Strawberry Update 2011

8/9/2019 Strawberry Update 2011

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Strawberry R&Dupdate

Welcome to the 2011 edition of the Strawberry R&D Update, bringing

you the latest results of research and development from the strawberryteam in the Department of Employment, Economic Development and

Innovation in Queensland. Topics covered in this edition include:

Plant breeding . . . 2

Key attributes of the new cultivars Aussiegem and Suncoast

Delight

What progress is being made in developing cultivars that are

resistant to plant diseases?

Transplant agronomy . . . 5 What was the quality of Festival and Florida Fortuna plants

supplied to Sunshine Coast growers for the 2011 season?

What are the optimum planting systems for Florida Fortuna

on the Sunshine Coast?

Entomology . . . 10

What is the nature of the insect vector responsible for

introducing the strawberry lethal yellows disease organisms

into healthy plants?

What strategies can be used to limit the impact of lethal

yellows in commercial strawberry plantings?

Plant pathology . . . 15

Are the different isolates of the crown rot fungi resistant to

prochloraz, the main chemical used to control the disease in

the plant nurseries?

Do the different isolates of the crown rot fungi cause disease

in healthy strawberry plants?

What are the best options for the control of the bud and leafnematode?

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2 Strawberry R&D Update 2011

Plant breedingMark Herrington, Louella Woolcock, Sam Price, Michelle Paynter and

Lien Ko

Overview

The main objective of our research is to breed new cultivars that

consumers enjoy and that are profitable for commercial strawberry

growers in south-east Queensland. This industry is primarily based on the

Sunshine Coast with an annual production of about 27,000 tonnes, worth

$140 million. Production in this region accounts for about half of the

national strawberry crop.

For consumers, qualities sought in new cultivars include flavour,

sweetness, and a long shelf-life. Growers are interested in these

attributes, along with productivity, earliness, and the ease of growing,

harvesting and marketing of the crop. The characteristics used toevaluate new cultivars are developed in collaboration with members

of the National Strawberry Varietal Improvement Steering Committee

(NSVISC), which meets twice a year.

Evaluation of new cultivars by commercial growers

In 2011, Plant Breeders Rights (PBRs) applications were finalised for

Aussiegem and Suncoast Delight. Transplants of these new cultivars

are now available from the strawberry nursery industry.

These cultivars continue to show promise

in commercial evaluations and are highly

productive and well liked by consumers.

Because of their large fruit and continuous

cropping, these cultivars have relatively low

harvesting costs compared with standard

cultivars. Aussiegem has large, juicy fruit,

and medium to low acidity; however, the

fruit are moderately susceptible to rain

damage. Suncoast Delight has highly

coloured, juicy, flavoursome fruit. The only

issue with quality in this cultivar is that

some fruit may have white shoulders duringcool weather.

Florida Fortuna, introduced from the United

States under a separate program with Dr

Craig Chandler, also continues to show

promise in many areas of the Sunshine

Coast, although it is moderately susceptible

to grey mould.

Three other selections from 2007 to 2009

have merit and have been advanced for

small-scale testing on commercial propertiesin 2012.

Grant Bignell checking the quality of someof the new breeding lines.

Mary and Tali Grace sorting berriesharvested from the breeding plots.


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Strawberry R&D Update 2011 3

Early generation selections

About fourteen-thousand seedlings

were evaluated for fruit quality,

productivity and plant type in the

field at Maroochy and Bundaberg

Research Stations in 2011. The site

at Bundaberg is warmer than the

one at Maroochy, and is providing

an opportunity to select cultivars

with some heat tolerance.

At the end of the season, 246

selections were made for further

evaluation. About 10,000 new

seedlings are due to be planted in

2012.

Collaboration with Florida

Mark Herrington attended the North American Strawberry Symposium

(NASS) and the North American Strawberry Growers Association

(NASGA) Conference at the University of Florida in February 2011. Areas

of interest included strengthening the links between the two subtropical

breeding programs at Maroochy and Wimauma.

Mark was particularly interested in exchanging germplasm between the

two programs. He also took the opportunity to discuss techniques used

for the screening of selections for resistance to grey mould.

The resistance or tolerance of strawberry cultivars to plantdiseases

As we progress towards selecting for resistance to Fusarium wilt caused

by the fungus, Fusarium oxysporum, we re-evaluated the diversity of

the pathogen and the resistance of cultivars to isolates of the fungus

collected from strawberry plants growing in Queensland and Western

Australia. The four isolates collected from Western Australia were

homogeneous and distinct from the different isolates collected from

Queensland.

We plan to look more closely at the

variability of the pathogen to ensure

that any cultivars that are developed

will be resistant to isolates from

both regions.

We have continued our work to

select for resistance to crown rot.

Research has shown that Glomerella

cingulata(Gc2) is the dominant

form of the fungus in southern

Queensland, and in 2011 we used

isolate 17360 of this fungus to testseedlings of a wild strawberry, and

Plants in the glasshouse used for cross-pollination.

Lou Woolcock weighing fruit from the breeding plots.


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Sam Price writing a report on the breeding program.

Florida Elyana (all from the United States) for resistance. These tests

showed that one of the seedling plants had some tolerance to the disease,

while the accession of Florida Elyana was as susceptible as Camarosa

and Festival. These responses require further investigation.

Mark Herrington analysing some of the data from the breeding project.

Michelle Paynter isolating specimens of Fusarium.


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Transplant agronomyChris Menzel and Lindsay Smith

Overview

Research has shown that the quality of planting material has astrong effect on the profitability of strawberry growing in south-east

Queensland. Inferior transplants grow and crop poorly after planting,

reducing monetary returns to producers. These issues also affect growers

in the southern parts of Australia.

In earlier experiments on the Sunshine Coast, we examined the effect of

planting systems on the performance of bare-rooted Festival strawberry

plants at Nambour. Yields were best with a planting in mid-March, with

lower yields resulting from earlier or later plantings. Plants obtained

from Stanthorpe in southern Queensland, a warm-growing environment,

were just as productive as those from Toolangi in Victoria, or fromKempton in Tasmania, two cool-growing environments. In contrast, large

plants from these nurseries with crown diameters ranging from 10 to 17

mm had seventeen percent higher yields than small plants with crown

diameters ranging from 6 to 10 mm.

We have continued this work and have examined the optimum planting

systems for Florida Fortuna, a new cultivar introduced from the United

States. Research assessed the effect of time of planting and plant size

on the productivity of this cultivar growing in small plots at Nambour.

The experiments differed from previous research in that the treatments

assessed small and large transplants planted at different times. We were

interested in determining if the small transplants yielded proportionally

less than the large transplants as planting was delayed.

In other research, the quality of transplants from strawberry nurseries

in southern Queensland was assessed. Samples were collected from

Healthy nursery transplants growing at Stanthorpe.


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consignments of Festival and Florida Fortuna, the two dominant

cultivars grown on the Sunshine Coast. Plant attributes recorded

included the diameter of the plant crown, the number of leaves per plant,

and plant dry weight.

Optimum planting systems for Florida Fortuna transplants on the

Sunshine Coast

Bare-rooted transplants of Festival and Florida Fortuna obtained from

Stanthorpe were planted at different times from late March to early May

at Nambour. We used only sound, undamaged plants with at least three

functional leaves. The Festival plants were classified as small plants

with crowns smaller than 10 mm in diameter, and large plants with

crowns larger than 10 mm in diameter. The Florida Fortuna plants were

classified as small plants

with crowns smaller than 8

mm in diameter, and large

plants with crowns largerthan 8 mm in diameter.

The plants for each

treatment were grown in

four replicated blocks.

Information was collected

on plant growth and yield

over the season from May

to October. The experiments

were conducted over two

years.There was no consistent

effect of time of digging on initial transplant quality, whereas the large

transplants were about three times the size of the small transplants (see

Tables 1 and 2).

