INTEGRATED MANAGEMENT OF POWDERY AND DOWNY … · INTEGRATED MANAGEMENT OF POWDERY AND DOWNY...

Department of Employment, Economic Development and Innovation

Elio JovicichChrys Akem Gerry MacManus

Downy mildew Powdery mildew

INTEGRATED MANAGEMENT OF POWDERY AND DOWNY MILDEWS IN ZUCCHINI

INTEGRATED MANAGEMENT OF POWDERY AND DOWNY MILDEWS IN ZUCCHINI

Agri-Science Queensland, DEEDI, Ayr, Queensland, Australia

2© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Downy mildewPseudoperonospora cubensis

Powdery mildewPodosphaera xanthii

Issues with disease spread and control• Sequential plantings• Proximity between crops; different growth stages• Infected crops sometimes abandoned• Carryover inoculum becomes exposed to multiple

sprays of the same active ingredient• Overuse of systemic fungicides favour the survival

and proliferation of resistant pathogen strains• Disease control sometimes ineffective

Foliar diseases in zucchini in North Queensland, Australia

• Queensland grows 73% of a total area (2,219 ha) with zucchini & squash in Australia

• In North Qld., field crops grow from March-November• Warm and dry; light morning dews; few rain events

Dry Tropics


Poster # 1

• To screen cultivars for low reaction to foliar diseases

• To measure efficacy of spray products alternative to conventional systemic and contact fungicides

Oral Session 9Thursday 10:45

Improving disease control through integrated managementImproving disease control through integrated management

• To identify programs that reduce the use of conventional systemic and contact fungicides by including alternative spray products and cultivars with disease resistance

Oral Session 5Tuesday 16:15

• To monitor and detect loss of sensitivity or resistance of powdery mildew strains to systemic fungicides

Poster # 41

Objectives of this and related research presented in this symposium


Reactions of zucchini cultivars to powdery mildew and downy mildew in field trials conducted at Bowen and Ayr in 2008

PaydirtCrowbarCLX29881

582-6 Caroline

CalidaAmanda

Zest

HMX5702

7708Congo

Houdini

Golden Rod

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10

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30

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60

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90

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0 10 20 30 40 50 60 70 80 90 100

Rel

ativ

e se

verit

y of

PO

WD

ERY

MIL

DEW

(Bow

en –

Pla

ntin

g 19

Jun

e)

Relative severity of DOWNY MILDEW(Ayr – Planting 29 April)

Nodisease

Nitro


Relative effectiveness of alternative spray products for management of foliar diseases in zucchini. North Queensland field trials.

Spray product Downy PowderyBion ●●● * ●● *Microthiol ●●● ●●●Tricop ●● ●●●Trilogy ● ●●AgriFos 600 ●●● ●●milk ● ●●Synertrol Horti Oil ● ●●Timorex ● ●●Enhance KCS ● ●●Stand SKH ● ●●Peratec ● ●CalAgri 50NF ● * ●● *Ecocarb ● ●●

Relative disease suppression to conventional fungicides and unsprayed controls.Weekly sprays at runoff volumes

●●● Good to medium ●● Medium to low ● Low to none * Some phytotoxicity

or yield reduction observed


Main constituent ingredients and commercial products used in spray programs

Commercial product Acronym Active ingredient Formulation Distribution in AU Alternative

Agri-Fos 600® AF Phosphorus acid 600 g/L Agrichem Bion® (= Actigard 50WG®) BN Acibenzolar-s-methyl 500 g/L (= 500 g/kg) Syngenta Crop Protection Tricop® TP Copper octanoate 18 g/L Colin Campbell Chemicals

Conventional

Acrobat SC® + Mancozeb AMZ Dimethomorph + Mancozeb 500 g/L + 750 g/kg BASF Australia Farmoz Amistar 250 SC® AR Azoxystrobin 250 g/L Syngenta Crop Protection Mancozeb 750® MZ Mancozeb 750 g/kg Farmoz Nimrod® ND Bupirimate 250 g/L Farmoz Bravo® BV Chlorotalonil 720 g/L Syngenta Crop Protection

