The susceptibility of cultivated rubus varieties to Phragmidium violaceum, the cause of blackberry leaf rust, and fungicides for the control of the disease

WAr

lir ,,'

l'tl'UTE 16.

ta-ss

LIBRARY

THE SUSCEPTIBIIITY OF CUTTIVATED ^RU8US VARIETIES ^TO

PHRAGMIDT'JIT VTOLACEIJ¡'|, THE CAUSE OF BIACKBERRY IEAF RUST, AND FUNGICIDES FoR THE coNTRot oF THE ^DISEASE

by

gJilliam

5.

tlashtngton, ^B.Agr.5c1.

A

thesls

^presented

in part fulfil¡rent of the

requlrements

of

^the

degree

of l{aster of Agrlcultural

Sclence (Pest l¡ianagenent)

at the UniversitY of

Ade1aide.

DePartnent

of

Entomology'

ftaite Àgricultural

^Research

Instltute,

UniversltY of

Adelalde.

June ¹⁹⁸⁵

FIGURES TABIEs

sUMMÀRY DECTÀRATION ACKNOTTTEDGEMENTS

CHAPTER ¹ 1.1 1.2

CHAPTER 2

TÀBIE OF CONTENTS

INTRODUCTION

Phragmidium violaceum

P.

^{vioraceum as}

a biological control

^agent

OBSERVÀTIONs OF

P.

YfOtACEUH ^ON

R.

FRUTICOSUS AGG.

IN

^VICTORIA

Introduction

Materials

^{and Methods}

Results Discussion

SUSCEPTIBILITY ^TESTING

Introduction

Materials

and Methods

Results Discussion

FUNGICTDE ^EVÀTUÀTION

Effect of fungicides

on spore germination

Introduction

Materials

and Methods

Results Discussion

Page

iii

v

vi vii

VlII

I

1

5

2.1 .1

2.L.2

2.1 .3 2.1 .4

7 7 1

I

19

CHÀPTER 3

3.1 3.1 3.1 3.1

I

2 3 4

20 20 21 26 38

CHÀPTER 4

4.1

4.1 .1

4.1.2 4.1.3 4.1 .4

41 41 41 42 44 47

il

Effect of fungicides

as

protectlve

and

curative

treatnents

fntroductlon

Materials

and Methods

Results Dlscussion

CHAPTER

5

GENERAT DI5CUSSION

APPENDIX ¹ APPENDIX 2 APPENDIX ³ ÀPPENDIX 4

ÀPPENDIX 5

APPENDIX 6

RETERENCES

4.2

4.2.1 4.2.2 4.2.3 4.2.4

48 48 49 52 59

6Z

64 68 69 70 78 8Z

86

2.1

LIST OF ^FIGURES

Symptoms

of the uredinial

and

telial states

^of

P.

violaceum on leaves

of n.

^{pl^ocerus.}

Close-up

of uredinia

and

telia of p.

^vioraceum.

Syutpto¡ts

of the

spernagonial

state of p.

^vioraceum

on l"eaves

of n.

^procerus.

2.2 2.3

2.4

^Symptoms

of the aecial state of p.

^{violaceum on}

leaves

of R.

^procerus.

2.5

Photomlcrographs

of the telial state of p.

^vioJaceum

on leaves

of n.

^procerus.

2.6

Photomlcrographs

of the basidial

and spermagonial states

of p.

vioraceum on leaves

of R.

^procerus.

2.7

Photornicrographs

of the

spernagonial ^and

aecial states of P.

violaceum on leaves

of n.

^procerus.

2.8

Photomicrographs

of the uredinial state

^of.

p.

_violaceun

on leaves

of n.

^procerus.

3.1

Developnent

of p.

^vioraceum

in host

and non-host

varietles of

Rubus 12 days

after inoculation.

3.2

^Results

of

^two

susceptlbllity tests,

^{showing synptom}

expression on detached

leaflets of

^Rubus

varieties

1Z days

after lnoculation with p.

