York Featuring Managing StemphyliumLeaf Blight Onion ......1/25/2016 1 New York Update: Featuring...

1/25/2016

1

New York Update: Featuring Managing Stemphylium Leaf Blight in Onion with Fungicides

Christy Hoepting

Cornell Cooperative Extension Vegetable Program

Cornell Cooperative ExtensionVegetable Program

Empire Expo, Syracuse, NY: January 20, 2016

Funding for this project was provided by:• Bayer Crop Protection• BASF• DuPont• Syngenta Grower Cooperator:• Chuck Barie & Emma Long, CY Farms, Elba, NY

CVP Program Assistants:• Elizabeth Buck & Missy Call

Stemphylium Leaf Blight in New York

Stemphylium Leaf Blight in New YorkAcknowledgements

Tan and black lesions

Stemphylium Leaf Blight in New YorkStemphylium Leaf Blight in New YorkIntroduction: Stemphylium Leaf

Blight in New York• Caused by Stemphylium vesicarium

Stemphylium Leaf Blight in New YorkStemphylium Leaf Blight in New York

onion “dying standing up”

Introduction: Stemphylium Leaf Blight in New York


Blight in New York• SLB is a secondary invader of downy mildew which ultimately becomes a very aggressive leaf defoliator


Blight in New YorkSevere downy mildew‐ Stemphylium leaf blight epidemic, 2015

1/25/2016

2



Effect of Premature Mortality (Dying Standing Up) on Bulb Rot

2015 experiment



Effect of Premature Mortality (Dying Standing Up) on Bulb Rot

8.2

18.8

5.1

1

15

5.1

16.1

27

11

4

32.4

5.9

0

5

10

15

20

25

30

35

40

direct seeded yellow(Bradley)

direct seeded yellow(Safrane)

direct seeded yellow (??) direct seeded yellow(Montclair)

direct seeded red (??) direct seeded transplants(Red Defender)

Bacterial Bulb Rot (%

)

Effect of Premature Mortality "Dying Standing Up" on Bacterial Bulb Rot:End of Season Field Survey, Elba, 2015

Lodged Dying Standing Up

c‐f

ef efef

def

cdecd

bc

ab

f

a

f

24%8%23%12% 5.5%

2.5%

2x

2.2x

1.4x

1.2x

2.2X

4x

Hoepting 2015



Effect of Dying Standing Upon Bulb Rot

8.9

16.4

0

2

4

6

8

10

12

14

16

18

20

Lodged Dying Standing Up

Bacterial Bulb Decay (%)

A

B

Data pooled across 6 fields1200 bulb sample

2x

Plants that died prematurely standing up had twice as much bulb rot at harvest

Hoepting 2015

1. To evaluate different fungicides and chemical classes for their efficacy against Stemphylium leaf blight (SLB).• FRAC Group 3, 7, 9, 11, 12, 22, 29 and M3

• Quadris vs. Quadris Top

• Inspire Super vs. Inspire

• Pristine vs. Cabrio and Endura

2. To optimize Scala for control of SLB.

Additional Thoughts


Stemphylium Leaf Blight in New YorkObjectives


Stemphylium Leaf Blight in New YorkTreatments

Tradename & Rate/Acre Active Ingredient FRAC group

Scala 18 fl oz pyrimethanil 9

Quadris 12 fl oz azoxystrobin 11

Quadris Top 14 fl oz azoxystrobin+ difenaconazole

113

Pristine 18.5 oz Pyraclostrobin+ boscalid

117

Cabrio 12 oz pyraclostrobin 11

Endura 6.8 oz boscalid 7

All treatments applied with Induce 0.125% v/v



Tradename & Rate/Acre Active Ingredient FRAC group

Inspire Super 20 fl oz Cyprodinil+ difenoconazole

93

Inspire 7 fl oz difenoconazole 3

Merivon 9 fl oz pyraclostrobin+ fluapyroxad

117

Tilt 8 fl oz propiconazole 3

Switch 14 fl oz Cyprodinil+ fludioxomil

912

Omega 1 pt fluazinam 29


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3



Tradename & Rate/acre Active Ingredient FRAC group

Gavel 2 lb Zoxamide+ mancozeb

22M3

Pipeline products:

Luna Tranquility 16 fl oz(no Induce)

Fluopyram+ pyrimethanil

79

Fontelis 1.5 pt penthiopyrad 7

Untreated checks:

