guiding management of apple scab, fire blight, sb&fs and ... · 3/1/2019 · rimpro fruit...

Guiding Management of Apple Scab, Fire Blight, SB&FS and Marssonina Leaf and Fruit Blotch

with RIMpro and NEWA Models

Srdjan G. Acimovic

HVRL Workshop on Pre-Bloom Decision Making for Your Orchard

8 March 2019

Hudson Valley Research Laboratory

Outline

1. Apple Scab

2. Fire Blight

3. Cedar Apple Rust

4. Marssonina Leaf Blotch/Fruit Spot

5. Sooty Blotch & Flyspeck

1. Apple Scab

(Venturia inaequalis)

Symptoms


Fruit Scab


For NY Growers We:

• Monitored pathogen maturation - biofix

• Deliver scab & fire blight predictions

with spray rec-s:

– 19 E-mails (2017)

– 22 E-mails (2018)

• Acimovic Lab blogs to subscribers:

– 43 blogs (2017)

– 44 blogs (2018)

• Published four articles in Fruit Quarterly

• Continue use & increase RIMpro base


Monitor Ascospore Release- Ascospores vs. Conidia -


Cornell’s HVRL Extension & Outreach- Apple scab biofixes, RIMpro -

• Ascospore maturity in leaf litter

– Highland 29 Mar

– Rexford 7 Apr

– North Peru 11 Apr

– Maturation is predicted when RH > 70%

– Speed and amount of maturation assumed proportional to the accumulated temperatures above 32°F.

– 50-60 spores an economic threshold in tower


What is What?


A - vertical light blue line marks the current date and time within that day.B - White camel hump “Germinating spores” are cumulative number of ascospores that germinate over timeand use the right-side vertical Y-axis scale that is labelled “Discharge”.C - Small yellow-black bars (zoom-in) show number of spores ejected from leaf litter in the orchard duringeach one-hour interval.D - Red curve is the RIM infection value, when divided by 100, is percent of the total season’s ascosporesthat are likely to cause infection in any given infection period. Use the vertical Y-axis “RIM Infection Value”

What is What?

E - Orange area “Primary stroma” are scab lesions that were initiated by infection fromgerminating spores and are incubating after which scab lesions will become visible. Incubatinginfections are worth noting because, if no fungicide was in place before the infection event,some incubating infections can be eliminated by using Kick-back fungicides.F - Light red area in “Maturation” graph is proportion of mature ascospores that are ready fordischarge with wetting events whereasG - Dark red area shows the proportion of immature ascospores remaining in leaf litter.


Monitor Ascospore Release- Results, New York -


Start of Primary Scab Season- Results, New York -


End of Primary Scab Season- Results, New York -


RIMpro Fruit Quarterly Article- Winter 2019 -

• You can omit 1-3 unnecessary fungicide sprays in 2017 & 2018• 1 or 2 additional sprays necessary to control scab before scab

season end• $310,000 – $930,000 for 12,375 acres in east NY

Savings

• 2017 & 2018 RIMpro use: omit 1-3 unnecessary

sprays in early spring

• If $25/A for each fungicide spray, save $310 K –

$930K for the total of 12,375 A of apples in eastern

NY

• RIMpro allowed better protection from scab than

NEWA by requiring 1 or 2 additional sprays

necessary before primary scab season end


Year Differences in Scab Infections- 2016 -


Year Differences- 2017 -

H

F

G

T

C

P

K

B

L

P

F

F

C

G

T


Year Differences- 2018 -

HIG

24

Apr

T

C

P

K

B

L

PF

14

May

FC

25

May

GT

7

Apr


2. Fire Blight Basics – Erwinia amylovora- Risk of Production -

Balaž et al. 2008


• Period of fire blight susceptibility from very few first flowers

open on pear/apple earliest cultivars/s on you farm, all the way

up until the terminal buds set on shoots on your trees.

Ooze on Tissue Before Blight Occurs ! - Spreads Infection Further -


http://www.omafra.gov.on.ca

Photo by Anna Wallis


Blossom, Shoot Blight, Cankers, Rootstock Blight- Ooze, Too Late Then –

High density plantings

extremely vulnerable

due to short limbs -

fire blight moves into

branches and trunk

fast.

