Phylloxera in the Yarra Valley:
A case study
Phylloxera and Grape Industry Board of SA
April 2010
Acknowledgements
The PGIBSA would like to acknowledge and thank the individuals and companies who contributed to the
research underpinning this report. They are:
Steve Weber
Willy Lun
Mark O’Callaghan
Damien DeCastella
Bethany Collins
David Ammerlan
Xavier Mende
Sharon Hebbard
Tony Jordan
Richard Howden
Kevin Powell
Greg King
Dan Dujic
Stuart Holland
Richard Hamilton
De Bortoli Wines
Yering Station
Yarra Burn Winery (Constellation Wines)
(Previously) Foster’s Wine Estates
Foster’s Wine Estates
Foster’s Wine Estates
Coombe Farm
Hebbard Consulting (Train Trak vineyard)
President, YVWGA
Executive Officer, YVWGA
DPI Victoria Biosciences Research Division
DPI Victoria Plant Standards Branch
Domaine Chandon
DPI Victoria and Victorian Viticulture Biosecurity Committee
Foster’s Wine Estates
Disclaimer
While every effort is made to ensure the accuracy and integrity of the information contained in this
document, no responsibility is taken for any errors or omissions. The Phylloxera and Grape Industry Board
of South Australia expressly disclaims any liability for the accuracy and sufficiency of the information, and in
no circumstances shall it be held liable for the consequences of decisions, actions, assumptions and
interpretations made by those who use the information contained within the report.
It should be noted that the opinions expressed by the author are not necessarily endorsed by DPI Victoria
or any of the other individuals or organisations consulted as part of the case study. Comments made by
interviewees that are reported in this document are not necessarily factually correct.
© Copyright PGIBSA August 2010
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Contents
Acknowledgements .......................................................................................... 2
Contents ........................................................................................................... 3
Executive summary .......................................................................................... 5
Background ....................................................................................................... 6
Overview of events........................................................................................... 7
Case study themes ............................................................................................ 9
1. Original discovery .......................................................................................................... 9
2. Initial response ............................................................................................................ 12
3. Attempted eradication of Beavis infested block ........................................................... 13
4. Surveys and monitoring ............................................................................................... 16
5. Boundary determinations ............................................................................................ 20
6. Effects of the infestation and quarantine restrictions on business operations ............. 25
7. Implementation of protocols and other protective measures ...................................... 27
8. Progress of phylloxera infestation and replanting plans ............................................... 34
9. Expected long term effects on the region .................................................................... 39
Summary and recommendations ....................................................................40
Summary of findings ........................................................................................................ 40
Recommendations........................................................................................................... 41
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Executive summary
Grapevine phylloxera was found in the Yarra Valley in one vineyard in December 2006. Subsequent
detections were made in four vineyards in November – December 2008. A Phylloxera Infested Zone (PIZ)
has been declared within the Yarra Valley, leaving approximately one third of vineyards inside the PIZ and
two thirds outside. Since December 2008, no further infestations were discovered in the region until a
detection was announced in a vineyard near the centre of the PIZ in late March 2010.
In February 2010 research was conducted for a case study on the Yarra Valley phylloxera outbreak. The
aims of the case study were:
 To document the main events in the progression of the outbreak and its management – from the
initial detection in 2006 up to vintage 2010;
 To describe the impact of the outbreak on growers and winemakers in the region;
 To describe strategies adopted in managing the impact of the infestation – including
implementation of protocols and replanting plans;
 To identify issues that arose as the local industry and authorities dealt with the outbreak and the
subsequent establishment of a quarantine zone; and hence
 To make recommendations for actions that could be undertaken by the PGIBSA and/or
grapegrowers in South Australia that would either reduce the likelihood of, or assist in the
management of an outbreak of phylloxera in a region in SA.
The main findings from the case study were:
 Given the right conditions (soil type, phylloxera genotype and climate/weather), phylloxera can
cause very rapid decline in affected grapevines
 Eradication was not successful in this region – despite apparently very early detection
 Emergence traps can be better than root surveys for detecting phylloxera
 It can be very difficult to determine the source of a phylloxera infestation
 Growers’ initial reaction can be highly emotional and confrontational
 Boundary determinations are subject to political pressures and practical issues – not just
biosecurity considerations
 Wineries would generally prefer to be inside a PIZ than outside it (if their fruit is inside)
 Some concessions in the application of regulations were necessary to allow market access
 The implementation of protocols is not consistent across the PIZ or the wider region
 Replanting is not being treated as an urgent priority
 For most people, the arrival of phylloxera in the district did not have an immediate and devastating
impact.
