Updates on Fire Blight Research and Management Options

Updates on Fire Blight Research and Management Options

Mohammad Babadoost

University of Illinois

Email: babadoos@illinois.edu

Major Apple Disease Problems in

Illinois in 2011 _______________________________________

Scab

Fire Blight*

Fruit Rots

Bitter Rot

White Rot

Fire Blight Symptoms ___________________________

Blossom blight

Fruit blight

Shoot blight*

Canker

Rootstock blight

Blossom blight

Fruit blight

Shoot blight

Canker

Rootstock blight

Apple fire blight – losing trees

APAnet

Apple Fire Blight in Illinois ___________________________________________

2008: widespread and severe infection

2009: widespread and severe infection

2010: low incidence

2011: low incidence

http://www.caf.wvu.edu/kearneysville/disease_descriptions/fire_blight_disease_cycle.htm Modified by J. Norelli

Control of Fire Blight of Apple _________________________________________

Copper application at silver-tip

Streptomycin applications at bloom

Streptomycin application as

predicted by MARYBLIT or

Cougar Blight

Streptomycin application after hail

damage

Control of Fire Blight of Apple _____________________________________

Streptomycin is the most

effective chemical for control

of fire blight

Streptomycin for Fire Blight of Apple ___________________________________________

1950s: Streptomycin use began

1971: Streptomycin-resistance in

California

By 2010: Streptomycin-resistance in

western US, Michigan, New York,

Canada, Israel

Apple Fire Blight in Illinois ______________________________________

In 2010, we initiated a research

to determine whether there are

streptomycin-resistant strains

of the causal bacterium

(Erwinia amylovora)

Orchards

surveyed in

2010 (24)

Orchards

surveyed in

2011 (35)

Isolating bacteria from blossoms

Grind tissue

Remove bark

Grind tissue

Isolating bacteria

from shoots

PCR Identification:

Primers AJ 75/76; targeting plasmid pEA 29 (McManus and Jones, 1995)

MK1

68D

42B

45E

47C

75A

48A

NOT EA

28A

165E

166B

EA

Moist Chamber (7 days)

5 replications/ isolate

Pathogenicity test in pear

Pathogenicity test in pear

IL E. amylovora isolates (7 days)

2010- E. amylovora Pathogenicity on immature pear fruit 7 days post inoculation ( 107 CFU )

County Isolate Mean Lesion

Diameter (mm) County Isolate

Mean Lesion

Diameter (mm)

Boone 193b 0.3 Macoupin 10c 4.5

196b 0.3

Marshall

108d 3.7

Calhoun

49c 3.8 118b 2.6

45d 2.2 111c 1.0

15a 1.7 Putnam 170c 1.2

68d 1.7 Sangamon 84d 1.9

26d 1.3

St. Clair

93c 4.6

38c 1.3 89a 4.1

Champaign 2a 1.7 128c 3.7

Jersey

75a 4.3 127b 3.0

30b 3.0 Woodford 165e 2.5

28b 2.6 mk1 0.9

2011- E. amylovora Pathogenicity on immature pear fruit 7 days post inoculation ( 107 CFU )

County Isolate

Mean Lesion

Diameter (mm) County Isolate

Mean Lesion

Diameter (mm)

Boone

6951 5.7 Kane 4951 2.5

7101 5.7 Madison 5472 4.9

7071 5.2 Marshall

7841 5.3

Calhoun

7651 5.5 7501 4.1

7621 5 Peoria 7461 4.9

6081 4.4 Putnam 7691 4.8

7571 3.9 St Clair

5461 6.6

7751 3.2 5752 5.3

Champaign 4802 1.8 Union

5152 3.2

Jackson 5341 3.9 5232 3.2

Jersey

6002 4.3 Woodford

7711 8.9 *

7671 3.1 7731 5

7531 3 mk1 2.6

Results of Pathogenicity Tests ________________________________________

All Illinois isolates were pathogenic,

the lesion sizes were different in

pear. We are investigating the

differences.

