dinitroanaline

(DNA) Prime+, Butralin & FluPro

Activity Stops cell division

Application Coarse spray (Full cone 3 nozzles arrangement)

Drop lines

Rate (2% solution in 50 gal/a) Run Down

Jug method

Equipment Hand

Jug method Backpack

High Clearance Sprayer Drop Lines

Advantages

Low residue Extended Control 5-7 weeks Stops cell expansion only in small

suckers Slightly darker top grade when cured

Disadvantages Residual activity of chemical on

cover crops Difficult to apply correctly with

high clearance sprayer Escapes Liberation of dormant ground

suckers

Combination

MH & Prime+ or Butralin Activity

Dual approach Systemic and Local systemic

Controls Cell division

Why Coarse Nozzles? Provide large droplet size

Like rain Runs down stalk

Contacts all leaf axils Where suckers are

Suckers more receptive than Leaf During dry weather

Leaf cuticle more waxy

Fine Nozzles Nozzles

Coverage on upper third of plant Covers mostly leaf During drought

Dries on contact Does not come in contact with sucker bud

Application

Coarse nozzles TG-5 / CE-5 or

equivalent at 4-4.5 mph

TG-3 / CE-3 or equivalent at 2.5-3 mph

Effects of Application of MH by Coarse vs Fine Nozzles on Yield of

Burley Tobacco

0

500

1000

1500

2000

2500

3000

3500

4000

Yie

ld lb

/a

Fine 2398 3105 1713 2352 2074 2697 2194 2911 2355

Coarse 2617 3474 1998 2498 2291 2949 2397 3014 2524

Bath Fleming Jackon Knox LaurelLawrenc

eNelson

Pendleton

Average*

Rate

1.5 gal/a MH (regular concentrate)+ .5 gal/a of Prime+ or Butralin

1 gal high concentrate +.5 gal/a of Prime+ or Butralin

Influence of Sucker Control Across Four Location on Burley Tobacco Yield

2380 2507 2557 2411 2578 2546

0

500

1000

1500

2000

2500

3000

Yie

ld lb

/a

Locations = Bath, Knox, Jackson & Pendleton LSD 0.05 = 177

Average MH Residues by State1997-2004

0

20

40

60

80

100

120

KY IN MO NC OH TN VA Other ALL

ppm MH

Limited sample numbers on all but KY and TN 2000 & 2004 values are from warehouse sales only

Distribution of MH Residue of MH Residue Across All States 2000 & 2004Across All States 2000 & 2004

0

30

60

90

120

ppm MH

Frequency

2000 (169) 2001 (275) 2002 (252) 2003(241) 2004(184)

2000 (169) 28 62 50 20 7 2

2001 (275) 87 105 62 10 5 5 1

2002 (252) 92 79 50 21 5 1 1 2 1

2003(241) 76 95 53 12 3 2

2004(184) 61 75 27 9 7 1 2 2

0 1-40 41-8081-120

121-160

161-200

201-240

241-280

281-320

MH MH Residue Frequency Data for Frequency Data for Kentucky 2000 & 2004Kentucky 2000 & 2004

01020304050607080

ppm MH

Frequency

2000 (116) 2001 (169) 2002(149) 2003(145) 2004(109)

2000 (116) 16 41 38 15 5 1

2001 (169) 37 70 45 8 5 3 1

2002(149) 49 47 33 13 3 1 0 2 1

2003(145) 32 62 38 10 2 1

2004(109) 28 49 17 7 5 0 2 1

0Jan-40

41-8081-120

121-160

161-200

201-240

241-280

>280

Range of MH Residues in Kentucky for 1997 - 2004

0102030405060708090

100

%

Extremely High 2.11 8.73 5.45 0 0.59 2.01 0 2.75

Very High 14.21 9.82 14.55 5.17 4.73 2.68 2.07 4.59

High 20.53 13.82 21.09 12.93 4.73 8.72 6.9 6.42

Medium 29.47 29.82 25.45 32.76 26.63 22.15 26.21 15.6

Low 33.68 37.82 33.45 49.14 63.31 64.43 63.45 70.64

1997 1998 1999 2000 2001 2002 2003 2004

Low < 41, Medium = 41-80, High = 81-120, Very High = 120 - 200, Extremely High >200 ppm

Advantages of Combination of Combination Higher yields Better returns Improved sucker control Lower MH residue Extended Control 5-7 wks Rain safety after 2 hrs Produces darker cured leaf Not as weather dependent No cover crop concern No ground sucker concern Improved grower confidence

Disadvantage

Higher Cost

Controlling Late Season

Insects

Aphid OptionsAphid OptionsInsecticide Rate/Acre Harvest Interval

Small PlantsSmall Plants Large PlantsLarge Plants (days)

Acephate, Bracket, Orthene 2/3 lb 1 lb 3

Orthene 97 3/4 lb 3/4 lb 3

Fulfill 50 WDG 2.75 oz 2.75 oz 14

Golden Leaf Tobacco Spray 2/3 qt 1 - 1/3 qt 5*

Phaser 3E 2/3 qt 1 - 1/3 qt 5*

Pravado 1.6 F 2 to 4 fl oz 2 to 4 fl oz 14

Thiodan (Endosulfan) 2/3 qt 1 - 1/3 qt 5*

Lannate 90 SP 1/2 lb 1/2 lb 14

*Application of products containing endosulfan within 28 days of harvest can lead to increased residue on the crop. Do not spray in the heat of the day

Hornworm OptionsInsecticide Rate/Acre

Harvest Interval

(days)

Acephate (Orthene 75, Bracket) 1 lb 3

Orthene 97 1/2 lb 3

BT products (Agree, Biobit, Dipel, Javelin, Lepinox, Xentari)

0

Denim 0.16 EC 8 to 12 fl. oz. 14

Endosulfan (Golden Leaf Tobacco Spray, Thiodan, Phaser)

2/3 to 1-1/3 qt 5*

Lannate SP 1/2 lb 14

Sevin 80S 2-1/2 lbs 0

Warrior 1.92 – 3.84 fl oz 40

Tracer 4SC 1.4 to 2.9 fl oz* 3

*Application of products containing endosulfan within 28 days of harvest can lead to increased residue on the crop. Do not spray in the heat of the day