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Background
In 2009-10, the PGIBSA undertook a case study of the phylloxera outbreak in the Yarra Valley. The aims of
the case study were:
 document the main events in the progression of the outbreak and its management – from the
initial detection in 2006 up to vintage 2010;
 describe the impact of the outbreak on growers and winemakers in the region;
 describe strategies adopted in managing the impact of the infestation – including implementation
of protocols and replanting plans;
 identify issues that arose as the local industry and authorities dealt with the outbreak and the
subsequent establishment of a quarantine zone; and hence
 make recommendations for actions that should be undertaken by the PGIBSA and/or grapegrowers
in South Australia that would either reduce the likelihood of, or assist in the management of an
outbreak of phylloxera in a region in SA.
The methodology was a combination of reviewing documents relating to the case study and interviewing
members of industry and government with various different perspectives and experiences related to the
outbreak.
Themes that were considered during the research included:
 Original discovery
 Initial response
 Eradication attempt
 Surveys and ongoing monitoring
 Boundary determinations
 Effect of infestation and quarantine restrictions on business operations
 Implementation and effectiveness of protocols
 Replanting plans
 Long-term effect on region
The case study is presented as a discussion under each of these themes – rather than chronologically. Each
section is intended to be able to be read independently of the other sections – therefore there is some
repetition of core facts where necessary.
An overview at the beginning of the report gives a chronological summary of the main events.
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Overview of events
Figure 1: Yarra Valley GI region showing quarantine zone. Souce: Yarra Valley Winegrowers Association.
In early December 2006 phylloxera was discovered in a vineyard in the Yarra Valley. The property was
immediately quarantined, and a 5km radius quarantine zone (fig. 1) was declared around the property
boundary. Root surveys were undertaken of all vineyards within the zone and in associated vineyards
outside the zone to delimit the extent of the outbreak. No further infestations were found.
A meeting of growers was held on December 13, 2006, which was attended by approximately 300 growers,
as well as representatives of the Yarra Valley Winegrowers' Association (YVWA), DPI Victoria Plant
Standards and DPI Victoria Biosciences Research division.
The Maroondah PIZ was officially gazetted on 1 March, 2007. This was essentially the original 5km radius,
adjusted for natural boundaries such as roads and rivers and also to include a contract processing winery
on the north-western edge of the zone. Within the Yarra Valley GI region there were approximately
1100ha of vineyards inside the quarantine zone and 2500ha outside.
A seven hectare portion of the vineyard, where the initial detection was made, was poisoned with repeated
herbicide applications by the owners, in an attempt to eradicate the phylloxera from the vineyard and
hence – if this were to prove to be the only infested site – from the region.
In mid-November 2008 another detection was made, in a vineyard over the road from the original site.
This was followed within a few weeks by three more detections: two in the same road as the first two and
the third in a vineyard some distance away (approximately 4km as the crow flies or 8km by road) owned by
the same company as the originally infested site. DNA-testing confirmed three of the subsequent
detections as the G1 phylloxera genotype (the most widely distributed genotype found in Australia to date).
A public meeting of growers was convened by the Yarra Valley Winegrowers’ Association on 15 December
2008. This was attended by approximately 150 growers. Two opinion surveys were conducted of growers
in the region (one before and one after the meeting) to determine their preferences for the new boundary
of the PIZ – which needed to be extended at least enough to remain 5km from the furthest infested site.
The recommendation of the Association was that the PIZ be extended to include the whole Yarra Valley GI
region. 72% of growers voted in favour of this option in the second survey; however DPI Plant Standards
did not accept that recommendation because it did not have 100% support from industry and was not
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justified on technical grounds. Instead the boundary was extended initially by the minimum required and
subsequently (within a few months) to take in three “peninsulas” that each included one large winery that
had requested to be included in the zone. This latest boundary of the Maroondah PIZ was gazetted in
November 2009.
A major bushfire in February 2009 burned the originally infested property. This vineyard has since been
sold to the neighbouring grower (who also owns two of the recently detected infested blocks) and has been
replanted to apples. The fire also had a significant effect on the 2009 harvest – reducing the wine produced
from the region by up to 75%, mainly as a result of smoke taint.