• Spindle systems

(~1000 - 2000 /A)

• Susceptible cultivars: Mutsu, Fuji, Gala,

Gingergold, Pink Lady,

Idared, Jonathan,

Monroe, Paulared, Rome,

SweeTango, NY-1, NY-2

• Susceptible

rootstocks: M.9, M.26

• Trees < 6-8 yr old.

High Density Planting = No FB Tolerance- Dwarf trees, Susceptible Rootstocks -


FB Infection: Sequence & Requirements

1. Assumes an abundance of inoculum

2. Opening flowers (new) must be open with stigmas and petals intact (stigmas exposed for colonization, flowers in petal fall are resistant);

3. Accumulate enough heat units in bloom for inoculum to reach threshold: min. 198 degree hours (DH) > 65°F (110 DH > 18.3°C) within the last 80 degree days (DD) > 40°F (44.4 DD > 4.4°C) for apples (This defines the epiphytic infection potential for the oldest open and, hence, most colonized flower in the orchard)

4. Wetting event to wash bacteria flower from stigmas to nectar glands dew or ≥ 0.01 inch (0.25 mm) of rain, or ≥0.10 inch (2.5 mm) of rain the previous day

5. Average daily temperature of ≥ 60°F (15.6°C) as it influences the rate at which the bacteria migrate into the nectar glands as well as the multiplication of bacteria needed to establish infections)


• MaryBlyt EIP (Epiphytic Infection Potential) is an index depicting infection risk for enough

heat units (degree hours >65 F).

• Threshold for infection is EIP ≥ 100: EIP is calculated by expressing the number of

DH>65ºF accumulated over the last 80 (apple) DD>40F as a percentage of 198 DH>65ºF,

which represents the threshold for infection.

High RH in 2016?



RH in 2018- Fire Blight -

• Since infections occur within minutes in response to a single rain or dew event, it

is also characteristic for most symptoms to develop simultaneously.

• This is the reason why symptoms appear suddenly rather than gradually and

show about the same degree of blight when they first appear.

NEWA Fire Blight Model 2016 - Summary


Maryblyt 7.1 on PC


NEWA’s Maryblyt - EIP


EIP in NEWA


• Model Risk Level:• Low Risk= yellow ‘L’: occurs when there is bloom

• Moderate Risk = orange ‘M’ occurs when there is bloom and one of the following occur: 1) 198 DH >65F or >100 EIP, 2) Wetting event (like existing model), or 3) Average temp > 60F

• High Risk = red ‘High’ occurs where there is bloom and two of the following occur: 1) 198 DH >65F or >100 EIP, 2) Wetting event (like existing model), or 3) Average temp > 60F

• Infection Risk = red ‘Infection’ occurs where is bloom and all of the following occur: 1) 198 DH >65F or >100 EIP, 2) Wetting event (like existing model), and 3) Average temp > 60F

RIMpro Fire Blight Model- Why and When to Spray? -


Spray Antibiotics in Bloom 2019- Considerations -

• Use NEWA/RIMpro to time strep sprays and avoid control failures

• Cover up to 24 h after the event (streptomycin + Regulaid)

• Precise timing = high efficiency

• Bacteria grow fast on flowers at warm weather (> 65 F)

• Antibiotic protects only blossoms that are open at the spray time

• After drying, antibiotic will not redistribute

• Spray just before wetting (all open flowers protected during infection)

• LOOK NEWA EIP = need for additional treatment

• Reapplication protects newly opened flowers before the next rain


Management Strategy – Prevent Secondary Infections- Mid Summer -

Fact: Bacteria inside flowers, shoots, wood, fruit

Goal: Prevent/ Reduce inoculum spread

• Copper before/ after pruning – lower doses, cultivar dependent• Limit spread to shoots

• CAUTION: Russeting

• Apogee: 6-12 oz/100 gal; 3-6 oz for trees <5 years• 1-3 inch shoot growth (late bloom)