Average plant growth during the season decreased as planting was

delayed, and was lower in the small stock compared with the large stock.

Yield in the various treatments reflected these differences in growth.

Yield was lower in the later planting, and was lower in the small plants

than in the large plants (see Tables 1 and 2).

Table 1. The effect of time of planting and plant size on plant dry weight and yield

of bare-rooted Festival strawberry plants at Nambour. Data are the means over

two years. Plant dry weight includes the mass of the leaves, crowns and roots.

Planting system Plant dryweight at

planting (g)

Average plant dryweight duringthe season (g)

Yield(g per plant)

Planted in late March 4.0 22.1 921

Planted in mid-April 4.0 15.1 679

Planted in late April 4.1 13.7 692

Small plant 1.9 13.6 694

Large plant 6.2 20.2 834

A crop of Festival fruit. Planting systems have been developed for the production ofthis cultivar on the Sunshine Coast.


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Table 2. The effect of time of planting and plant size on plant dry weight and

yield of bare-rooted Florida Fortuna strawberry plants at Nambour. Data are the

means over two years. Plant dry weight includes the mass of the leaves, crowns

and roots.

Planting system Plant dry

weight atplanting (g)

Average plant dry

weight during theseason (g)

Yield

(g per plant)

Planted in early April 2.9 12.7 825

Planted in mid-April 2.7 11.2 634

Planted in early May 3.0 8.8 561

Small plant 1.5 9.0 628

Large plant 4.4 12.8 718

Average yields of Festival were about fifteen percent higher than those

of Florida Fortuna, reflecting the larger plants at planting, and the

better growth during the growing season.

Average gross income was $4.68 per plant for large transplants planted

early, and $2.76 per plant for small transplants planted late. This analysis

was based on an average price received for the fruit during the season of

$1.25 per punnet.

Florida Fortuna known as Florida Radiance in the United States, was

developed by Craig Chandler. This cultivar has been reported to produce

high early-season yields and maintain good fruit size in Florida and

south-west Spain. Festival was also bred by Dr Chandler. In Australia,

transplants of Florida Fortuna are smaller than those of Festival, and

they are not available from the commercial nurseries until early April.

The previous study indicated that the optimum time to plant Festival

in south-east Queensland was in mid-March. However, because of the

difficulty of obtaining large numbers of transplants for commercial

fruit growers, stock of Festival is generally not available until after the

optimum time of planting, with the first sets of plants being consigned in

late March.

Frost during winter atMaroochy in 2011. Growingconditions were much coolerand drier in 2011 than in 2010.This provided good conditions

for fruit quality despite thesmaller plant growth.


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Transplants of Festival and Florida Fortuna had lower yields when

they were planted after late March or early April on the Sunshine Coast,

suggesting that they should be planted when they first become available

to commercial producers, although that may be later than optimum.

Differences in yield between small and large plants were consistent

across different times of planting, with the small plants always havinglower yields. Producers in this area should consider paying a premium

for large transplants delivered early in the season.

The variation in the quality of transplants from individualstrawberry nurseries

We report on the variation in the quality of transplants from southern

Queensland in 2011. Plant samples of the two main cultivars, Festival

and Florida Fortuna, were collected over three digging dates from late

March to early May. Plants of Florida Fortuna were included in the

study since there is interest by local growers in this new cultivar from

the United States.

As in previous years, consignments of plants were obtained from

nurseries at Stanthorpe, and information was collected on the diameter

of the crown, the number of leaves per plant, and on plant dry weight.

The Festival plants were larger than the Florida Fortuna plants on all

digging dates (see Tables 3 and 4). For instance, the average dry weight

of the Festival plants was about twice the average dry weight of the

Florida Fortuna plants. This was due to the larger leaf, crown and root

masses of the Festival plants.

Table 3. A comparison of mean transplant quality in Festival strawberry

plants obtained from Stanthorpe at different times of digging in 2011. Data in

parenthesis show the ranges in crown diameter, leaf production and plant dry

weight. Plant dry weight includes the mass of the leaves, crowns and roots.

Time ofdigging

Diameter of thecrown (mm)

Number of leavesper plant

Plant dryweight (g)

Late March 10.2 (6-16) 3.6 (2-6) 4.0 (0.8-9.7)

Mid-April 10.1 (6-16) 4.8 (3-9) 3.9 (1.1-11.4)

Late April 10.7 (6-16) 3.9 (2-8) 3.5 (1.0-9.1)

Plant growth inthe transplantexperiment withFestival. Thephotograph showsthe growth of plantsplanted in lateMarch (left), mid-

April (middle) and inlate April (right).


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In both cultivars, there was no clear effect of digging date on plant

development, with similar mean crown diameters, leaf production and

plant dry weights in the stock dug at different times (see Tables 3 and 4).

There was a large variation in the quality of the plants from the same

nursery. For instance, the dry weight of some of the smaller plants was

less than twenty percent of the dry weight of the larger plants. The samewas true for the data collected from 2007 to 2010. The Florida Fortuna

plants were particularly variable, with many small specimens in the

consignments.

Nearly all of the Festival transplants met the minimum standard

relating to the diameter of the crown and the number of functional

leaves. In contrast, there were several Florida Fortuna transplants in the

consignments that did not meet the minimum standard.

Table 4. A comparison of mean transplant quality in Florida Fortuna strawberry

plants obtained from Stanthorpe at different times of digging in 2011. Data in

parenthesis show the ranges in crown diameter, leaf production and plant dry

weight. Plant dry weight includes the mass of the leaves, crowns and roots.

Time ofdigging

Diameter of thecrown (mm)

Number ofleaves per

plant

Plant dryweight (g)

Early April 8.5 (5-14) 3.7 (2-5) 2.2 (0.7-4.9)

Late April 8.3 (5-12) 3.3 (2-5) 2.0 (0.7-4.9)

Early May 8.8 (6-13) 3.4 (2-5) 2.0 (1.0-4.4)

About eighteen percent of the Festival transplants had crowns smaller

than 8 mm, and about forty percent had crowns smaller than 10 mm.

A similar analysis of the Florida Fortuna plants showed that about

twenty-eight percent of the transplants had crowns smaller than 8 mm,

and about sixty-eight percent had crowns smaller than 10 mm. At this

stage, the reason for the small size of the Florida Fortuna plants is

unknown. It would be expected that the small size of some of the plants

would affect their productivity on the Sunshine Coast as there is a

strong relationship between yield and plant growth in strawberry plants

growing in this area.

Plant growth inthe transplantexperiment withFestival. Thephotograph showsthe growth of small

plants (left) andlarge plants (right).


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Controlling strawberry lethal yellowsJonathan Smith, Don Hutton, Matthew Neave and Karen Gibb

Overview

Lethal yellows diseases associated with a phytoplasma and a rickettsia-likebacterium have affected strawberry plants growing in southern Queensland

since the 1970s. In strawberry plants, these organisms, which reside in

the plant phloem, cause the stunting and yellowing disease known as

strawberry lethal yellows (SLY). This type of disease is spread by insect

vectors such as plant- and leaf-hoppers.

Knowledge of the identity and ecology of the vectors of SLY is critical in

efforts to reduce transmission of the disease and the production of healthy

nursery transplants. It is also important to determine what insecticides

might be effective in managing the populations of the vectors. We provide

a review of activities conducted over the past few years on the Granite Beltand the Sunshine Coast to improve our understanding of this disease and

to develop better control strategies for the commercial strawberry industry.