As at mid-March 2010 there had been no further detections of phylloxera either inside or outside the
Maroondah PIZ within the Yarra Valley. Some vineyards are being monitored by growers using emergence
traps, and research monitoring is being conducted in one vineyard by DPI Biosciences Research, but no
further delimiting survey work is being conducted by DPI Plant Standards.
Note: On 19 March 2010 another property owner in the region advised local industry members that it had
found phylloxera in its own vineyard off the Maroondah Highway – very near the other infested vineyards
on St Hubert’s Road. The genotype was confirmed as G1.
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Case study themes
1. Original discovery
Phylloxera was positively identified in a section of eight-year-old ungrafted Cabernet Sauvignon vines in the
Foster’s owned Beavis vineyard on St Hubert’s Road in early December, 2006. The previous autumn, vines
in the area were observed to be yellowing prematurely, and the regional manager checked the roots for
signs of phylloxera, but none were found. Although phylloxera was “on the list of possibilities”, the most
probable cause was considered to be lime-induced chlorosis.
Very dry conditions prevailed in winter and spring 2006. The vines continued to be monitored closely. In
spring 2006 they showed normal bud-burst, with no canopy symptoms apparent. However, after a severe
frost in October 2006, which burnt the shoots back to the cordon, this section of vines did not recover.
Root inspection on 1 December revealed phylloxera galls, and DPI Victoria Plant Standards was immediately
contacted. Confirmation was made and the first press release issued on 4 December 2006.
Aerial imagery taken of the vineyard in February 2006 as part of Foster’s’ routine monitoring program
showed no evidence of the infested section of vines. However, by February 2007 the aerial imagery clearly
showed a low vigour patch typical of phylloxera damage in the location of the infested vines (see figure 2
below).
Comparative aerial imagery photos of the infested block taken 12 months apart. Source: R Hamilton, Fosters' Wine Estate.
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The decline in the originally infested vines was very rapid after the frost occurred in spring 2006 (fig 3).
Beavis vineyard - February 2007. Source: PGIBSA.
The dominant factor in this rapid decline, according to Dr Kevin Powell, was almost certainly genotype as all
the scientific evidence so far highlights that G1 is more virulent than the other genotypes tested so far
(apart from G4) and has been found in all PIZ regions with the exception of the King Valley and Buckland
Valley.
It has been observed in population monitoring studies that when vines get stressed under drought
conditions (this can be due to both heat stress and lack of water) phylloxera populations increase in the
subsequent season. The expression of phylloxera symptoms (which are similar to water stress symptoms)
also increases after drought, making it easier to identify a weak spot.
How did phylloxera get to the Yarra Valley?
A thorough traceback was conducted by DPI Victoria Plant Standards staff – using the records kept by
Foster’s. No conclusions were able to be drawn about the source of the infestation based on the
paperwork. Nursery material was identified as being sourced from PEZs, and no evidence of breach of
protocols could be found relating to contractors.
At the time, it was not known whether this would turn out to be an isolated infestation in the region, or
whether more infestations (which might have occurred earlier) were about to be detected.
The people interviewed for the case study had varying opinions as to the source of the infestation and
whether they saw it as surprising or expected that phylloxera had come to the Yarra Valley. Comments
made1 included:
 The fact that it’s moved means someone has broken the law.
 Clothing – we forget about this. Most people now use big crews (labour gangs)
1
It should be noted that these comments are reported here as closely as possible to how they were made. There is no
implication that they are factually correct.
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 Always thought it would happen – [because of] wineries associated with known infested vineyards
in other regions, contractors coming in from other regions, general public don’t have knowledge
 Behaviour of chemical suppliers and consultants travelling between regions – don’t follow any
protocols
 [There is a] history of association with winemakers from NE Victoria – no protocols in place
 Industrial sabotage is a definite possibility
 An outbreak was inevitable – [phylloxera is] less than 100km away: tourists, links to King Valley in
general farming, Kangaroo Ground had phylloxera in the 1800s
Discussion
The experience at Beavis shows that even with a vigilant vineyard manager, phylloxera was missed in the
early stages by root inspection and by aerial imagery. The dramatic frost event on top of prolonged
conditions of water stress may have led to a more rapid decline than would otherwise have been the case.