DM & OT sprays Phosphorus acidRadiant/Agri‐Mek

33

No pesticides


Methods

• Commercial onion field, Elba, NY

• Pungent yellow direct seeded onion, cv. Gunisen

• RCBD with 18 treatments & 5 replications

Methods

• Weekly applications commencing at first sign of SLB• Jul‐18, 24, Aug‐1, 8, 13 (~50% lodging)

• CO2 backpack sprayer; Teejet 8005 VS; 40 gpa; 31‐38 psi

Aug‐6 & 20:

• 6 randomly selected plants per plot

• No. SLB lesions per plant

• % leaf dieback

Aug‐20 & 30:• Green rating per plot (scale 0‐100)

Methods: Data Collection

SLB Score:

= [Aug‐6 % leaf dieback/plant]

+ [Aug‐6 Total spots per 10 plants]

+ [Aug‐20 % leaf dieback/plant]

+ [Aug‐20 Total spots per 100 leaves]

+ [100‐Aug‐20 green rate]

+ [100‐Aug‐30 green rate]

• High score means high disease

• Low score means low disease

Methods: Data CollectionStemphylium Leaf Blight in New

YorkStemphylium Leaf Blight in New

YorkResults: SLB Score

152

182188 193 194 194 197

203212

231 232239 244 245

273285

303

345

0

50

100

150

200

250

300

350

400

SLB Score

a

gh

defde

711

79

311

39 7 7

11

912

11

33

33

71120

22M3

7119M3M5

9

b

gg

h

gg

efg

bbc

cde

g

defcd

fg

higher score = higher disease same as best treatment

same as Untreated

(maintenance)

Hoepting 2015

Luna Tranquility

Merivon

Untreated no pesticides

Untreated OT/DM

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4


Stemphylium Leaf Blight in New YorkResults: Green Rating (Aug‐30)

80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

10

0

10

20

30

40

50

60

70

80

90

100

Green Rating Scale (out of 100)

aab

abcab

cd

bcd

711

79 3

11

39

7

7

g g g

f

h

11

912

1133

d

de

ef

dcd

ef

3 3

711

2022M3

7119M3M5

ef

9

same as best treatment

same as Untreated

(maintenance)


Hoepting 2015

Luna Tranquility

Merivon

Inspire Super

QuadrisTop

Untreated OT/DM

Fontelis

Endura

Green Rating strongly correlated with SLB score

Top 5 SLB scores

Bottom 4 SLB scores


Stemphylium Leaf Blight in New YorkResults:

No. SLB lesions per leaf (Aug‐20)

0.08 0.08

0.12

0.17 0.17

0.21

0.25 0.25 0.25

0.29 0.29

0.35

0.37 0.37

0.42 0.420.43

0.46

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Total N

o. SLB lesions per leaf (Aug‐20)

Total Number SLB LEsions (tan, purple & black) per Leaf (Aug‐20)

e

a

a‐e

e

ab

a‐d

cde

de

a‐e

abab

a‐e

cde

abc

a‐e b‐e

abc

b‐e711

79

311

39

7

7

11

912

1133

3

3

711

20

22M3

79M3M5

9


same as Untreated

0.08 0.08

0.12

0.17 0.17

0.21

0.25 0.25 0.25

0.29 0.29

0.35

0.37 0.37

0.42 0.420.43

0.46

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

Total N

o. SLB lesions per leaf (Aug‐20)

Total Number SLB LEsions (tan, purple & black) per Leaf (Aug‐20)

e

a

a‐e

e

ab

a‐d

cde

de

a‐e

abab

a‐e

cde

abc

a‐e b‐e

abc

b‐e711

79

311

39

7

7

11

912

1133

3

3

711

20

22M3

79M3M5

9


same as Untreated

Top 6 SLB scores

Bottom 4 SLB scores

No. SLB lesions/plant strongly correlated with SLB score



Relationship: Green (Aug 30) & No. SLB lesions per leaf (Aug‐20)

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60 70 80 90

Total N

o. o

f Sp

ots (tan, black & purple) per 100 leaves (Aug‐20)

Green Rating (scale 0‐100) per plot on Aug‐30

Number of Target Spots Aug‐20 vs. Green Rating Aug‐30

Green rating: < 10%No. spots: > 40/100

Green rating: > 80%No. spots: < 30/100

Untreated (with maintenance)Luna tranquilityFontelisMerivonInspire Super

There was a lot of “noise” in the relationship between Green Rating and No. SLB lesions per plant…


Stemphylium Leaf Blight in New YorkSLB Lesions

… due to variability in kinds of SLB lesions (shown here).