The prime vector of the disease is thought to be the leafhopper,

Austroagallia torrida. This hopper was first suspected as a potential

vector in 2002 by Geoff Waite and is known to be the vector of the

rickettsia-associated rugose leaf curl disease of legumes, and the tomato

big-bud phytoplasma. We describe research to determine whether the

suspect leafhopper was infected with the phytoplasma and a rickettsia-

like bacterium thought to be associated with lethal yellows. The suspect

leafhoppers were collected from strawberry and other plants in southern

Queensland, and samples sent to Darwin for analysis to detect if potential

disease organisms were present in the insects.

As the hoppers were suspected to be feeding and breeding in weeds

and other plants growing adjacent to the strawberry planting, seasonal

populations of leafhoppers were monitored in lucerne growing next

to the strawberry

plants at Stanthorpe.

Similar information

was collected on the

populations of hoppers

in unsprayed plots ofstrawberry plants on

one of the strawberry

nurseries on the

Granite Belt.

Separate laboratory

studies were conducted

to determine if the

suspect leafhoppers

could infect healthy

strawberry plants withthe disease.Strawberry plants growing on the Sunshine Coast affected by lethal yellows.


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We also investigated the effectiveness of the current insecticide used to

control the insect vectors on the nursery farms. Data were collected on the

incidence of the disease on sprayed and unsprayed plots over three seasons

on the Granite Belt.

Identication of the suspect leafhopper

Vacuum samples of leafhoppers were taken over five months from

strawberry and clover plants growing on two nurseries on the Granite Belt

in 2008/09 and 2009/10. In the second year, lucerne plants at Stanthorpe

and Gatton were also sampled. Leafhoppers were sorted and dried prior to

their being subjected to polymerase chain reaction (PCR)-based diagnostics

for the detection of phytoplasmas and rickettsia-like bacteria at Charles

Darwin University.

No phytoplasmas were detected in any leafhopper species by the general

phytoplasma or specific CandidatusPhytoplasma australiense SLY tests.

The laboratory analysis indicated the presence of the rickettsia-like

bacterium innine out of the ten samples ofAustroagallia torridacollected

from strawberry plants, four out of four samples collected from lucerne

plants, and three out of three samples collected from clover plants.

One sample of juveniles reared in culture from adults collected from

the aforementioned lucerne was also tested. These juveniles, which had

no direct prior exposure to SLY, returned positive for the rickettsia-like

bacterium suggesting there is adult-to-juvenile transmission of the

pathogen. The analysis suggested that the rickettsia-like bacterium

found in the samples was the same in all the samples of the hopper, and

similar to the SLY rickettsia-like bacterium identified from the strawberry

reference sample.

These results are highly significant since they show that a leafhopper that

is common and abundant on strawberry plants and a variety of other

plant species growing on and around strawberry nursery farms in southern

Queensland during the critical SLY infection period carries the SLY

rickettsia-like bacterium.

Table 1. The numbers of the three main leafhoppers associated with lethal yellows

collected from sampling unsprayed strawberry nursery plots at Stanthorpe in 2009.

Data are the average number of insects collected on each sampling date.

Date ofsampling

Austroagalliatorrida

Orosiusorientalis

Anzyginaspecies

7 January 22 4 58

21 January 45 13 244

4 February 21 20 212

17 February 5 0 110

3 March 3 0 21

17 March 14 1 74

31 March 1 9 243

15 April 2 0 143

Average 14 6 138


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Populations of the leafhoppers in the nurseries at Stanthorpe

In 2009, we collected samples of leafhoppers from unsprayed plots on

one of the nursery farms at Stanthorpe. AnAnzyginaspecies was the

most common hopper in the strawberry plants, followed byAustroagallia

torridaand Orosius orientalis(see Table 1).Anzyginawas active through-

out the season, whereas the other two species were more active early

in the season. The numbers ofA. torrida

collected from these plots were lower than

the numbers collected from lucerne plants

growing near the strawberry plants from

late September to early November in 2009.

During this period, the average number

of hoppers collected was 37 hoppers per

sample (see Table 2). These results confirm

the importance of lucerne and other

plants for the breeding and survival of thehoppers and their role in the transmission

of SLY.

Populations of leafhopper can vary quite

considerably from season to season on the

Granite Belt. In 2009, the average number

ofA. torridaper sample collected from

September to November was 37 hoppers

per sample compared with 1 hopper per

sample in 2010 (Table 2). The respective

data for O. orientaliswere 10 and 1 hoppersper sample, and forAnzyginaspecies, 104

and 5 hoppers per sample.

In the past, a low incidence

of lethal yellows has been

associated with wet conditions

over winter and spring in

southern Queensland. Above

average rainfall was recorded

for much of the area to the

west and south-west of theGranite Belt late in 2010.

Sampling for the leafhoppers

in lucerne growing in areas

south and west of Stanthorpe

indicated similar total

populations of the insects

there as those in areas around

Stanthorpe.

However, the number of

A. torridain the samples

increased the further west the

Checking strawberry nursery plants atStanthorpe for symptoms of lethal yellows.

Jonathan Smith checking plants in the nursery at Maroochy forsymptoms of lethal yellows.


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samples were collected. We suspect that the hoppers originate in areas

further south and west of Stanthorpe and migrate north-east on weather

fronts in spring and early summer each year.

Table 2. The numbers of the three main leafhoppers collected from sampling

of lucerne plants growing on the Granite Belt in 2009 and 2010. Data are the

average number of insects collected on each sampling date.

Date of sampling Austroagalliatorrida

Orosiusorientalis

Anzyginaspecies

2009

22 September 10 6 104

7 October 52 8 186

23 October 60 12 83

6 November 27 16 41

Average 37 10 104

2010

7 September 1 0 3

6 October 2 1 5

4 November 1 2 8

24 November 0 0 3

Average 1 1 5

Presence of the disease organism in different hopper populations

In 2010, samples ofAustroagallia torridawere collected from clover

and lucerne plants growing at Stanthorpe and Gatton and tested for thepresence of the disease organisms. We were interested in determining

if the disease organisms could be isolated from hoppers collected from

plants growing in other places in southern Queensland. Each sample

consisted of five adult hoppers.

The results of this experiment showed that the SLY rickettsia-like

bacterium was found in four out of four samples of the hoppers collected

from clover plants growing at Stanthorpe, four out of four samples

collected from lucerne plants growing at Stanthorpe, and four out of four

samples collected from lucerne plants growing at Gatton; none tested

positive for the SLY phytoplasma. These results suggest that populationsof this hopper inhabiting clover and lucerne are potential sources of the

disease for the infection of healthy strawberry plants.

Transmission experiments

To confirm thatAustroagallia torridais the vector of SLY, transmission

studies are required. In October 2010, three insect-proof cages were set

up in Nambour, with four strawberry plants in each. The plants were

healthy with no obvious symptoms of SLY, and specific laboratory tests

confirmed that none of the plants was carrying the phytoplasma or

rickettsia-like bacterium. The experiment included plants of Festival,

Florida Fortuna, and the experimental line 2006-215.


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Leafhoppers were introduced into each of the cages on three occasions.

The hoppers were seen to alight on the plants but did not feed.

Subsequently, none of the plants showed any symptoms of lethal yellows.

These results suggest that the hoppers do not feed readily on strawberry

plants, and probably need other food sources such as lucerne to survive.

This correlates with the incidence of SLY infection in the field, and itsrelative rarity when the total hopper population is considered. It seems

possible that infection occurs as a result of vagrant hoppers wandering

into strawberry plantings, where transmission may occur merely through

their probing of the phloem tissues without feeding.

How effective are the insecticide sprays used to manage SLY in the

nurseries?

The main strategy currently used to limit the impact of lethal yellows in

strawberry fields on the Sunshine Coast is to detect and remove infected

mother and daughter plants during the transplant-production season in

the nurseries on the Granite Belt. Dimethoate and other insecticides are

also applied to kill vectors before they feed on the strawberry plants.