It would be interesting to know whether the phylloxera would have been found that spring if these
conditions had not occurred; and also whether a DNA test of a soil sample or an emergence trap would have
detected phylloxera when it was first suspected, in autumn 2006 – six months earlier.
Despite a thorough traceback conducted by DPI Victoria, and despite the fact that Foster’s had kept very
good records and had maintained good hygiene protocols, no definite conclusions have been able to be
drawn about the source of the Beavis infestation. The location of the original infested vines (near the centre
of the block) was unusual for an accidental introduction by a casual visitor, and protocols for machinery and
vineyard workers appeared to be appropriate. Deliberate sabotage was even suggested as a possibility
(unofficially) by one interviewee - because of the lack of any more obvious cause. It was suggested that
Beavis had had an “unhappy employment history” – however there is little evidence of that. When the first
outbreak was detected, Foster’s had owned the property for nine years, having bought it from the original
owners in 1997. The suggestions made by interviewees as to the cause of the infestation included
consultants, suppliers, winemakers, tourists, general public, wineries, general farmers and labour gangs –
only one person suggested that it was a violation of a quarantine regulation. These suggestions are pure
conjecture and were not supported by any evidence – however it is an interesting insight that most people
speculated that it was a non-regulated risk vector (people) rather than machinery, planting material or
grape products.
At the time, Beavis vineyard management felt that this was unlikely to be the original infestation in the
Yarra Valley. However, so far (three years on) the only subsequent detections appear to be more recent
infestations than the one at Beavis, on the basis that they are all on ungrafted vines in similar soil and
climate conditions and would therefore be expected to decline at a comparable rate 2.
However, it is still possible that an earlier infestation is present in the Valley but has not been
detected/reported. This could be the case on grafted vines, or where soil characteristics made symptoms
take longer to appear, or even if unhealthy vines were removed without the cause of their decline ever
having been confirmed.
The G1 genotype is found in all other infested regions in Australia except the King Valley and Buckland
Valley. Even in the King Valley it is possible that G1 exists but has not been found (phylloxera has not been
DNA-typed in the King Valley since 2002 – and of course only a sample of phylloxera in a region is ever
typed). Therefore it is not possible to identify where the Yarra Valley infestation came from, how long it has
been present in the Valley, or by what means it was introduced. It is not even possible to estimate how long
it was in the Beavis vineyard before it was detected.
2
Although this cannot be concluded with certainty
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2. Initial response
After the press release was issued, a meeting was held on 13 December 2006 in Lilydale, which was
attended by approximately 300 local growers and other industry stakeholders. Reactions of growers were
reported to be “as expected” – ranging from pragmatic to very angry. Recollections of the meeting are that
it was at times very heated and highly emotional, with blame and anger directed at Foster’s for having
“brought phylloxera to the Yarra Valley”. It was also reported that some growers seemed to have very
little understanding of “the basics” about phylloxera.
However, it was felt that Foster’s communicated well and that their actions in response to the detection
were appropriate (even commendable), as was the handling of the outbreak and introduction of quarantine
restrictions by DPI Victoria Plant Standards Branch and the role played by the Yarra Valley Winegrowers’
Association. Communicating well and “getting information out to people quickly” was thought to have
minimised the negative response.
Discussion
Foster’s’ proactive, transparent and well communicated response to the outbreak must have gone some
considerable way to reducing negativity towards them. As well as quickly putting in place a plan to attempt
to eradicate the phylloxera from the infested section of the vineyard, Foster’s immediately built a heat shed
over the road from Beavis at their St Hubert’s vineyard, and allowed other growers and wineries access to
the facility.
The strong emotional reaction by some growers at the public meeting may have been due to a lack of
knowledge and fear of the unknown. One interviewee who was at the meeting said it “defies logic” that the
reaction by some growers was so strong, “visceral” and irrational – when the recent history of phylloxera
outbreaks in Australia and around the world (eg Oregon, Marlborough) is that the industry survives well
despite the medium term economic impact.