_vioraceum.

3.3

^Symptom expression on detached

leaflets of

^raspberry

(lnnune) 15 days

after lnoculation with p.

vioraceun'

3.4

^Synpton expression on detached

teaflets of Olallie (hlghly reslstant)

^{15 days}

after inocu}ation with P.

violaceum.

3.5

^Symptom expression on detached

leaflets of

^Conanche

(resistant)

15 days

after inoculatlon with p.

_violaceun.

3.6

^Symptom expression on detached

leaflets of Silvan (slightly susceptible)

15 days

after inoculation with p.

_violaceun.

3.7

^Symptorn expresslon on detached

leaflets of

^Dirksen

Thornless (noderately

susceptibte)

^{15 days}

after inoculation with P.

vioJ.aceum.

3.8

^Symptom expression on detached

leaflets of R.

^procerus

tniôntv susceptible)

^{15 days}

after inoculation with P.

^violaceum.

4.1 Probit regression l-ines for fungicide spore gerninatlon tests.

Page

4.2 Problt regression lines for funglcide protective tests.

4.3 Problt regresslon llnes for fungicide curative tests,

4.4 Effect of protective funglcide treatnents, applied 24

hours

before inoculatlon of p.

violaceum onto detached

}eaflets of n. procerus,

^{15 days}

after

inoculatfon.

4.5 Effect of curative fungiclde treatments, applied 4 days

after lnoculatlon of p.

^violaceum

onto

^detached

Ieaftets of R. procerus,

^{15 days}

after lnoculation.

iv

Page

53 55

57

58

LIST OF ^TABLES

2.1

Characters which

distinguish three

connon

fungal leaf

pathogens from

p.

violaceurn on

R. fruticosus

^agg.

3.1 Cultivated

Ruþus

varieties tested for susceptibility to P.

vioraceun,

their origin

^and

the area cultivated in Victoria.

3.2

Scale

for recordlng the

degree

of infection,

^and

infection

categories of p.

violaceum on detached leaves

of

Ruþus

varieties.

3.3 Susceptibitity of cultivated

Ru¡us

varieties to P,

violaceum.

4.1

Concentrations

of fungicides

^which

inhibited

^{50e" and 90e.}

of

urediniospore germination

of p.

^vioraceum.

4.2

Concentrations

of fungicides

whÍch

inhibited

^{50e. and 90e"}

of uredinia of p.

violaceum when appLied as

protective treatnents.

4.3

Concentrations

of fungicides

^which

inhibited

^{502" and 90e"}

of uredinia of p.

^{vioraceun when}

applied as curative

treatments.

Page

22

34

36

45

51 9

54

v1

SUMMÀRY

Cultivated

^Ruþus

varieties

were compared

wlth n.

^procerus

for their susceptibility to P.

vioraceum,

a

^pathogen

flrst

^recorded

in Victoria in

February

1984. Susceptibitity

^{was assessed}

by the inoculation of

detached leaves

in the laboratory.

QbservatÍons were ^made on

both

^the microscopic and macroscoplc development

of the rust. These studies

showed

that

Thornless Evergreen ^was

highly susceptible;

^Thornfree'

Dirksen ThornLess and Snoothstem were moderately

susceptible;

^{and Silvan}

and Lawtonberry were

slightly susceptlble. the

pathogen reproduced on

alI

^these

varleties.

^{Cherokee, Cheyenne, Comanche} and Marionberry ^vrere

resistant to the rust, while

Youngberry, Boysenberry and

Olallle

^were

highly resistant.

L,oganberry and raspberry t{ere ^imnune.

Fungicides vfere evaluated

for thelr effect

^on

P.

^violaceum'

Àctivity against

^spore germtnation

in vitro decreased in the order:

nancozeb

) triforine ) flutriafol )

copper

hydroxide ) trladinefon

⁾ propiconazole

)

RH

3866.