• 14-21 days later

• Stunt growth

• Stop new growth

• Limit new infections

• Bridge to terminal bud set



3. Cedar Apple & Quince Rust- CAR, QR, Gymnosporangium spp. -

• QR infects apple fruit from

TC/PK bud to PF/FC

• CAR on apple leaves infects

4 - 6 weeks after PF

• First symptoms in Highland on:

• 17 May 2017

• 10 May 2018

• Eastern red cedar

• Juniperus virginiana

Not Only One Species


Keep in Mind for Rust

• Rain expansion and drying of orange horns occurs 8-10 times. Each time horns push out more and expose more teliospores until the reserves are depleted

• Before apple infection, adequate moisture needed in a temperature 8-24 C (46-75 F) to allow for formation of basidiospores on cedar galls.

• Basidiospores will infect apple when susceptible leaf and fruit tissues are wet for certain lengths of time at certain temperatures

• Apple leaves most susceptible to infection 4-8 days old

• Fruit susceptible from TC to BL.

• If pressure high: spray fungicides from TC – FC

• Infects apple green tissue 3-5 h after first warm rain

• Symptoms on apples seen 2-3 weeks after infection event


To Organic or Not?

• Not effective: copper, sulfur, LLS• Start sprays just before orange horns in spring show on cedar galls

• Cut red cedars 500 ft. near orchards = reduce disease pressure

• Suppression (Yoder et al. 2014, 2015):

• Regalia 4 qt/A + JMS Stylet oil

• Regalia 2 qt/A, every 7-10 days

• Cueva

• Oso

• Sulfur, LLS not compatible with oil

• Regalia ineffective for apple scab

• Look for:• Find first orange horns on cedar: 25 April 2018, Highland (HIG)

• Symptoms showed on 10 May 2018, Highland (BL)


Apple cv. Rust Resistance


2017 Rust Problem



2018 - The Year of Apple Scab & Rust- 11-71% More Rain -

Rust Infection Prediction- Easy -

Authored by R. C. Pearson, H. S. Aldwinckle, and R. C. Seem. Funded in part by an Extension

Service-USDA, IPM Grant.


4. Leaf Spots - Marssonina Leaf Blotch- Marssonina fungus -

Adapted from: Back & Jung 2014, Journal of Medical Mycology 42(3):183-190

Rain and Wind

Rain and Wind

Source: 2013 EPPO

Source:www.arbofu

x.de/sternrusstau-

an-rose.html

2017 & 2018 Problem in NY OrchardsMarssonina sp. (coronaria?); Diplocarpon sp. (mali?)


Fruit Symptoms

- Marssonina sp. -


Monticello NY - JonagoldGardiner NY – Rome


http://www.newfarm-

agriconsult.com/eng/node/191

- Marssonina Prediction Model -- Use Models -


Marssonina Leaf Blotch- History & Control -

Outbreaks & Control• New York, Pennsylvania, Wisconsin, Canada, Brazil, EU, Korea, China

• Particularly wet summers of 2001, 2002, 2010, 2011, 2013, 2017

• Organic orchards & conventional with reduced spray program – but no labelled fungicides (!)

• Low sensitivity to copper fungicides

• Susceptible: Mutsu, Rome, Northern Spy, NY-1, Topaz, Jonagold, Gala, Luna, Honeycrisp

• Effective control: Resistant cultivars

• Eliminate fallen leaves; prune for good air circulation; Fungicides not registered for this disease in NY

that are effective: Mancozeb, Metiram, Topsin M, Thiophanate-Methyl, Merivon. Research:

tebuconazole, hexaconazole, propiconazole, tebuconazole+ benziothiazolinone @ 20-day intervals,

early July - late August; Bordeaux mix + tebuconazole or + propiconazole or + tebuconazole with

benziothiazolinone alternation @ 25 days (Dang et al. 2017)

Epidemiology & Ecology:• Typical symptoms 40~45 days after inoculation

• Successful infection depends on moist incubation at 100% relative humidity, 20ºC, prior to drying

(Lee et al. 2011):