With such a large audience from different backgrounds and with different degrees of knowledge about
phylloxera, it was suggested by one interviewee that some might have got lost in the amount of information
that was presented at that meeting, while some would not have had the basic knowledge about phylloxera
that was assumed in the presentations. It is also likely that the shock of the initial news would have made it
difficult for people to absorb subsequent practical details. A series of nine follow up meetings were held in
the region, however, organised by Grapecheck (a horticultural extension program provided by DPI Victoria)
and conducted by Dr Powell and others. These workshops included bus tours to other infested regions to
give growers an opportunity to observe how other regions managed phylloxera and the implementation of
protocols. They also included information on rootstock selection. These meetings are considered a very
important part of the process of helping growers to respond to the outbreak and consequent compliance
requirements.
The fact that the second industry meeting held in 2008 was so much calmer, as well as being attended by
only about half as many people, suggests that by then growers had obtained enough information to feel
more confident about dealing with the situation. The question is whether it is possible to avoid the
negativity, anxiety and conflict of a “first meeting” in a new outbreak situation – eg in South Australia – by
providing enough information and examples beforehand. The Executive Officer of the YVWGA indicated the
critical importance of having accurate information available and distributed very quickly – to prevent the
spreading of misinformation and to counter anticipated opposition. “Have answers ready to go....don’t
make decisions on the fly if possible.” Another tip was: “Don’t assume people know the basics [about
phylloxera+”.
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3. Attempted eradication of Beavis infested block
For two years, Beavis was the only block in the Yarra Valley known to be infested. No other infestations
were found during the surveys conducted by DPI Plant Standards in the initial PIZ, and no further phylloxera
detections were made outside of this vineyard between December 2006 and November 2008.
An eradication program was developed by Foster’s and commenced in summer 2007. Population data from
emergence traps placed throughout and surrounding the known infested area3 was used to help determine
the extent of the eradication program. A total of seven hectares was included in the initial program. 20
rows on either side and 15 panels on each end of the infested section were left untouched initially, while
the surrounding rows were killed first – to remove the vine roots as a food source and hence try to prevent
the phylloxera spreading outwards when the infested vines were killed (see fig 4 below – taken in March
2007). A surface spray of aphicide was also applied to the buffer vines and surrounding headlands
beforehand to limit crawler movement. Once the “buffer” vines were believed to be dead, the centre
section was poisoned (about six weeks later). Vines were not removed immediately – giving time for the
chemicals to fully penetrate the roots first. The aim was to ensure that all roots were completely dead
before removing the vines. Emergence traps were left out to monitor any post-herbicide emergence.
Figure 4: removal of buffer vines around infested site - March 2007. Source: R Hamilton, Fosters' Wine Estates.
The original plan was to remove the (dead) vines in spring 2008, mulch and work the ground, then plant
and work a summer crop in 2009. The ground would be prepared for planting in autumn 2009 and
replanted (on grafted vines) in spring 2009 – just over two years after the original vines were killed. In fact,
the vines were not removed in spring 2008 as they were found to have suckers. Then, in early March 2008,
emergence traps were put out in strategic locations elsewhere in the Beavis vineyard and after two weeks
phylloxera was found in three of the traps (see fig 5 below).
Once more phylloxera had been found in Beavis it was decided to destroy the remaining 23 hectares of the
Beavis vineyard. This was carried out in autumn 2008 – before any further detections had been made
elsewhere in the Valley. The eradication program for the whole vineyard – even without removal of vines –
took 187 hours of Foster’s’ labour plus an estimated $25,000 for contractors, poison etc. The budget for
removal of vines and roots was $50,000.
3
originally part of a research study conducted by Dr Kevin Powell and funded by GWRDC to determine population
abundance and measure the risk of further spread
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Figure 5 Location of traps and detection sites on Beavis vineyard in 2008. Source: D Ammerlan, Fosters' Wine Estates.
Then, before the removal program commenced, the vineyard was sold in 2009 to a neighbouring property
owner, some months after the whole vineyard was severely burnt in the February 2009 bushfires (fig 6).
Burnt vines on Beavis property Feb 2009. Source: R Hamilton, Fosters' Wine Estates.
All vines remaining in the 32 hectare block have now been removed (by the new owners) and the land
cleared ready for replanting with apple rootlings.
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Discussion
The fact that phylloxera was found elsewhere in the Beavis vineyard in autumn 2008 and then in
neighbouring properties in spring/summer 2008 means that the eradication attempt has proven to be
unsuccessful in preventing the spread of the infestation. It is quite possible that the other infestation sites
on Beavis were already present by the time the original detection site was removed - or even when it was
first detected.