Testing Erwinia amylovora

Isolates for

Streptomycin-Resistance

Agri-Mycin 17 Erwinia amylovora isolates:

Illinois isolates Michigan streptomycin-

resistant 0 ppm 25 ppm

50 ppm 100 ppm

2010 Streptomycin Resistance Status Report

County

Strikes

Erwinia amylovora

isolates (no)

Erwinia amylovora colony

50ppm

Boone 15 9 0

Calhoun 36 63 0

Champaign 6 12 0

Jersey 29 33 0

Kane 11 8 0

Macoupin 9 13 0

Madison 10 0 0

Marshall 16 24 0

McHenry 6 3 0

Peoria 11 2 0

Putnam 10 10 0

Sangamon 6 4 0

St. Clair 42 31 0

Winnebago 4 5 0

Woodford 7 8 0

Totals 218 225 0

2011 Streptomycin Resistance Status Report

County

Blossoms &

Strikes

Erwinia amylovora

isolates (no)

Erwinia amylovora colony

50ppm

Boone 23 10 0

Calhoun 98 25 0

Champaign 49 18 0

Dekalb 0 - -

Jackson 22 8 0

Jefferson 7 0 -

Jersey 54 11 0

Kane 11 3 0

Macoupin 6 - -

Madison 11 5 0

Marshall 29 8 0

McHenry 15 0 -

Peoria 29 7 0

2011 Streptomycin Resistance Status Report- continues

County

Blossoms &

Strikes

Erwinia amylovora

isolates (no)

Erwinia amylovora colony

50ppm

Piatt 1 0 -

Pope 0 - -

Putnam 16 3 0

Randolph 3 0 -

St. Clair 55 16 0

Union 39 12 0

Winnebago 5 0 -

Woodford 15 3 0

Total (21) 488 129 0

Studies during 2010-2011

showed no streptomycin-

resistance of fire blight

bacterium in Illinois. The

study will continue in 2012.

Kocide 3000 (0.23 g/ L)

Kocide-3000 Erwinia amylovora isolates:

2010 and 2011 Control

We are still evaluating the

isolates for resistance to

copper compounds, but so

far, no resistance has been

detected.

Chemical Testing in Lab - Results ___________________________________________

85 IL E. amylovora tested in 2010 and 2011

No resistance to streptomycin at 25 ppm

No resistance to oxytetracyline

(Mycoshield) at 50 ppm

No resistance to Kasugomycin

(Kasumin 2L) at 100 ppm (under study)

No resistance to Kocide-3000 at 0.16 mM

No resistance to copper sulfate at 0.16 mM

Field testing of chemicals for control

of fire blight of apple ___________________________________________

Testing in 2011

UIUC experimental orchard, Urbana (IL)

Jonathan apple, inoculated

Trees were inoculated twice

Chemicals were applied 24 pre-inoculation

and 24 post- inoculation

2011 Field Testing of Chemicals for Fire Blight Control

Treatment Application time No. Infected Clusters (120/tree)

Seranade Max Pre-inoculation 28.7 bcde

Serenade Max Post-inoculation 46.3 a c

Blightban A506 Pre-inoculation 37.7 abc

Blightban A506 Post-inoculation 41.3 ab

Control (no inoculation) - 37.3 abc

Control (inoculation) - 35.0 abcd

Mycoshield Pre-inoculation 39.7 abc

Mycoshield Post-inoculation 29.3 bcde

Agrimycin 17 Pre-inoculation 27.3 bcde

Agrimycin 17 Post-inoculation 19.3 e

Kasumin 2L Pre-inoculation 19.3 e

Kasumin 2L Post-inoculation 21.0 de

Ary-0416-06 Pre-inoculation 26.0 cde

Ary-0416-06 Post-inoculation 16.3 e

The information is form

the research results by

Andre Jurgens

(Graduate Student)

Questions/

Comments