• Severity 72.5% at 3-day moist incubation

• Severity 20.3% at 2-day moist incubation

• Severity 0% at 1-day moist incubation

• Fungus needs extended period of moisture for infection

• Explains disease start after ample rain in June and July

Bohr et al. 2018 - GermanyFrom: www.ecofruit.net/2018/12_Bohr_36-42.pdf

10-12 spray

applications of

each from 10 or

12 Jun - 30 Aug

http://www.ecofruit.net/2018/12_Bohr_36-42.pdf

Gloedes pomigena, Zygophiala jamaicensis, other fungi

5. Sooty Blotch & Flyspeck

- Prediction -


Spores in pycnidia or from sections of the

mycelium are spread by rains during the

late spring and early summer

Ascospores in pseudothecia are

released during rains for 1-2 month

period starting around BL, wind borne

SB & FS Biology

Wilcox & Gotham 1994

• Sooty Blotch:

• Infections start 2-3

weeks after PF

• Symptoms can

develop 3-4 weeks

after PF, or 2 months

or more, common in

late summer or early

fall.

• Superficial fungi

sensitive to RH%

around fruit. Growth is

great at RH 100%;

good 95%, fair at 92%,

poor at 90% percent;

no growth RH 90%

• 64-80ºF (grow well

(very limited < 50ºF (1

or >86ºF

• Flyspeck

• Germinate at

61-83ºF (16-

28ºC)

• No growth

below RH

<95%

• Incubate 2-3

weeks to

several

months

(RH%

around fruit

surface)


Use NEWA’s SB&FS Model- Free -

• Sprays should start

around first cover

and be repeated as

necessary according

to the dominant

weather conditions

and material being

used.

RIMpro’s Prediction Model- If you buy for scab -



1.07% Citric acid

Spray dates for all treatments:

6/11/2018

6/25/2018

7/9/2018

7/21/2018

7/23/2018

8/4/2018

8/18/2018

8/31/2018 - Golden Del. & McIntosh only

9/11/2018 - Golden Del. & McIntosh only

Treatments/Programs:

1- Untreated Check – UTC

2- FungOut @ 3.75 GL/A (9 sprays)


+ Captan 80 WDG @ 2.5 LB/A

4- Captan 80 WDG @ 2.5 LB/A (9 sprays)

5- Grower Standard:

2 X Captan 80 WDG @ 2.5 LB/A

+ Prophyt @ 64 FL/A


+ Topsin M @ 1 LB/A


+ Merivon @ 5.5 FL/A (2nd on 8/31/2018)

1 X Captan 3 lb/A (9/11/2018)

Sooty Blotch & Flyspeck Trial- Spray Programs 2018 -

5/18/2018 3oz Rally + 3lbs Manzate

5/31/2018 3oz Rally

6/19/2018 3oz Rally

Maintenance sprays: Apple scab and cedar apple rust at the beginning of the season, plus these sprays:

Harvested:

8/30/2018 – Ginger Gold

9/21/2018 – McIntosh

9/29/2018 – Golden Delicious

Grower Standard applied on these dates consisted of: 6/11/2018 and

6/25/2018: Captan 80 WDG @ 2.5 LB/A + Prophyt @ 64 FL/A

7/9/2018,7/21/2018, 7/23/2018* and 8/4/2018**: Captan 80 WDG @

2.5 LB/A + & Topsin M @ 1 LB/A8/18/2018 and 8/31/2018: Captan 80

WDG @ 2.5 LB/A + Merivon @ 5.5 FL/A9/11/2018***: Captan 80 WDG

@ 3 LB/A

Devil in the Details

• Grower Standard applied on these dates

consisted of:

• 6/11/2018 and 6/25/2018: Captan 80 WDG @

2.5 LB/A + Prophyt @ 64 fl oz/A

• 7/9/2018, 7/21/2018, 7/23/2018* and

8/4/2018**: Captan 80 WDG @ 2.5 LB/A + &

Topsin M @ 1 LB/A

• 8/18/2018 and 8/31/2018: Captan 80 WDG @

2.5 LB/A + Merivon @ 5.5 fl oz /A

9/11/2018***: Captan 80 WDG @ 3 LB/A

Treatments/Programs:

1- Untreated Check – UTC



+ Captan 80 WDG @ 2.5 LB/A

4- Captan 80 WDG @ 2.5 LB/A (9 sprays)

5- Grower Standard:


+ Prophyt @ 64 FL/A


+ Topsin M @ 1 LB/A


+ Merivon @ 5.5 FL/A (2nd on 8/31/2018)

1 X Captan 3 lb/A (9/11/2018)

*Spray from 21 July was repeated on 23 July because of

2.2 inches of rain after 21 July. We used Topsin on 23

July as the second Topsin spray on 21 July was washed

off completely.

** We applied the third spray of Topsin to avoid more than

2 sprays Merivon at end of trial. Fruit were 55-65 mm in

size at this date.

*** Applications on Golden Delicious and McIntosh trees

only. Spray from 31 August was repeated on 11

September after 2 inches of rain fell between these

dates.


2018 SBFS Results- Ginger Gold, McIntosh, Golden Delicious -

AA

B B B

a a

b

c

c

0

20

40

60

80

100

120

1. UTC 2. FungOut 3. FungOUT+ Captan

4. Captan 5. GrowSTD

Treatment/ Program

Incidence % on Ginger Gold at harvest on 30 Aug 2018 Tukey (P<0.05)

Mean SB (%) Mean FS (%)A A

B

B

B

a a

ab

bc

c

0

20

40

60

80

100

120

1. UTC 2. FungOut 3. FungOUT+ Captan


Treatment/ Program

Incidence Ginger Gold 2-week postharvest (%) Tukey (P<0.05)

Mean SB (%) Mean FS (%)


2018 SBFS Results- Golden Delicious -

A A

B

AB

C

a a

b

b

c

0

20

40

60

80

100

120

1. UTC 2. FungOut 3. FungOUT +Captan


Treatment/ Program

Incidence on Golden Delicious fruit at Harvest (Tukey’s test, 0.05)

Mean SB (%) Mean FS (%) A A

BC

B

C

a a

b

b

c

0

20

40

60

80

100



Treatment/ Program

Incidence on Golden Del Fruit 2-weeks Postharvest (Tukey’s test, 0.05)



AA

BCB

C

a a

b b

c

0

20

40

60

80

100

120



Treatment/ Program

SB&FS Incidence on McIntosh Fruit at Harvest (Tukey’s test, 0.05)

Mean SB (%) Mean FS (%) A A

B

B

C

a a

bb

c

0

20

40

60

80

100



Treatment/ Program

SB&FS Incidence McIntosh Fruit - Two Weeks Postharvest (Tukey’s test, 0.05)


2018 SBFS Results- McIntosh -

Acknowledgements

Donators:Albaugh LLCBrandt Professional AgricultureJentsch Lab, Cornell UniversityPeter Schweitzer, Cornell Genomic Core

Collaborators:Dr. Keith Yoder, Virginia TechDr. Kerik CoxDan Donahue CCE ENYCHPAnna WallisCooley Lab, UMassJon Clements, UMass Cold Spring Orchard Research& Education Center Belchertown, MA

Collaborators:Jeff, Jenny, Joy Crist, Crist Bros OrchardsSeth, Mason & Mac ForrenceForrence OrchardsJay Toohil, Chazy OrchardsRandy Hart, Hart Apple FarmEverett brothers, Everett OrchardsJesse Mulbury, Northern OrchardKevin Bowman, Bowman ApplesPeter Ten Eyck, Indian Ladder FarmsCharles and Phil, M.G. Hurd & SonsRobert & Doug Minard, W.G. Minard and SonsDanny Albinder, Shawn Bixby Hudson River Fruit

Jentsch Lab, Cornell’s HVRLDr. David Rosenberger

Thank You for Attention . . .

Subscribe

blogs.cornell.edu/acimoviclab/

[email protected]

Questions . . .


guiding management of apple scab, fire blight, sb&fs and ... · 3/1/2019 · rimpro fruit...

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