One suggestion made was that the removal of the whole Beavis vineyard (32 hectares) might have been
more successful and prevented the spread of the infestation to the neighbouring properties and the
Racecourse vineyard. It appears on the basis of the extent of decline (all are on own roots) that these
infestations are likely to be more recent than the Beavis infestation but for this suggestion to be correct,
they would have to have occurred after the original detection site was destroyed. This seems unlikely, given
that the infestation at Coombe Farm could only have been a few months old when detected if it occurred
after the original vines were killed4. Also the number of insects found in traps in the rest of the Beavis
vineyard was low, which reduces the probability that the infestation spread from these locations.
One theory put forward is that the infestation at Coombe Farm came from Beavis on the hooves of sheep
that grazed on both properties each winter between 2003 and 2006 (always Beavis before Coombe Farm in
a season) – in which case the infestation on Coombe Farm had already happened prior to the eradication
attempt at Beavis. (NB This theory is not considered very likely by Dr Kevin Powell, because it would require
that the sheep collected overwintering crawlers on root material from the infested block, as phylloxera
would not have been above ground during winter when the soil temperature is below 15˚C.)
Even if a larger-scale vine removal would have prevented the spread to the neighbouring properties (at least
in the short term), the detection at Racecourse means that phylloxera was already present elsewhere in the
Valley - making it very unlikely that it could continue to be contained. Ultimately, the eradication attempt
proved to be futile, despite the apparently early detection of the infestation (early in terms of the amount of
time for which canopy symptoms had been apparent and the fact that it was the first detection in the region
- rather than in terms of the length of time the phylloxera had been present in the soil, which could be
several years). Given the history of phylloxera in Australia and what is known about its biology and
behaviour, general opinion prior to the eradication attempt was that this would not be successful 5.
The outcome is further evidence that eradication is not likely to be a viable option even for an apparently
small and promptly detected infestation. [Although it should be noted that the phylloxera detected in Upton
in 2000 has not shown up in any vineyard beyond the originally infested property after ten years – which
means that, had the infested vineyard been removed when the phylloxera was first detected, it might have
been eradicated from that region.]
4
Dr Powell's opinion is that it is more likely that the infestation was at least one season old when detected,
particularly when considered in light of its distribution the following season
5
Dr Powell specifically recommended against the attempted eradication and use of herbicide, as it had never been
demonstrated to work before.
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4. Surveys and monitoring
Root survey program
Once the first infestation was confirmed, a survey program was initiated for the area inside the quarantine
zone boundary (1100ha) plus another 200ha outside the zone based on known associations with the
infested vineyard. Ground surveys in accordance with the national survey protocol were conducted by
three teams each comprising a team leader from DPI Plant Standards and approximately seven team
members supplied by the rezoning contractor used by DPI Plant Standards for the PEZ upgrade program or
a local vineyard contracting firm. The total cost to the Victorian government of the Yarra Valley surveying
in 2006/07 was $187,000.
To identify the vineyards that needed to be surveyed, DPI staff had to drive along all the roads within the
defined quarantine zone, as there was no comprehensive database of growers. Local industry people
assisted with ownership details.
No more infestations were detected during the survey program. As a result, the quarantine zone boundary
was confirmed and gazetted. No further survey work was then undertaken.
Two years later, phylloxera was detected by growers in four other properties in the PIZ – all of which were
surveyed in summer 2007. The detections were confirmed on three of the properties by DPI Plant
Standards, and DNA-testing was done, which identified the genotype as G1. The fourth property was not
checked as it was reported by the same grower who reported another of the detections and owned both
(adjoining) properties. It has still not been confirmed by a DPI inspector or researcher.
When the PIZ boundary was extended, there was very little further surveying done as there were not many
vineyards affected by the boundary change. Approximately four vineyards were surveyed for market
access purposes. No phylloxera was found.
The research team at DPI Victoria Biosciences Research Division, led by Dr Kevin Powell, has conducted
research at the Beavis site comparing different methods of phylloxera detection: root surveys, emergence
traps and DNA assays. In this single season pilot study, they found that both DNA assays and emergence
traps were more sensitive than the standard root surveys and both had the advantage of also providing
quantitative information about the abundance of phylloxera populations present and hence potentially
about the virulence of the genotype and/or the age of the infestation (Herbert et al 2008). DNA assays
have the additional advantage that they can potentially be used at any time of year 6, and compared with
emergence traps they do not require a repeat visit to the vineyard to collect the sample and they do not
have the problem of being knocked by vineyard equipment. The processing cost for the sample is the
major expense with this method.
