the strawberry advisory system - uf/ifasplantpath.ifas.ufl.edu/classes/plp6404/lectures... · 2015....

The Strawberry Advisory System

Natalia Peres

University of Florida

Department of Plant Pathology

Gulf Coast REC

FL strawberry industry overview

FL ~ 11,000 ac

2nd biggest U.S. producer

15% total production in U.S.

>$400 million industry

Plant City – “Winter strawberry

capital of the world”

9500

220

Strawberry Production Cycle

in West Central Florida

Sept Oct Nov Dec Jan Feb Mar Apr

Peak bloom periods

Land prep / planting

Peak harvest periods

Current major strawberry cultivars in FL

Florida Radiance

64%

Strawberry Festival

16%

Driscoll10%

Treasure2%

Winterstar™ 6%

Other2%

Major Strawberry Diseases in Florida

Anthracnose diseases

Anthracnose fruit rot (Colletotrichum acutatum)

Colletotrichum crown rot (C. gloeosporioides)

Botrytis fruit rot or Gray Mold (Botrytis cinerea)

Powdery mildew (Podosphaerea aphanis)

Angular leaf spot (Xanthomonas fragariae)

Phytophthora crown rot (Phytophthora cactorum)

Charcoal rot (Macrophomina phaseolina)

Major Strawberry Diseases in Florida

Anthracnose diseases

Anthracnose fruit rot (Colletotrichum acutatum)

Colletotrichum crown rot (C. gloeosporioides)

Botrytis fruit rot or Gray Mold (Botrytis cinerea)

Powdery mildew (Podosphaerea aphanis)

Angular leaf spot (Xanthomonas fragariae)

Phytophthora crown rot (Phytophthora cactorum)

Charcoal rot (Macrophomina phaseolina)

Anthracnose fruit rot

(caused by Colletotrichum acutatum)

Disease cycle

Peres, N.A., Timmer, L.W., Adaskaveg, J.E., Correll, J.C. 2005. Life styles of Colletotrichum acutatum. Plant Dis. 89: 784-796.

Botrytis fruit rot or gray mold

(caused by Botrytis cinerea)

Botrytis colonizes senescent foliage

Production of air- borne conidia

on foliage or fruit

Conidia infect flower parts

(stamen and petals)

Infection invades the receptacle as fruit matures

Spread can also be by fruit-to-fruit contact

Disease cycle

October November December January February March

Planting 1st Bloom 1st Harvest 2nd Bloom 2nd Harvest

Standard spray program for control of BFR and AFR in FL

Botrytis

Protective sprays

Bloom

spraysX X X

Late season

sprays

Anthracnose

Captan, Thiram

Captevate/Elevate, Switch, Pristine, Scala

Evaluate infection models developed to predict

the incidence of Botrytis and anthracnose fruit

rots for their effectiveness to time fungicide

applications

Replicated field trials with 2 cultivars during 3

consecutive strawberry seasons

Fungicides applied at variable intervals

according to models

Compared to a standard calendar program and an

untreated control

Development of a disease forecast system

Botrytis models

Botrytis models

Botrytis 2006-07 season

Disease incidence (%)

Treatment # Sprays Sweet Charlie Festival

Calendar standard 20 3.9 d 0.4

Xu model DI=0.5 15 4.1 d 1.0

Bulger-M Captan DI=0.5; Captevate DI=0.7

12 4.1 d 1.1

Bulger-Madden DI=0.5 9 4.6 cd 1.2

Broome DI=0.5 11 5.1 cd 1.5

Xu model DI=0.8 12 6.2 bcd 1.1

Bulger-Madden DI=0.7 8 7.7 bc 1.6

Broome DI=1.4 5 9.1 ab 3.5

Untreated control 0 12.7 a 3.3

Botrytis 2007-08 season

Disease incidence (%)