Different sulphur formulation

Microthiol Disperss® MD Micronized sulphur 800 g/kg Nufarm


• Selected zucchini cultivars with different reactions to foliar diseases Relative resistance to the diseaseCultivar Seed company Powdery mildew Downy mildewHoudini Syngenta Low Low Calida Clause Medium Medium to Low Nitro SPS High Medium Paydirt Syngenta High Medium

• Selected foliar disease spray programs used on zucchini cultivars

TreatmentsTreatments

Weeks from planting 1 2 3 4 5 6 7 8 Spray dates First crop planted 2 June 2010 10 June 17 June 24 June 1 July 7 July 14 July 21 July 28 July Second crop planted 3 Aug 2010 13 Aug 19 Aug 26 Aug 2 Sep 9 Sep 16 Sep 23 Sep --

Spray program a) BN-BN-BN-TP-MD-TP-MD-TP Bion Bion Bion Tricop M.Sulf. Tricop M.Sulf Tricop b) AF-AF-AF-TP-MD-TP-MD-TP AgriFos AgriFos AgriFos Tricop M.Sulf Tricop M.Sulf Tricop c) AF-AF-AMZ-TP-MD-TP-MD-TP AgriFos AgriFos Acro+MZ Tricop M.Sulf Tricop M.Sulf Tricop d) AMZ-AR-MZ-ND-BV-MD-BV-MD Acro+MZ Amistar Mancozeb Nimrod Bravo M.Sulf Bravo M.Sulf e) No spray -- -- -- -- -- -- -- --

• Four cultivars under 4 spray programs and an unsprayed control


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1-Jun 11-Jun 21-Jun 1-Jul 11-Jul 21-Jul 31-Jul 10-Aug 20-Aug 30-Aug 9-Sep 19-Sep 29-Sep

Minimum temperatureMaximum temperature

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1-Jun 11-Jun 21-Jun 1-Jul 11-Jul 21-Jul 31-Jul 10-Aug 20-Aug 30-Aug 9-Sep 19-Sep 29-Sep

Air

rela

tive

hum

idity

(%)

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20

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RainfallRelative humidity 9 am

1st Cropplanted 2 June

2nd Cropplanted

3 August

Air

rela

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idity

(%)

Air

tem

pera

ture

(ºC

)

Rai

nfal

l (m

m)

Maximum and minimum day air temperatures and air relative humidity and rainfall, in Ayr in 2010

6 mm 165 mm

Downy mildew 195 %-days 1115 %-days

Powdery mildew 115 %-days 65 %-days

Severity in unsprayed plants


Cumulative severity (AUDPC) of powdery mildew and downy mildew in 4 zucchini cultivars under 5 spray programs for foliar disease management

First planting, 2 June 2010

Calida

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Downy mildew (%-days)

Pow

dery

mild

ew

(%-d

ays)

Nitro

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-100 0 100 200 300 400 500


Pow

dery

mild

ew

(%-d

ays)

Paydirt

-100

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200

300

400

500

-100 0 100 200 300 400 500


Pow

dery

mild

ew

(%-d

ays)

Houdini

-100

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100

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300

400

500

-100 0 100 200 300 400 500


Pow

dery

mild

ew

(%-d

ays)

Pow

dery

mild

ew(%

-day

s)

Downy mildew (%-days) Downy mildew (%-days)


Pow

dery

mild

ew(%

-day

s)

Pow

dery

mild

ew(%

-day

s)Po

wde

ry m

ildew

(%-d

ays)