We compared the incidence of SLY in conventionally managed nursery

plots at Stanthorpe with that recorded in unsprayed plots over three

seasons. In the first year, the average incidence of the disease was one

percent in the insecticide-treated areas compared with fourteen percent

in the unsprayed areas. The relative data for the second year were one

percent in the insecticide-treated areas compared with eleven percent

in the unsprayed areas. In the third year, the incidence of the disease

generally was too low to make a useful comparison between the different

treatments. Overall, this work showed that the current insecticide-based

control strategy, although not perfect, is effective in

reducing the incidence of the disorder.

Conclusions

Austroagallia torrida, a leafhopper common and

abundant on strawberry plants and a variety of

other plants at Stanthorpe, carries the rickettsia-like

bacterium associated with lethal yellows. This hopper

was mostly active in the strawberry plants on the

Granite Belt from early January to early February.Specimens of the hopper collected from lucerne plants

growing at Gatton were infected with the rickettsia,

suggesting that the organism is widely distributed.

Transmission experiments showed that the suspect

hopper does not readily feed nor breed on strawberry

plants. The current strategy of spraying the strawberry

nursery plants with dimethoate to control the hoppers

appears to be the best approach to limit the impact of

the disease on the commercial strawberry industry.

AcknowledgementsChris Freebairn contributed to some of these studies.

Native plants growing at Stanthorpe. Someof these plants have distorted growth thatis often the symptom of infection with lethalyellows-type disease organisms.


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The control of the bud and leafnematode in southern Queensland

Jenny Cobon, Wayne ONeill, Don Hutton and Apollo Gomez

Introduction

The bud and leaf nematode,Aphelenchoides fragariae, was recently

detected in strawberry crops growing in southern Queensland. It caused

major losses on several properties on the Sunshine Coast. This pest is

different to the crimp nematode,Aphelenchoides besseyi, which had

previously been found in strawberry fields in this area.

Nematodes are microscopic, unsegmented roundworms that occur

worldwide in fresh and salt water, soil, decaying organic matter, plants

and animals. They have a resistant cuticle or skin, and inhabit all types

of environments, which has enabled them to become the most abundant

multicellular species on the planet. There are about 28,000 species, with

about 16,000 of these parasitic. Nematodes that are parasitic on plants

spend much of their life cycles closely associated with their host plants.

The genusAphelenchoidesincludes some of the most common plant-

parasitic nematodes.

The bud and leaf nematode is a foliar pest that has an extensive host

range. It is widely distributed throughout temperate and tropical regions

of the world. The species is frequently encountered in horticultural crops

and causes economic losses in the foliage plant and nursery industries.

As its name suggests,A. fragariae is also a major pest of strawberry

plants around the world. This nematode should not be confused withA.

ritzemabosi,another bud and leaf nematode that occurs in strawberry

plants in Mexico, but which mainly affects chrysanthemum.

Strawberry plants can be infected by nematodes transported from a

nearby infected area by wind, flooding, mechanical means, or animals.

Nematodes are also spread by infested transplants. The source of the bud

and leaf nematode found in affected strawberry fields on the Sunshine

Coast is unknown. The pest has not been found in the plant nurseries or

on a wide range of weeds sampled on the Granite Belt.

The lifecycle of the nematodeA. fragariaeis an obligate parasite of above-ground parts of plants.

This means that the nematode requires living tissues on which to

grow, reproduce and survive. On strawberry plants, the nematode is

an ectoparasite living in the folded crown and leaf buds of the plant,

and it feeds in the folded buds. The pest is bisexual, with the lifecycle

completed in ten to eleven days at 18C; several generations are

completed each year. Developmental stages include eggs, juveniles and

adults.

The nematode cannot survive in bare soil for more than three months as

it can feed and survive only on living plant material. Local research hasshown that the nematode can survive and even multiply in plant tissue


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The tail of both sexes is an elongate-conoid ending in a simple blunt

spike.

Management and control of the nematode

The impact of the nematode on commercial strawberry production on

the Sunshine Coast can be minimised with good cultural practices.Producers should maintain strict sanitation and inspection of plant

material to minimize losses. This includes the removal and destruction

of infested plants and the use of nematode-free planting material.

Excessive humidity and splashing of water on stems and leaves and

contact between plants should be avoided. Hot water treatments to ensure

clean planting material have been recommended in many situations.

An emergency use permit for the application of liquidfenamiphos

(Nemacur) into the crown of strawberry plants has been granted for

use in nurseries in southern Queensland. This is not an option for fruit

growers on the coast as there is a six-week withholding period for the

product. Further studies are required to determine the source of thenematodes in commercial strawberry fields in southern Queensland and

their impact on production.

Further reading

Maas, J.L. (1998). Compendium of Strawberry Diseases. The American

Phytopathological Society, St. Paul, Minnesota, United States, 98 pp.

McCuiston, J. L. et. al.(2007). Conventional and PCR detection of

Aphelenchoides fragariae in diverse ornamental host plant species.

Journal of Nematology39, 343355.

Siddiqi, M.R. (1975).Aphelenchoides fragariae. CIH Descriptions of Plant-parasitic NematodesSet 5, No. 7.

Strand, L.L. (2008). Integrated Pest Management for Strawberries.

University of California Agriculture and Natural Resources

Publication, Oakland, California, United States, 176 pp.

A fern infected with thebud and leaf nematodeshowing the typical leafblotches.

A strawberry plantinfected with the bud

and leaf nematode (left)adjacent to a healthyplant (right).


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Controlling crown rot in AustraliaApollo Gomez, Don Hutton, Lindsay Smith, Teresa Seijo and Natalia Peres

Overview

Crown rot caused by Colletotrichum gloeosporioides(Cg) and relatedfungi is the main plant disease affecting strawberry fields in southern

Queensland. Visual symptoms of the disease include lesions on the petioles

and stolons, and red-brown necrotic areas in the crown. Ultimately, the

affected plants wilt and die. The pathogen is present at very low levels in

the strawberry nurseries in Brisbane and in Stanthorpe, where it causes

insignificant losses. However, there can be more serious losses of up to

thirty percent of plants in individual strawberry fields when infected

transplants are consigned to the Sunshine Coast.

It is not known why low levels of infection in the nurseries can result

in significant losses in the field on the coast. Prochloraz is routinelyapplied to the nursery beds on the Granite Belt in an attempt to limit

infection of the plants and the impact of the disease on fruit production.

Pyraclostrobin (Cabrio), and cyprodinil plus fludioxinil (Switch) are

used in a resistance management strategy with prochloraz. Pyraclostrobin

is used in the tissue-culture and foundation nurseries, while cyprodinil

and fludioxinil are used in the tissue-culture, foundation and commercial

plant nurseries.

Research conducted at the University of Florida over the past five years

has shown that there are three distinct subpopulations of the main

fungi associated with crown rot in strawberry plants in Australia. Thiswork indicated that there were two subpopulations of Colletotrichum

gloeosporioides, a heterothallic group (Cg), and a homothallic group that

should be more appropriately referred to as Glomerella cingulata(Gc2),

and a subpopulation of C. fragariae(Cf). These results were based on

the analysis of 62 isolates of the crown rot fungi collected over 20 years

from different locations around

Australia. Samples of the fungi

were collected from the leaves,

crowns and stolons of strawberry

plants, and from alternative host

plants growing near strawberryfields. In strawberry, samples were

collected from plants with and

without symptoms of crown rot.

The Gc2 (Glomerella cingulata)

genotype is the current dominant

and most important strain of the

pathogen in southern Queensland.

The Cg(Colletotrichum

gloeosporioides) strain is also

present in recent isolates, but isnot as dominant as Gc2.Apollo Gomez isolating the crown rot fungi from strawberry plants.