Tests on detached leAVeS

Of R.

^{procerus showed}

that t¡e protective activity of the fungicides

^decreased

in the

^order:

nancozeb, propiconazole, RH 3866,

triforine ) triadímefon ) copper

hydroxide. Curative activity, also tested

^{on detached}

leaves'

^decreased

in the order: flutriafol, propiconazole,

RH

3865' triadimefon

⁾

Lriforine )) copper hydroxide, nancozeb. Phytotoxicity was observed at high concentrations wlth triadi¡refon and propiconazole, and to a lesser

extent with

RH 3866 and copper hydroxide'

Qbservations

of natural infection on R.

^procerus

in the field

showed

that aII

^stages

in the life-cycle of p.

violaceum which occur

in

Europe

are

forned ^under

Australian conditions.

Spermagonia and aecidia were observed

in

september;

uredinia

from ^October

until

^May;

telia in

small but lncreasing

^nunbers

fron

^Dece¡nber

until

Septenber; and basidia

in

^September.

DECTARATION

The work descrlbed

in this thesis is entirely

^{my own} and has not been

previously published,

unless otherwise

stated, or subnitted to

^any

unlversity for the

^award

of a

^degree

or

^diploma'

f

^consent

to the thesis

^{belng ¡nade}

available for

photocopying and

Ioan.

June 1985

tI.S.

I{ashlngton'

PLant Research

fnstitute,

Burn1ey.

ü

',t'ù

vrI]-

ACKNOWLEDGEMENTS

This investÍgation

^was

carried out at the Plant

^Research

Institute of the Victorian

Department

of Agriculture.

^During

the

^course

of

the

investigation, the

assistance

of

^many people was received.

In particular I would like to thank my supervisor Dr. D.A. Èlaelzer

of the tlaite Àgricultural

^Research

fnstitute for his

^{guidance and}

constructive criticisrn (in absentia!). Similarly I would like to thank

Dr.

P.R. Merriman

of the

PLant Research

Institute for his helpful

suggestions

especiatly during the preparation of the thesis.

^Thanks

also

^go

to Mr. E.

Bruzzese

of the Keith Turnbull

^Research

fnstitute

^who,

partlcularly in the early

^stages

of the investigation,

^{gave invaluable} advice on

the

methodology associated

with

^{many aspects}

of the

work.

Sincere thanks ^go

to Mrs.

^Maree

Martin,

and Monsieur

B. Luttun

^(a

visiting student

from ENITH, Angers, France)

for their

^technical

assistance

during part of the investigation; to Mr. P.

^Franz

for

assistance

with

experimental design and

statistical

^analysis;

to Mr. P.

Firman

for

sone

of the

photographic

work; to Mr.

M.

Perry for

exuberant assistance

with the

^FÀCQM

computer; to Mrs. A.

Stephenson of

Jentra

Secretaria1

for

word

processing; to ny

colleagues

at the

Plant Research

Institute,

and

in particular to Mr. I.G.

Pascoe

for his quiet

enthusiasn

for all things nycological. f also

thank

Mr.

Pascoe

for providing the

photograph

that

appears

as Figure

^2.6A.

Thanks

are also

due

to lrlr. tt. Knoll,

and

Mr. À. Pitt for the

supply

of cultivated

^puous

plants;

and

to

Bayer

Aust. Pty. Ltd.,

Ciba-Geigy

Àust. Pty. Ltd., I.C.L Àust.

Operations

Pty. Ltd.,

^{Rohn and Haas Aust.}

Pty. ttd. and Shelt Chenicals Aust. Pty. ttd. for the suppLy of the

fungicides

used

in

these studies.

To my

family: f extend deep thanks to my parents for their

encouragement, and especiaLly

to

ny

wife

Bindy

for her interest, practical

assistance and

patient

understanding.

"Give thanks

to the Lord,

^{because he}

is

^good;

eternaJ.. ^"

i.

!

PsaIm 136:1.

his

Love

is