Spray programs only reduced powdery mildew in Houdini

95%91%

No effects from spray programs


a) BN-BN-BN-TP-MD-TP-MD-TP b) AF-AF-AF-TP-MD-TP-MD-TP c) AF-AF-AMZ-TP-MD-TP-MD-TP d) AMZ-AR-MZ-ND-BV-MD-BV-MD e) No Spray


Cumulative severity (AUDPC) of powdery mildew and downy mildew in 4 zucchini cultivars under 5 spray programs for foliar disease management

Second planting, 3 August 2010

Calida

-100

0

100

200

300

400

500

0 500 1000 1500


Pow

dery

mild

ew

(%-d

ays)

Nitro

-100

0

100

200

300

400

500

0 500 1000 1500


Pow

dery

mild

ew

(%-d

ays)

Houdini

0

100

200

300

400

500

0 500 1000 1500


Pow

dery

mild

ew

(%-d

ays)

Paydirt

-100

0

100

200

300

400

500

0 500 1000 1500


Pow

dery

mild

ew

(%-d

ays)

Pow

dery

mild

ew(%

-day

s)



Pow

dery

mild

ew(%

-day

s)

Pow

dery

mild

ew(%

-day

s)Po

wde

ry m

ildew

(%-d

ays)

28%

37%



Program with Bion decreased downy mildewseverity

Program with Bion decreased downy mildewseverity

a) BN-BN-BN-TP-MD-TP-MD-TP b) AF-AF-AF-TP-MD-TP-MD-TP c) AF-AF-AMZ-TP-MD-TP-MD-TP d) AMZ-AR-MZ-ND-BV-MD-BV-MD e) No Spray


0 5 10 15 20 25 30

Calida

Houdini

Nitro

Paydirt

Total yield (t/ha)

a

a

b

c

Fruit yield main effects for cultivars


First planting, 2 June 2010

0 5 10 15 20 25 30

Calida

Houdini

Nitro

Paydirt

Total yield (t/ha)

d

c

a

b

Under low downy mildew pressure, yields were greater in sensitive cultivars

Under high downy mildew pressure, yields were greater in cultivars withmoderate resistance


444

223

309

348

0

0 100 200 300 400 500

Cost of spray program ($/ha) [Includes spray product only]

0 5 10 15 20 25

Total yield (t/ha)

a

b

e

ab

a

a) BN-BN-BN-TP-MD-TP-MD-TP

b) AF-AF-AF-TP-MD-TP-MD-TP

c) AF-AF-AMZ-TP-MD-TP-MD-TP

d) AMZ-AR-MZ-ND-BV-MD-BV-MD

e) No Spray

Marketable fruit yield and estimated costs of spray programs



Conclusions

• Under high disease pressure, the use of both, cultivars with moderate resistance and programs with alternative fungicides, were as effective as a selected program with conventional fungicides

• Some of the tested alternative products are available and can be cost effective if used in programs with other spray products

• An area-wide plan for managing these diseases should integrate the use of crop genetic resistance to the diseases, products alternative to conventional fungicides, effective conventional fungicides, and crop hygiene practices

• Integrated programs should also prolong the life of effective systemic fungicides


Acknowledgments

Seed companiesClauseLefroy Valley Terranova SyngentaSeminisSPS

Plant Pathology teamChrys Akem Elio JovicichGerry Mac ManusKerry-lee Stockdale Dalvinder Lakhesar Paula Boccalatte

Chemical companiesColin Campbell (Chemicals) Pty LtdOrganic Crop Protectants Pty Ltd.Agrichem Mfg. Co.Jaegar Australia Pty LtdNufarmSyngenta Crop Protection Pty Cal Agri, Products LLCBayer Australia Ltd

Agri-Science Queensland,Department of Employment, Economic Development and Innovation

Horticulture Australia Limited

Project VG07127Integrated Management of Foliar Diseases in Vegetable Crops

INTEGRATED MANAGEMENT OF POWDERY AND DOWNY … · INTEGRATED MANAGEMENT OF POWDERY AND DOWNY...

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