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The Cf (Colletotrichum

fragariae) strain

is associated with

transplants grown in

nurseries used by the

strawberry industry inthe 1990s. This strain

has not been isolated

or recovered from

strawberry plants in

southern Queensland

for more than 12 years.

We investigated

the pathogenicity

of the different

subpopulations ofthe crown rot fungi

affecting strawberry plants in southern Queensland. Spores of the fungi

were grown in culture and used to inoculate healthy strawberry plants

growing in a glasshouse. Most of the isolates came from the Glomerella

cingulata (Gc2) genotype, with some isolates of the other two groups

(Cgand Cf) also included. In the initial tests, the different isolates were

injected into the highly susceptible Camarosa to confirm that the

particular isolate was pathogenic for strawberry.

The second part of the research examined the response of different

cultivars to the isolates that proved pathogenic in the test cultivar

Camarosa. This information was used to determine the relative

susceptibility of the major cultivars to the main pathogenic

subpopulations of the fungi found in southern Queensland.

Fungi can become resistant to fungicides when they are used routinely

over successive seasons. There is a possibility that the crown rot fungi

will become resistant to prochloraz, limiting the effectiveness of this

chemical to control the disease. Thus, we examined the extent of

resistance of the crown rot fungi to prochloraz. Various isolates of the

fungi were grown in culture that incorporated different concentrations of

the fungicide. The growth of the fungi in culture was used to determine

whether an isolate has become resistant to the chemical.

Pathogenicity of different isolates of the crown rot fungi

Thirty-seven isolates of the crown rot fungi collected from strawberry

plants and alternative host plants were tested for pathogenicity on

strawberry plants in a glasshouse at Nambour. Bare-rooted transplants

of Camarosa were grown in 100-ml pots filled with peat and sand

(1:1). After four weeks, the plants were inoculated, with about 0.1 ml of

inoculum injected into the lower crown using a 1-ml syringe fitted with

a 25-gauge needle. For each test isolate, there were six inoculated plantsand six control plants. The control plants were injected with sterile water.

Don Hutton checking strawberry plants for symptoms of crown rot.


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Table 1. Summary of the pathogenicity of different isolates of the crown rot

fungi injected into healthy Camarosa strawberry plants. A suspension of fungal

spores was injected into the crowns of each plant. There were six inoculated

plants and six control plants for each test, with data collected after six weeks. An

isolate was considered pathogenic if four or more of the injected plants wilted

and died. Gc2 = Glomerella cingulata, Cg = Colletotrichum gloeosporioides, andCf= Colletotrichum fragariae. The fungi were sampled from strawberry plants

with rotting leaf blades, leaf petioles, crowns and stolons, and from strawberry

plants without any symptoms of infection (leaf petiole samples). Samples of the

fungi were also collected from alternative host plants growing next to strawberry

elds (above-ground samples).

Type of isolate or sample Number of isolatesthat were pathogenic

Glomerella cingulata(Gc2) 9 out of 16

Colletotrichum gloeosporioides(Cg) 3 out of 6

Colletotrichum fragariae (Cf) 13 out of 15

Samples from infected crowns 15 out of 17

Samples from infected leaf blades 2 out of 2

Samples from infected leaf petioles 5 out 6

Samples from infected stolons 0 out of 1

Samples from symptomless plants (petioles) 1 out of 8

Samples from alternative hosts 2 out of 3

Samples collected from 1990 to 1999 16 out of 18

Samples collected from 2000 to 2009 10 out of 19

The plants were checked weekly for symptoms of crown rot and the time

from inoculation to the first signs of collapse or wilting was recorded for

each plant. Plants that wilted were sampled to confirm the presence of

the crown rot fungi. Isolates were considered pathogenic when four or

more of the inoculated plants died from crown rot after six weeks.

Nine out of the sixteen isolates of Gc2 were pathogenic to Camarosa

(see Table 1). Thirteen out of

fifteen isolates of the Cfstrain and

three out of six isolates of the Cg

strain were also pathogenic. These

results indicated that a total of 25out of the 37 isolates were able

to cause disease when injected

into healthy Camarosa plants

growing in a glasshouse. Thus, all

three subpopulations of the crown

rot fungi are capable of causing

disease in strawberry plants.

Nearly all of the isolates taken

from samples of rotting strawberry

leaf blades, leaf petioles andcrowns were pathogenic,

Lindsay Smith and Don Hutton discussing the results of some of the glasshouseexperiments on crown rot.


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regardless of the genotype (see Table 1). There was insufficient

sampling of stolons to determine whether isolates from these tissues

were pathogenic or not. Only one isolate out of eight collected from

symptomless strawberry plants was pathogenic when injected into the

healthy Camarosa plants. Two out of the three isolates collected from

alternate host plants were pathogenic when injected into the test plants.

Most of the isolates from samples collected in the 1990s were pathogenic

when injected into healthy Camarosa strawberry plants (see Table 1).

In contrast, only about half the isolates collected later were pathogenic.

Most of the older isolates were classified as Colletotrichum fragariae.

Screening of strawberry cultivars for their susceptibility to the

different subpopulations of the crown rot fungi

Only isolates that were pathogenic when injected into plants of

Camarosa in the first experiment were used to assess the susceptibility

of other cultivars to crown rot. The set-up was similar to the firstexperiment, except that the inoculum was sprayed onto the plants

rather than injected into the crown. This was to determine whether

some isolates were more aggressive than others under standard growing

conditions. The cultivars evaluated included Camarosa, Festival, Florida

Fortuna, Aussiegem, Sunblushgem and Suncoast Delight. The first three

cultivars are the main cultivars grown in southern Queensland. The

other cultivars are new lines recently released by DEEDI. There were six

inoculated plants and six control plants for each cultivar. At the end of

the experiment, the percentage of plants that wilted and died in each

treatment was calculated.

Thirteen out of the fourteen isolates that were pathogenic when

injected into healthy Camarosa plants were pathogenic when sprayed

onto healthy plants of the same cultivar. All the other cultivars were

susceptible to half or more of the test isolates. The plants took three to

ten weeks to collapse after the fungi were sprayed onto the crowns. This

was longer than in the first experiment when the plants were injected

with the pathogens. It was also

warmer in the glasshouse in the

initial experiment with Camarosa.

The percentage of plants dying

after they were sprayed with

inoculum of the crown rot

fungi was used to assess the

susceptibility of the cultivars to

the various pathogenic isolates

(see Table 2). When the main

fungus, Gc2 was the source of

the inoculum, Camarosa and

Aussiegem were rated as highly

susceptible, with more than eighty

percent of the plants dying. Theother cultivars were rated as

Apollo Gomez checking plants in the glasshouse after they have beeninoculated with the crown rot fungus.


22/34


moderately susceptible, with fifty to eighty percent of the plants dying.

When Cf was the source of the inoculum, Camarosa, Florida Fortuna,

Sunblushgem and Aussiegem were rated as moderately susceptible,

and Festival and Suncoast Delight rated as less susceptible (less than

fifty percent of plants dying).

There were also differences when Cgwas the source of the inoculum,although there were only two isolates of this strain used in the test.

Across the three different subpopulations, Camarosa was rated as highly

susceptible, and all the other cultivars rated as moderately susceptible.

An analysis across the six cultivars indicated that the Gc2 and Cg

genotypes were more of a problem than the Cfgenotype.