Classic large spot

Multiple small spots

Nondescript necrosis & tan spot

Untreated (maintenance DM/OT) Untreated (no pesticides)


Stemphylium Leaf Blight in New YorkResults: Untreated (Aug‐30)

Luna Tranquility FontelisMerivon


Stemphylium Leaf Blight in New YorkResults:

Best Treatments (Aug‐30)

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80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

7119M3M5

ef9


same as Untreated

(maintenance)

Hoepting 2015

Group 7 provided best control of SLB.5 out of top 7


Untreated OT/DM

FRAC Group 7



80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)

Hoepting 2015

Group 3 provided best control of SLB.2 out of top 4


Untreated OT/DM

Inspire

Tilt

Inspire Super

QuadrisTop

FRAC Group 3

80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)



Hoepting 2015

Merivon (11+7) performed significantly 2.6 times better than Cabrio (11) Q

uadris

Merivon

Cabrio

QuadrisTop


Untreated OT/DM

80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)



Hoepting 2015

Cabrio


Untreated OT/DM

Endura (7) performed significantly better than Cabrio (11) & Pristine (7 & 11)

PristineEndura

80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)



Hoepting 2015

Quadris Top (11 + 3) performed significantly 2.7 times better than Quadris (11). Q

uadris

QuadrisTop


Untreated OT/DM

Cabrio (11) Pristine (7+11)Endura (7)



Results (Aug‐30): Pristine vs. Cabrio & Endura

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Quadris (11) Quadris Top (11+3)



Results (Aug‐30): Quadris vs. Quadris Top



80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)

Hoepting 2015

Luna Tranquility (7 + 9) was significantly better than Scala (9).


Untreated OT/DM

Scala

Luna Tranquility

Scala (9) Luna Tranquility (9+7)



Results (Aug‐30): Scala vs. Luna Tranquility



80.878.6 77.4 76.2

71.2

67.6 67.2 66.664.6

62

54.6 54 52.6

46

31.229.6 28.6

18.2

10

0

10

20

30

40

50

60

70

80

90

100


aab abc

ab

cd

bcd

711

79

311

39

77

g g

h

f

g

h

11

912

1133

d

de

ef

dcd

ef

33

711

2022M3

79M3M5

ef9


same as Untreated

(maintenance)

Hoepting 2015


Untreated OT/DM

Group 12, 20, 22 and 33 provided moderate or poor activity against SLB.


Stemphylium Leaf Blight in New YorkFungicide Summary

• Best fungicides for managing SLB appear to belong to FRAC group 7 and 3

• Merivon (11 + 7) was significantly better than Cabrio (11) and Endura (7)

• Quadris Top (11 + 3) was significantly better than Quadris (11)• Luna Tranquility (7 + 11) was significantly better than Scala (9)

• Appears that FRAC group 11 fungicides are slipping in their ability to control SLB

• Group 9, 12, 20, 22 and 33 provided moderate to poor control of SLB.

• Challenge: Design effective fungicide program that follows rotation restrictions for resistance management to preserve useful life of FRAC group 3 & 7.


Stemphylium Leaf Blight in New YorkPay Attention to FRAC Groups

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Optimizing Scala

Botrytis Leaf Blight Purple Blotch

Relative

performanceFungicide

Rank

ScoreRelative

performanceFungicide

Rank

Score

BEST 1 Scala 9 fl oz + Bravo 1.5 pt 12 BEST 1 Scala 9 fl oz + Bravo 1.5 pt 15

2 Bravo 3 pt 13

2nd

Best

2 Scala 18 fl oz 23

2nd

Best

3 Bravo 1.5 pt + Penncozeb

3 lbs20 3 Rovral 1 pt 24

Mediocre

4 Endura 6.8 fl oz 29 4 Switch 14 oz 26

5 Rovral 1 pt 30

Mediocre

5 Endura 6.8 fl oz 37

6 Switch 14 oz 31 6 Quadris 12.3 fl oz 40

7 Scala 18 fl oz 32 7 Pristine 18.5 fl oz 43

POOR

8 Pristine 18.5 fl oz 39 8 Cabrio 12 fl oz 44

9 Cabrio 12 fl oz 41

POOR

9 Bravo 3 pt 47

9Penncozeb 3 lbs 41 9

Bravo 1.5 pt + Penncozeb

3 lbs47

10 Quadris 12.3 fl oz 48 10 Penncozeb 3 lbs 50


2004‐2011 Relative Performance of Fungicides for BLB & PB


2013 Results: Stemphylium Leaf Blight

2.7

66.4 6.4

9.19.8

10.3 10.5 10.711.1 11.3

14.314.8

15.9

16.9 17.1

0

2

4

6

8

10

12

14

16

18

Cummulative SLB/PB score

Stemphylium Leaf Blight/PB Total Disease Score (2 data points)