Treatment # Sprays Sweet Charlie Festival

Xu model DI=0.5 14 0.9 a 0.4

Bulger-Madden DI=0.5 8 1.7 ab 0.4

Calendar standard 16 1.8 ab 0.3

Broome DI=0.5 11 1.9 ab 0.4

Bulger-Madden DI=0.7 4 2.4 bc 0.3

Xu model DI=0.8 12 2.6 bc 0.6

Bulger-M Captan DI=0.5;

Captevate DI=0.710 3.2 bc 0.2

Broome DI=1.4 4 3.8 c 0.6

Untreated control 0 3.9 c 0.8

Disease incidence (%)

Treatment # Sprays Sweet Charlie Festival

Bulger-Madden DI=0.5 3 0.6 0.3

Calendar standard 17 0.6 0.2

Combined anthracnose and

Botrytis fruit rot INF6 0.8 0.4

Forecasted 3 0.8 0.3

Bulger-M Captan DI=0.5;

Captevate DI=0.74 0.9 0.4

Untreated control 0 1.3 0.5

Botrytis 2008-09 season

Anthracnose model

Anthracnose 2006-07 season

Disease incidence (%)

Treatment# Sprays

(captan; Cabrio)Camarosa Festival

Pre-symptom W-Mcaptan or pyraclostrobin

10

(6;4)2.1 a 0.4 ab

Calendar captan or pyraclostrobin

16

(12;4)3.1 ab 0.4 ab

Calendar

captan only

16

(16;0)4.0 ab 0.1 a

Post-symptom W-Mcaptan or pyraclostrobin

6

(4;2)4.8 ab 1.2 bc

Pre-symptom W-Mcaptan only

9

(9;0)5.5 bc 0.5 ab

Post-symptom W-Mcaptan only

5

(5;0)9.4 cd 0.9 bc

Untreated control 0 14.3 d 2.0 c

Anthracnose 2007-08 season

# Sprays Disease incidence (%)

Treatment(captan;

Cabrio)Camarosa Festival

Calendar

captan or pyraclostrobin16

(12;4)15.5 a 5.2 a

Pre-symptom W-Mcaptan or pyraclostrobin

11

(9;2)17.6 ab 6.3 ab

Calendar

captan only

16

(16;0)20.2 abc 5.9 a

Post-symptom W-Mcaptan or pyraclostrobin

8

(6;2)24.7 bc 7.9 ab

Pre-symptom W-Mcaptan only

11

(11;0)27.6 c 9.8 bc

Post-symptom W-Mcaptan only

9

(9;0)38.4 d 13.4 c

Untreated control 0 58.5 e 35 e

Anthracnose 2008-09 season

Disease incidence (%)

Treatment # Sprays Camarosa Festival

Calendar captan or pyraclostrobin 17 0.8 a 0.2

Calendar

captan only 17 1.1 a 0.2

Pre-symptom W-Mcaptan or pyraclostrobin 5 1.5 a 0.3

Combined anthracnose and

Botrytis fruit rot INF 5 1.8 a 0.8

Post-symptom W-Mcaptan or pyraclostrobin 5 2.0 a 0.4

Untreated control 0 8.3 b 0.4

Treatments and thresholds selected to

develop a web-based disease forecast system

Botrytis: Bulger-Madden DI > 0.5

Anthracnose: Wilson-Madden INF > 0.15; INF > 0.5

(pre-symptom)

Length of most recent wetness period

Average temperature during wetness event

Strawberry Advisory System as a

tool in AgroClimatehttp://agroclimate.org/tools/strawberry/

Strawberry Advisory System

Strawberry Advisory System

Weather data

Disease simulation

Spray recommendation

Email and SMS alerts

Strawberry AlertFloral City…….Botrytis: ModAnthrac: Mod

Grower trials

2 treatments:

Fungicide applications based on:

1) Grower standard

2) SAS recommendations

Data collection:

60 to 200 plants per treatment

1) Disease incidence (AFR and BFR)

2) Yield

1 2

5 to 15 acres

Strawberry Advisory System2010-11

Treatment Cultivar # Sprays BFR (%) AFR (%)