Table 2. The susceptibility of six strawberry cultivars to the three crown rot fungi found in southern

Queensland. Data show the percent of plants wilting and dying ten weeks after the plants were

sprayed with inoculum. There were six inoculated plants and six control plants for each test. Only

isolates that were considered pathogenic in the previous experiment were used.Cultivar Percent of plants dying

Glomerellacingulata(Gc2)

(n = 5)

Colletotrichumgloeosporioides

(Cg) (n = 2)

Colletotrichumfragariae(Cf)

(n = 8)

Overall

Camarosa 97 100 79 92

Festival 79 60 31 57

Florida Fortuna 67 90 52 70

Sunblushgem 70 83 54 69

Suncoast Delight 77 67 33 59

Aussiegem 93 83 65 80

Average 81 81 52

These experiments show that there were differences in the susceptibility

of the cultivars to the two main groups of crown rot fungi and

differences within the groups of cultivars. Overall, the plants were more

susceptible to Glomerella cingulata than toColletotrichum fragariae.

This last mentioned genotype is common among samples collected

from transplants that were grown in the strawberry nurseries in the

1990s, and does not appear to be associated with plant losses from the

current nurseries on the Granite Belt. There were insufficient data to

determine the relative susceptibility of the cultivars to Colletotrichumgloeosporioides.

All the cultivars were susceptible to some of the isolates of Glomerella

cingulataand some of the isolates of Colletotrichum fragariae. None of

the cultivars were resistant to all the strains of the fungi. Camarosa,

developed in California, was the most susceptible cultivar, with only

small differences in the other cultivars. Overall, the cultivars from Florida

were only slightly better than the cultivars from Queensland. These

responses should be taken into account in future breeding efforts.

There were insufficient data to indicate whether the fungi isolated from

alternate host plants are likely to infect strawberry fields in southernQueensland. It could also not be determined whether the fungi that are


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found on native and other plants are the original source of the fungi that

affect strawberry plants in Australia.

Screening of the crown rot fungi for resistance to prochloraz

This research examined the resistance of different subpopulations of

the crown rot fungi to the main chemical used to control the diseasein the strawberry nurseries at Stanthorpe. The experimental work was

conducted in the laboratory at the University of Florida.

Forty-one isolates of the crown rot fungi were grown on media in plastic

plates and then transferred to a plate with prochloraz (Octave) applied

in a continuous radial concentration gradient. For each isolate, the

concentration of the chemical required to give a fifty percent inhibition

of growth of the fungus on the plate was calculated. This term is called

the half maximal effective concentration or EC50

. The analysis showed

that the estimated EC50

ranged from 0.001 to 0.008 g per ml, with an

average value of 0.003 g per ml (see Table 3). Prochloraz is normally

applied at a rate of 6.44 g per ml to strawberry plants growing in the

field. Thus, the effective concentration of the chemical to reduce the

growth of the fungi by half is less than 0.1% of that used in commercial

applications. These data indicate that the fungi do not appear to show

signs of resistance to prochloraz.

Table 3. Summary of the fty percent effective concentration (EC50) for inhibition

of growth of the crown rot fungi by the fungicide prochloraz.

Species Numberof isolates

tested

Average EC50

(g per ml)Range in EC

50

(g per ml)

G. cingulata(Gc2) 23 0.003 0.002-0.008C. gloeosporioides(Cg) 4 0.003 0.002-0.005

C. fragariae(Cf) 14 0.002 0.001-0.005

Conclusions

Isolates of the three crown rot species (Glomerella cingulata,

Colletotrichum gloeosporioides and Colletotrichum fragariae) collected

from diseased strawberry plants were generally pathogenic to strawberry

plants. The major species affecting

transplants supplied from nurseries

located on the Granite Belt is Glomerella

cingulata. Camarosa was the most

susceptible cultivar to the major

pathogen and Florida Fortuna was the

least susceptible cultivar. There was no

evidence that the crown rot fungi have

become resistant to prochloraz, the prime

chemical used to control the disease in

southern Queensland. Future research on

crown rot should focus on Glomerella

cingulata, the main subpopulationaffecting strawberry plants in Australia.

Tracey Lo Grasso isolating the crown rot fungi from strawberryplants.


24/34


Proles of team members

Chris Menzel

Chris, a principal horticulturist, has conducted research for Australian

horticultural industries for 29 years, especially on tropical fruit. He isundertaking research to assess the performance of different planting

material for the strawberry industry and is also leader of the runner

quality and crown rot projects.

Mark Herrington

Mark is a principal horticulturist with DEEDI. He has over thirty years

experience in breeding horticultural crops, with direct involvement

in strawberry, tomato, capsicum, melon, zucchini, cucumber and

pumpkin. Mark has released more than 26 cultivars and breeding

lines, and published 90 refereed and conference papers. He leads the

subtropical component of the Australian strawberry breeding program,

where he is focussing on delivering cultivars accepted by growers,

marketers and consumers.

Louella Woolcock

Louella has worked with the strawberry team at Maroochy since 1999,

and provides technical assistance to the breeding program. Louella

is responsible for the day-to-day operations of the breeding work,

including maintenance of the parent material used in crossing, along

with the pollination and germination of new seed. She collects yearly

data on the yield and quality of the new seedling lines and potentialnew cultivars, along with information on the performance of the

current industry standards.

Lien Ko

Lien is a scientist with a degree in Horticulture and experience in plant

molecular markers and tissue culture. She has over 20 years experience

in the application of these techniques to improve the production

of ornamentals, sugarcane, cereals and tropical fruit. Lien has been

instrumental in developing the first genetically-engineered pineapples

with blackheart resistance and controlled natural flowering. She iscurrently involved in the assessment of these new pineapples in the

field, and is assisting the strawberry plant breeding team develop new

cultivars, and the pathology group to better diagnose plants with lethal

yellows.

Jonathan Smith

Jonathan has worked as an experimentalist at Maroochy for more than

ten years, supporting research on the biology, ecology and control of

pests and beneficial insects in citrus, passionfruit, custard apple, mango

and grape. His main focus has been on the control of mites and scales

affecting citrus orchards in Queensland, and he has been involved in


25/34


the evaluation of numerous species imported from overseas to control

these insects. Jonathan also has experience in the pests of strawberry

fields, having assisted crop consultants working with the industry on

the Sunshine Coast. He has worked closely with Don Hutton on lethal

yellows and other strawberry diseases.

Don Hutton

Don is a senior experimentalist with DEEDI. He has conducted research

on plant pathology for over 40 years. Dons primary interest has

been in integrated disease management of strawberries where he has

developed control strategies for the main diseases, including black

spot, grey mould and powdery mildew, and also for managing crown

rot in the nursery beds. He has assisted strawberry growers adopt soil

fumigants that are alternatives to methyl bromide, which was phased

out for most sections of the industry in 2005.

Apollo Gomez

Apollo is an experimentalist, and has over 10 years experience in

research and development with DEEDI in Nambour and Cairns, and

the Commonwealth Scientific Industrial Research Organisation (CSIRO)

in Darwin. He has provided technical assistance across a range of

disciplines within horticulture, including breeding, propagation,

orchard and nursery management, crop protection, diagnostics,

quarantine and eradication. Apollo has worked on a variety of crops,

including strawberry, macadamia, mango and cashew. Apollo currently

provides technical support for glasshouse and field research on

strawberry diseases at Maroochy.

Natalia Peres

Dr Peres has been an Assistant Professor of Plant Pathology at the Gulf

Coast Research and Education Center at the University of Florida since

2004. Natalia earned her Ph D degree in Plant Pathology, M Sci degree

in Horticulture, and B Sci degree in Agronomy from the Sao Paulo

State University in Botucatu in Brazil. Her research and extension

programs have focused on improving our understanding of strawberry

and citrus diseases. Of particular interest has been the development of

models to assist growers in scheduling fungicide applications for thecontrol of major diseases in these crops. Natalia has developed models

to predict the development of anthracnose and botrytis (grey mould) in

strawberries.

Dr Peres has advised two M S students at the University of Florida

and served as a member of the committee for two Ph D students.

She has also provided training for many international students and

visitors to Florida. Natalia is an active member of the American

Phytopathological Society (APS). She is helping Don Hutton and the

Plant Pathology team at Maroochy to develop strategies for the control

of crown rot and other diseases in strawberry plants.