84% control

63% control

40% control

16% control

BEST! 2nd

BEST!MEDIOCRE FAIL!

1 2 3 3

mancozeb

Rovral

Bravo

Treatments with Scala

Bravo, Rovral & mancozeb failed 6

10

1720 20

29 29

4145 45

53 5456

63

0

10

20

30

40

50

60

70

Total R

ank Score*

Overall Plant Health: % leaf dieback, No. green leaves per plant, green rating (2x), % dying standing up


Stemphylium Leaf Blight in New York2014: Downy Mildew & SLB

Perfect score : 5Worst score: 70

Treatments with Scala


Stemphylium Leaf Blight in New YorkOptimizing Scala

Rate of Scala (per acre)

Tank mix partner

18 fl oz

18 fl oz Induce 0.125% v/v

18 fl oz Mancozeb 3 lb

9 fl oz Mancozeb 3 lb

9 fl oz Bravo 1.5 pt

9 fl oz Rovral

Luna Tranquilty Scala + FRAC 7

2015 Treatments


Stemphylium Leaf Blight in New YorkScala Results: SLB Score

132

195

211 214224

229

258

283

323

0

50

100

150

200

250

300

350

Luna Tranquility16 fl oz

Scala 9 fl oz +Rovral 1 pt

Scala 18 fl oz +Induce

Scala 9 fl oz +mancozeb


Scala 9 fl oz +Bravo 1.5 pt

Scala 18 fl oz Untreated (withmaintenance)

Untreated (nopesticides)

Target Spot Score

f

e

a

cdde

de de

bc

b

higher score = higher disease same as Untreated

(maintenance)

Best Treatment

WorstTreatment

Hoepting 2015

Scala 18 fl oz not significantly different than untreated checks.

Scala 18 fl oz

1/25/2016

8



132

195

211 214224

229

258

283

323

0

50

100

150

200

250

300

350









Target Spot Score

f

e

a

cdde

de de

bc

b


(maintenance)

Best Treatment

WorstTreatment

Hoepting 2015

Adjuvant significantly improved control of Scala

Scala 18 fl oz

Scala 18 fl oz+ 0.125% v/v

Induce

Scala 18 fl oz Scala 18 fl oz + Induce 0.125% v/v



Results (Aug‐30): Effect of Adjuvant with Scala



132

195

211 214224

229

258

283

323

0

50

100

150

200

250

300

350









Target Spot Score

f

e

a

cdde

de de

bc

b


(maintenance)

Best Treatment

WorstTreatment

Hoepting 2015

Scala 18 fl ozScala 18 fl oz+ mancozeb

Mancozeb significantly improved control of Scala; no difference between Scala 18 & 9 fl oz.

Scala 18 fl oz Scala 18 fl oz + mancozeb Scala 9 fl oz + mancozeb



Results (Aug‐30): Effect of Mancozeb with Scala



132

195

211 214224

229

258

283

323

0

50

100

150

200

250

300

350









Target Spot Score

f

e

a

cdde

de de

bc

b


(maintenance)

Best Treatment

WorstTreatment

Hoepting 2015

Scala 18 fl oz

Scala 9 fl oz+ Rovral

Rovral significantly improved control of Scala; performed significantly better than Bravo 1.5 pt + Scala 9 fl oz

Scala 18 fl oz Scala 9 fl oz + Bravo 1.5 ptScala 9 fl oz + Rovral 1 pt



Results (Aug‐30): Effect of Rovral/Bravo with Scala

1/25/2016

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Stemphylium Leaf Blight in New YorkScala Summary

Efficacy of Scala can be improved by:

• Using with an adjuvant

• Using with mancozeb

(no difference between 9 & 18 fl oz)

• Using with Rovral 1 pt

Other Considerations

Untreated (maintenance DM/OT) Untreated (no pesticides)


Stemphylium Leaf Blight in New YorkResults: Untreated (Aug‐30)

Total SLB:

4.3per 10 leaf

Total SLB:

3.5per 10 leaf

Stress appears to be an important factor in development of SLB



Downy MildewFungicide Evaluation, 2015

Trial started at first detection of downy mildew



Downy MildewFungicide Evaluation, 2015

4 weeks later…

Why are the grower’s onions still green?