The YVWGA questioned the effectiveness of the root surveys conducted by DPI Plant Standards at a
meeting with representatives of the Plant Standards Branch in May 2009 – and suggested that emergence
traps might be cheaper as well as being more effective. DPI Victoria Plant Standards concur that this is a
better method of detection but are not willing to change over until a nationally accepted protocol for using
the traps has been developed. (This is currently under investigation in a research program co-funded by
industry and the Victorian government.)
6
Most recent findings by the research team at Coombe Farm suggest that this may not be correct
Yarra Valley case study 2010
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Discussion
The fact that phylloxera was found two years later in vineyards surveyed as part of the original outbreak
response has led to a perception within the region that the root survey method is ineffective. Almost every
person interviewed for the case study stated without prompting that they felt the survey program was not
accurate and could not be relied on – a “waste of money” and creating a “false sense of security”. It was
commented that the protocol only requires 2% of vines to be surveyed – and only a small portion of the
roots of that 2%. [In fact the survey is more effective than this because it targets weak vines, which gives it
a greater likelihood of detecting an infestation than an entirely random sample.] It was also noted that
emergence traps found phylloxera in other parts of the Beavis block where root surveys conducted at the
same time did not.
It was commented that vineyards in the PRZ outside the quarantine zone were able to send their fruit into
PEZs elsewhere in Victoria and in NSW if they had their vineyards surveyed; however, without confidence
that the surveys could detect early infestations, this was felt to be risky and could discourage a winery from
purchasing the fruit and/or compromise the safety of the regions to which the fruit was being sent. This
was considered to be potentially divisive in the local industry.
It was also commented that the reliance of the national upgrade program on root surveys was similarly risky
– and could lead to PEZs being declared where phylloxera has been missed. [This argument is not
sustainable as the upgrade survey requires at least two surveys over three years, with legislative protection
introduced to prevent an infestation in the intervening time. The purpose of the initial survey when a
detection has been made is to delimit the extent of the infestation at that time in order to define a
quarantine zone. Had a follow-up survey been conducted as part of the PIZ determination protocol, as it is
for the upgrade protocol, then the new sites (and possibly others) would very likely (although not certainly)
have been found. It should also be noted that the recent Mansfield detection was made by a root survey
team from DPI Victoria Plant Standards branch as part of a market access survey in a vineyard where no
visual canopy symptoms were evident. ]
DNA genotyping of phylloxera is not a standard component of the national survey protocol; however DPI
Plant Standards includes it as part of their methodology. All detections so far in the Yarra Valley (except
one) have been genotyped by Kevin Powell. This provides valuable information as it should not be assumed
that all detections will necessarily be the same genotype, and rootstock recommendations and
management plans depend on knowledge of the phylloxera genotype and its behaviour. The cost of this
service in Victoria is incorporated in the funding provided by DPI to the research team. It is suggested that
this step be included as standard practice in the South Australian phylloxera contingency management plan.
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Ongoing monitoring
It is not known to what extent growers are monitoring their own vineyards, but it was felt by people
interviewed that growers all have a good understanding of how to find phylloxera – having attended
workshops organised by the Association - conducted on the Beavis vineyard in conjunction with DPI Victoria
Biosciences Research Division (over 100 attendees in total).
One grower said that he is “not actively monitoring, but mindful of the possibility”. The YVWGA Best Practice
Guidelines and Protocols for Pest and Disease and Phylloxera Management for the Yarra Valley includes the
following advice for growers: “Monitor vineyards regularly for signs of vine decline and notify DPI
immediately of any suspect areas.”