26/34


Loraine Chapman

Loraine has 20 years experience in publications as a designer, desktop

publisher and editor for DEEDI. She has published more than 35

Agrilink crop information manuals and numerous crop field guides

on growing and marketing of horticulture crops. Other publications

include scientific reports, presentations and CDs for Maroochy researchand extension staff. She has also developed web sites, and edited/

published agricultural books, manuals and reports for international

projects, ICRAF, FAO (United Nations) and the Department for

International Development, UK (DFID).

Lindsay Smith

Lindsay has been working at Maroochy Research Station as a Technical

Assistant since the early 1990s. Initially, he worked on a project

examining options for the control of banana weevil borer with Dan

Smith and others. For many years, Lindsay helped with research on thecontrol and management of insect pests in citrus, working with Dan,

Jonathan Smith and Chris Freebairn. More recently, he has contributed

to the strawberry program at the centre, and has been helping with

the collection of yield data in trial plots. He has also been assisting

with efforts to control the main pests and diseases affecting strawberry

crops, including the work on lethal yellows and crown rot.

Mary Grace

Mary has been a Technical Assistant for the strawberry R&D team

at Maroochy since 2005. Her main focus has been to help Mark

Herrington and Louella Woolcock in the breeding program. Mary

has been assisting with the regular harvesting and assessment of the

breeding lines, along with the propagation of the new material and has

also contributed to the agronomic and plant pathology research.

Warwick Grace

Warwick works as a Technical Assistant to the strawberry program

at Maroochy, and has been a member of the team for more than

five years. He has been responsible for the maintenance of field and

glasshouse plants in the breeding experiments. Warwick has also

helped out with the research to improve nursery quality and the impact

of crown rot and other diseases on strawberry production. Warwick

has Certificates in Horticulture and the Application of Chemicals,

and enjoys living on the Sunshine Coast where he also does contract

mowing and spraying for strawberry growers and others.

Michelle Paynter

Michelle started work at Maroochy Research Station in Emerging

Technologies, after completing three months work experience with

the University of Queensland. She graduated in 2007 with a B Appl

Sci degree in Environmental and Horticultural Production. Michellejoined the strawberry team in 2008 to provide technical assistance in


27/34


the breeding program. Her duties at Maroochy include the pollination

of selected parents to produce the new breeding lines and germination

of the new seed. Michelle is responsible for virus-indexing of the new

material and for maintaining the breeding lines that are kept in tissue

culture. She has also undertaken research into the screening of new

cultivars for their tolerance or resistance to wilt caused by Fusariumoxysporum.

Sam Price

Sam graduated from the University of the Sunshine Coast in 2006 with

a B Sci degree (Hons in Marine Ecology). He started at Maroochy in

2007, assisting research on the agronomy of persimmon, stonefruit and

custard apple. Recently, he joined the strawberry breeding program

and has helped assess the two new cultivars Florida Radiance and

Parisienne Belle for approval for Plant Breeding Rights (PBRs). Sam

has investigated various technologies to increase the capabilities of the

breeding program.

Sharon Anning

Sharon completed a Dip Appl Sci with the Moreton Institute of TAFE

in 2002. After graduating, she worked in a laboratory assisting with

studies to improve the production of peanuts. Sharon has been helping

the strawberry research team at Maroochy over the last couple of years,

mainly working with the plant breeding and pathology groups.

Tali Grace

Tali is currently undertaking a school-based traineeship. She is enrolledfor a Certificate II in Horticulture at the TAFE in Nambour. Tali likes

working outdoors, and has been helping with the strawberry breeding

program at Maroochy, assisting with planting, growing, harvesting and

assessment of the new lines.

Geoff Waite

Geoff Waite has over 40 years experience as an entomologist. In 2007,

Geoff retired from his position at Maroochy, but is still involved in the

various strawberry programs at the centre. Over the past few years,

Geoff has helped out with the editing and production of the StrawberryR&D Update.

Edward Woolcock

Edward completed his high school studies in 2009, and has been

working at Maroochy for the past two years as a casual Technical

Assistant for the strawberry breeding group. He has been involved in

planting, harvesting and assessment of the new selections. Edward has

also provided help in the propagation and maintenance of the new

planting material. Part of his time over the last few strawberry seasons

was spent collecting data on fruit colour, rain damage and fruit shape.


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Jenny Cobon

Jenny is a Senior Experimentalist and has worked as a Nematologist

for DEEDI for the past 18 years. She has conducted research on

plant-parasitic nematodes, with special focus on diagnostics and crop

management, nematode ecology and soil health. Part of this research

has involved chemical and non-chemical methods of control ofthese parasites and the biodegradation of nematicides in soil profiles.

Jenny has extensive experience working on the burrowing nematode

(Radopholus similis) and the root-knot nematode (Meloidogynespecies).

She recently received a scholarship to travel to Scotland to study

techniques used to identify the potato cyst nematode which affects

crops in Australia.Jenny manages the Nematode Diagnostic Laboratory

located at the Ecosciences Precinct at Boggo Road in Brisbane.

Wayne ONeill

Wayne is a Plant Pathologist and has worked for DEEDI for 19 years.

His main areas of interest have included research on nematodes,

Fusarium wilt and soil health, especially in banana crops. Wayne

has been involved in numerous studies on nematodes, including

the use of biological control agents, rotation crops and integrated

crop management systems. He co-manages DEEDIs Nematode

Diagnostic Laboratory which first identified the bud and leaf nematode

(Aphelenchoides fragariae) in Queensland strawberry plants. Wayne has

been involved in studies aimed at improving our understanding of the

distribution and ecology of this new pest.


29/34


Industry extensionQueensland Strawberry Growers Association Meetings. Members of the

strawberry team attended the industry meetings held in February, May,

July and October and provided local growers with an update on project

activities.

Mark Herrington reported to the National Strawberry Varietal

Improvement Steering Committee (NSVISC) in February and October,

where he gave an overview of the latest breeding efforts. Mark also

attended The North American Strawberry Symposium at Tampa in

Florida in February 2011. Areas of interest included strengthening the

link between the two subtropical breeding programs at Nambour and

Wimauma.

Don Hutton and Apollo Gomez visited Florida in February 2011 to

attend theNorth American Strawberry Symposiumand to meet with

collaborating scientists from the University of Florida. The industry inQueensland shares many similarities with the industry in Florida. During

the visit, Dr Peres from the University committed to further research on

the control of diseases affecting strawberry fields in Australia. Laboratory

techniques to test for resistance of the crown rot and grey mould

fungi (Colletotrichumspecies and Botrytis cinerea) to fungicides were

proposed. These techniques will allow us to better screen chemicals used

to control these diseases in Australia. Don and Apollo also learnt about

new strategies to control crown rot, grey mould and powdery mildew

from presentations at the Symposium. These strategies have potential

application for the strawberry industry in Australia.

Don Hutton andLarissa Bartelat Maroochy.Larissa providesadministrative

support to the berryresearch program atthe centre.


30/34


Rod Edmonds, Don Hutton and Noel Vock at Maroochy. Rod co-ordinates external fundingapplications for berry researchers at the centre. Noel edited the rst Strawberry R&D

Update in 2005.

Former and current members of the berry research team at Maroochy.


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PublicationsCobon, J.A. and ONeill, W.T. (2011).Aphelenchoides fragariae a foliar

nematode on strawberries in south east Queensland. Proceedings of

the 18 th Australasian Plant Pathology Society Conference, Darwin,

Australia, p. 105.

Gomez, A. and Hutton, D.G. (2011). Strawberry cultivar response to the

four genotypes of Colletotrichum spp. associated with crown rot in

Australia. Proceedings of the North American Strawberry Symposium,

Tampa, Florida, p. 16.