1/25/2016

10

Grower fungicide spray programDate Fungicides FRAC

GroupDM

controlSLB

controlFoliar Feed

Jun‐22 Mancozeb 3 lb M3 Yes No

Jul‐2 Viathon 32 fl oz+ Scala 16 fl oz

3 + 339

Yes (33)No

Yes (3)Yes

Xtra Power 1 qt

Jul‐10 Viathon 32 fl oz+ Rovral 1 pt

3 + 33E3

Yes (33)No

Yes (3)Yes

Jul‐17 Mancozeb 3 lb+ Inspire Super 20 fl oz

M33 + 9

YesNo

NoYes

EleMax

Jul‐24 Merivon 5.5 fl oz 7 + 11 Yes (11) Yes

Jul‐31 Viathon 3 pt+ Inspire Super 1.25 pt

3 + 333 + 9

Yes (33)No

Yes (3)Yes

EleMax

Aug‐7 Ridomil Gold Bravo 2.5 pt+ Scala 1 pt

49

YesNo

NoYes

EleMax

Aug‐13 Ridomil Gold Bravo 2 ptQuadris 12.8 fl oz

411

YesYes

NoYes

EleMax

Aug‐21 Viathon 3 pt 3 + 33 Yes (33) Yes (3) Xtra Power

Aug‐28 Foliar phosphite 4 pts + Inspire Super 20 fl oz

333 + 9

YesNo

NoYes

Sep‐4 Mancozeb 3 lb+ Rovral 1 pt

M3E3

YesNo

NoYes

Elba, NY: 2015


GroupDM

controlSLB

controlFoliar Feed



3 + 339

Yes (33)No

Yes (3)Yes

Xtra Power 1 qt


3 + 33E3

Yes (33)No

Yes (3)Yes


M33 + 9

YesNo

NoYes

EleMax



3 + 333 + 9

Yes (33)No

Yes (3)Yes

EleMax


49

YesNo

NoYes

EleMax


411

YesYes

NoYes

EleMax



333 + 9

YesNo

NoYes


M3E3

YesNo

NoYes

Elba, NY: 2015

Very good downy mildew fungicide

program


GroupDM

controlSLB

controlFoliar Feed



3 + 339

Yes (33)No

Yes (3)Yes

Xtra Power 1 qt


3 + 33E3

Yes (33)No

Yes (3)Yes


M33 + 9

YesNo

NoYes

EleMax



3 + 333 + 9

Yes (33)No

Yes (3)Yes

EleMax


49

YesNo

NoYes

EleMax


411

YesYes

NoYes

EleMax



333 + 9

YesNo

NoYes


M3E3

YesNo

NoYes

Elba, NY: 2015

“Front‐loaded” very good SLB fungicide program (group 3); weak on Aug 7 & 13, Sep‐4.What else is going on?


GroupDM

controlSLB

controlFoliar Feed



3 + 339

Yes (33)No

Yes (3)Yes

Xtra Power 1 qt


3 + 33E3

Yes (33)No

Yes (3)Yes


M33 + 9

YesNo

NoYes

EleMax



3 + 333 + 9

Yes (33)No

Yes (3)Yes

EleMax


49

YesNo

NoYes

EleMax


411

YesYes

NoYes

EleMax



333 + 9

YesNo

NoYes


M3E3

YesNo

NoYes

Elba, NY: 2015

Six applications of foliar feed

Does foliar feeding help plant to fend off disease?

Feed a cold…


Stemphylium Leaf Blight in New YorkNext Steps

• More fungicide trials…• spray timing (when to start & finish)

• do foliar nutrients help?

• relationship to plant stress

• Relationship to Botrytis leaf blight

• Develop a scouting protocol to quantify/rate SLB in grower fields

• Evaluate best performing SLB fungicides for their efficacy against Botrytis Leaf Blight

York Featuring Managing StemphyliumLeaf Blight Onion ......1/25/2016 1 New York Update: Featuring...

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Transcript of York Featuring Managing StemphyliumLeaf Blight Onion ......1/25/2016 1 New York Update: Featuring...