Farm 1

Grower Festival 16 5.0 a 2.2 a

SAS Festival 8 3.9 a 0.2 b

Farm 2

Grower Festival 18 3.5 a 2.2 a

SAS Festival 8 2.0 a 0.1 b

Farm 3

Grower Festival 12 1.7 a 0.8 a

SAS Festival 8 1.3 a 0.5 a

Farm 4

Grower Festival 18 2.2 a 0

SAS Festival 10 0.9 a 0

Strawberry Advisory System2011-12

Treatment Cultivar # sprays BFR (%) AFR (%)

Dover 1

SAS Alafia 11 2.3 a 0 a

Grower Alafia 13 2.7 a 0 a

Dover 2

SAS Radiance 11 32.5 a 0.1 a

Grower Radiance 13 28.2 a 0.1 a

Plant City

SAS Radiance 8 17.9 a 0.6 a

Grower Radiance 13 18.0 a 0.6 a

Floral City

SAS Festival 12 0.8 a 0.3 a

Grower Festival 17 0.9 a 0 a

Strawberry Advisory System2012-13

Treatment Cultivar # sprays BFR (%) AFR (%)

Dover

SAS Alafia 10 3.6 a 0.2

Grower Alafia 16 7.0 a 0.3

Plant City 1

SAS Radiance 7 3.9 a 0.3

Grower Radiance 15 2.0 a 0.5

Plant City 2

SAS Festival 7 4.5 a 0.2

Grower Festival 15 4.9 a 0

Floral City

SAS Festival 24 2.7 a 0

Grower Festival 15 3.4 a 0

Strawberry Advisory System2013-14

Treatment Cultivar # sprays BFR (%) AFR (%)

Plant City 1

SAS Radiance 11 2.1 a 0.5

Grower Radiance 16 4.4 a 0.5

Plant City 2

SAS Radiance 11 4.7 a 0.6

Grower Radiance 16 5.9 a 0.4

Floral City 1

SAS Winter Star 13 1.4 a 0

Grower Winter Star 18 0.5 a 0

Floral City 2

SAS Festival 13 1.6 a 0

Grower Festival 18 1.0 a 0

Summary

SAS can help FL growers reduce the number of fungicide applications for control of AFR and BFR without reducing disease control or yield

Recent survey has shown that around 50% of acreage is using SAS recommendations to manage AFR and BFR (success reasons)

USDA-SCRI project funded to validate and expand the system to North Carolina, South Carolina, Ohio and Iowa, California, New York, Virginia, Georgia… (challenges)

Botrytis outbreak in 2012

Evaluation of fungicide sensitivity in Botrytis from FL

12 locations surveyed Number of isolates = 470

n Number of isolates/field

Distribution of resistance to Pristine/Cabrio

HiPk

Ci

Sensitive

Resistant

Distribution of resistance to Scala/Cyprodinil

HiPk

Ci

Sensitive

Resistant

Distribution of resistance to Elevate

HiPk

Ci

Sensitive

Resistant

Distribution of resistance to Switch

HiPk

Ci

Sensitive

Resistant

Evaluation of fungicide sensitivity in Botrytis from FL

13.5

86.5

Pristine (boscalid)

40.5

59.5

Scala (pyrimetanil)

60

40

Elevate (fenhexamid)

5

95Topsin-M (thiophanatemethyl)

Sensitive Resistant

14.6

85.4Pristine (pyraclostrobin)

47.3

52.7

Switch (cyprodinil)

100

Switch (fludioxonil)

7

11

1

9

9

17

Multiple fungicide resistance in Florida

S Sensitive

FR1 Resistant to 1 fungicide

MR2 Resistant to 2 fungicdes

MR3 Resistant to 3 fungicdes

MR4 Resistant to 4 fungicdes

n = 19n = 50

n = 80

n = 29

n = 29

n = 70

n = 34

n = 60n = 57

Current recommendations

Apply only when conditions are conducive for BFR

development

Moderately favorable conditions

Thiram or Captan +

Elevate, Fontelis or (Merivon)*

Highly conducive

Switch

GCREC Strawberry Pathology