Gomez, A.O., Hutton, D.G., Seijo, T.E. and Peres, N.A. (2012).

Pathogenicity analysis of isolates of four Colletotrichum spp.

genotypes from strawberry and alternative hosts in Queensland.

Seventh International Strawberry Symposium, Beijing, China

(Abstract).

Gomez, A., Hutton, D.G., Smith, L. and Menzel, C.M. (2011). Recent

studies on controlling crown rot in strawberry plants. Simply Red

(Queensland Strawberry Industry Promotions Council)23, 4-5.

Herrington, M.E. (2011). National strawberry varietal improvement

program subtropical regions. Horticulture Australia Limited

Strawberry Industry Annual Report, p. 2.

Herrington, M.E., Hardner, C., Wegener, M., Woolcock, L.L. and Dieters,

M.J. (2011). Rain damage to strawberries grown in southeast

Queensland: evaluation and genetic control. HortScience 46, 832-

837.Herrington, M.E. and Price, S. (2010). Fragariaxananassa. Redgem. Plant

Varieties Journal 23 (3), 99.

Herrington, M.E. and Price, S. (2010). Fragariaxananassa. Suncoast

Delight. Plant Varieties Journal 23 (3), 100.

Herrington, M.E. and Price, S. (2010). Fragariaxananassa. Aussiegem.

Plant Varieties Journal 23 (3), 102.

Herrington, M.E. and Price, S. (2010). Fragariaxananassa. Sunblushgem.

Plant Varieties Journal 23 (3), 103.

Herrington, M., Wegener, M., Hardner, C., Woolcock, L.L. and Dieters,M.J. (2012) Influence of plant traits on production costs and

profitability of strawberry in southeast Queensland.Agricultural

Systems106, 23-32.

Hutton, D.G., Cobon, J., ONeill, W. and Gomez, A. (2010). Bud and leaf

nematode in Queensland strawberry fields. Simply Red (Queensland

Strawberry Industry Promotions Council)20, 1-3.

Hutton, D.G., Gomez, A. and Mattner, S. (2011). Some experiences with

Macrophomina phaseolinaand its association with strawberry crown

rot in Australia. Proceedings of the North American Strawberry

Symposium, Tampa, Florida, p. 15.


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Hutton, D.G., Gomez, A., Smith, L. and Menzel, C.M. (2011). An update

on efforts to control plant and fruit diseases in strawberry fields in

Queensland. Simply Red (Queensland Strawberry Industry Promotions

Council)22, 12.

MacKenzie, S.J., Gomez, A., Hutton, D. and Peres, N.A. (2010). Molecular

characterization of Colletotrichumpopulations causing crown rot of

strawberry in Australia. Phytopathology100 (Supplement), S75-S76.

Menzel, C.M. (2011). Controlling crown rot in strawberry fields. Horticulture

Australia Limited Strawberry Industry Annual Report, p. 3.

Menzel, C.M. (2011). Improving the quality of strawberry transplants.

Horticulture Australia Limited Strawberry Industry Annual Report, p. 5.

Menzel, C.M. (2011). Update on strawberry projects. Department of

Employment, Economic Development and Innovation, 1 p.

Menzel, C.M. and Smith, L. (2011). The relationship between cropping and

the size of nursery material in strawberry. Simply Red (Queensland


Menzel, C.M. and Smith, L. (2011). Small Florida Fortuna plants again

this season. Simply Red (Queensland Strawberry Industry Promotions

Council)23, 7-8.

Menzel, C.M. and Smith, L. (2011). Effect of time of planting, plant size

and nursery-growing environment on the performance of Festival

strawberry in a subtropical environment. HortTechnology 21, 56-66.

Menzel, C.M. and Smith, L. (2011). Transplant quality affects the production

of Festival and Florida Fortuna strawberry plants growing onthe Sunshine Coast. Simply Red (Queensland Strawberry Industry

Promotions Council)26, 7-9.

Menzel, C.M. and Smith, L. (2011). The protected culture of strawberry

plants growing under plastic tunnels. Simply Red (Queensland


Menzel, C.M., Waite, G.K. and Chapman, L. (2010). Strawberry R&D Update.

Department of Employment, Economic Development and Innovation,

Nambour, 36 pp.

Pavan, W., Fraisse, C.W. and Peres, N.A. (2011). Development of a web-

based disease forecasting system for strawberries. Computers and

Electronics in Agriculture75, 169-175.

Peres, N.A., MacKenzie, S., Fraisse, C. and Pavan, W. (2011). A disease

forecast system for control of anthracnose and botrytis fruit rots.

Proceedings of the North American Strawberry Symposium, Tampa,

Florida, p. 15.

Smith, J., Neave, M., Hutton, D. and Gibb, K. (2012). First report of

rickettsia-like bacterium associated with strawberry lethal yellows

detected in leafhopper,Austroagallia torrida(In preparation).


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AcknowledgementsThis update includes summaries of research conducted from the

Horticulture Australia Limited strawberry Projects BS06005, BS09013 and

BS10008.

We thank Horticulture Australia Limited (HAL), Queensland Strawberry

Growers Association, Strawberries Australia, Florida Strawberry

Growers Association, Sweets Strawberry Runners, Red Jewel Nursery,

Perry Strawberry Runner Growers, Tasmania Highland Strawberry

Runners and Toolangi Certified Strawberry Runner Growers Co-operative

Limited. Special appreciation is extended to Lourens Grobler and Jennifer

Rowling, and the farm staff from Maroochy, Bundaberg and Redlands

Research Stations. We also thank Vance Whitaker and Craig Chandler

from the University of Florida.

This edition of the update was edited by Chris Menzel and Geoff Waite,

and typeset by Loraine Chapman.


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Team members

Plant breeding

Mark Herrington, Louella Woolcock, Sam Price, Michelle Paynter, LienKo, Mary Grace, Tali Grace, Warwick Grace, Edward Woolcock, Sharon

Anning, Amanda Westacott, Kathy Parmenter and Denis Persley

Agronomy

Chris Menzel and Lindsay Smith

Entomology

Jonathan Smith, Don Hutton, and Matthew Neave and Karen Gibb

(Charles Darwin University)

Plant pathology

Apollo Gomez, Don Hutton, Lindsay Smith (DEEDI), Teresa Seijo and

Natalia Peres (University of Florida), and Jenny Cobon and Wayne ONeill

(DEEDI, nematodes)

Administration support

Larissa Bartel, Rod Edmonds, Debby Maxfield and Loraine Chapman

For more information contact:

Chris Menzel

Phone: + 61 7 5453 5945

Facsimile: +61 7 5453 5901

Email: [email protected]

On 26 March 2009, the Department of Primary Industries and Fisheries

was amalgamated with other government departments to form the

Department of Employment, Economic Development and Innovation.

The State of Queensland, Department of Employment, Economic Development

and Innovation, 2009.

Except as permitted by theCopyright Act 1968, no part of the work may in any form or by any

electronic, mechanical, photocopying, recording, or any other means be reproduced, stored in

a retrieval system or be broadcast or transmitted without the prior written permission of theDepartment of Employment, Economic Development and Innovation. The information containedherein is subject to change without notice. The copyright owner shall not be liable for technical

or other errors or omissions contained herein. The reader/user accepts all risks and responsibilityfor losses, damages, costs and other consequences resulting directly or indirectly from using this

information.

Enquiries about reproduction, including downloading or printing the web version, should be directed

to [email protected] or telephone +61 7 3225 1398.

Not all the chemicals mentioned in this report are currently registered for use on strawberry runneror fruit production fields. Please check current registrations for strawberries before using any of the

chemicals. The product label is the official authority and should be used to verify all data relating to

the use of a chemical.

Strawberry Update 2011

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