Case study – Foster’s vineyards
The Foster’s’ vineyard management team in the Yarra Valley conduct monitoring of two of their vineyards
in the Yarra Valley –the Racecourse vineyard (infested) and St Hubert’s vineyard adjacent to Coombe Farm
(as yet showing no signs of infestation). Despite obtaining aerial imagery of the vineyards each year and
processing it to identify weak spots, their experience is that this is not the most effective detection method
– because of the enormous variation that occurs between varieties, blocks and seasons regardless of
phylloxera. It is also time-consuming as all identified weak spots need to be “ground truthed” by root
surveys. In practice, they find it more effective to use emergence traps. These are placed in all areas of low
vigour (identified by a combination of examination of the PCD maps and visual assessment on the ground),
rather than in the random sampling grid pattern used in the standard root survey program. (This is
considered to be ineffective as it only samples 2% of the vineyard without taking into account weak spots
or high risk entry points – therefore it is “like looking for a needle in a haystack”.)
Samples are collected from the traps every four weeks, and examined by the senior management staff.
This time-consuming task is built into normal working hours and fitted around other jobs (rather than any
extra resources being provided). In the 2009-10 season there were approximately 300 traps being
monitored at the Racecourse and St Hubert’s vineyards. The estimated time taken to collect and examine
samples four times so far from the 250 traps on the St Hubert’s vineyards has been analysed by the
Regional Technical Officer and is estimated at 30 minutes per trap – or 125 hours. (In total they are
sampled five times in a season - once a month from November to March). At an average labour cost of $20
per hour and allowing for the final collection and microscope work this would equate to around $3000 or
$150 per hectare. She noted that the initial set-up is the most time-consuming part, and that the
microscope work is now done comparatively quickly because the people doing it have had a great deal of
experience (this is their fourth year of surveying).
Growers outside the quarantine zone but within the “greater” Yarra Valley are required to have their
properties surveyed by DPI Plant Standards each season (at their own expense) if they wish to send fruit to
a PEZ in Victoria or NSW (this has been the case for some time prior to the phylloxera outbreak and applies
to all PRZ vineyards). This is providing an additional de facto monitoring of the region for outbreaks beyond
the current PIZ boundary. However, it only occurs if a grower has a buyer in a PEZ – as opposed to another
PRZ or PIZ region in Victoria.
There is a formal monitoring program underway at the Coombe Farm property, conducted by Dr Kevin Powell
and his research team as part of a research project funded by GWRDC, DPI Victoria and PGIBSA. The aims of
the research are to compare methods of early detection and determine an optimum protocol for sensitive,
accurate and cost-effective vineyard surveillance. The methods that are being compared are: root surveys,
emergence traps and phylloxera DNA soil probes combined with EM38 and Greenseeker surveys. They are
being evaluated at 500 sample vines on the two own-rooted blocks that are known to be infested. Results
from 2008 have already shown that DNA probes and emergence traps are significantly better than root
surveys (as was previously found at Beavis in 2007). In addition, two other secondary detection methods are
being trialled: EM-38 which measures soil electrical conductivity and Greenseeker which collects imagery of
the canopy from ground level. In each case the images collected are overlaid with the trap and probe results
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to determine whether there is any correlation between presence of phylloxera and soil electrical conductivity
or digitised spectral characteristics of the imagery.
Discussion
The fact that there is no formal, ongoing survey activity in the region means that the industry is relying on
growers to find any further infestations. This may be why only one new infestation has been discovered
since late 2008. The YVWGA Best Practice Guidelines and Protocols for Pest and Disease and Phylloxera
Management for the Yarra Valley advises growers to “monitor vineyards regularly for signs of vine decline”,
but it does not provide guidelines for systematic monitoring by emergence traps or root surveys, where
there may be no canopy symptoms evident. Relying on canopy symptoms is likely to mean that detection is
significantly delayed and leads to lots of “false alarms” particularly in time of drought when vines are
suffering more from stress than usual.
Ideally, the formal survey protocol for delimiting a PIZ used by the Dept of Primary Industries should include
an ongoing monitoring component based on a risk assessment of all patterns of associations in the region of
the outbreak, with a follow-up survey of the whole extent of the associations conducted after one and two
years. This could be expected to find further infestations more quickly than they might be found otherwise
and hence improve the chance of containment within a region as well as giving growers more time to
respond before their vines start to decline.
The use of emergence traps as an alternative to root surveys should also be considered and (preferably) a
formal protocol developed and accepted nationally. The research evidence is already sufficient to confirm
that it is a more sensitive methodology than root surveys. DNA probes may also provide an alternative, but
currently this method is more expensive and not ready for widespread adoption by industry or government.
Both methods have the added advantage that they measure abundance as well as presence, which provides
additional information (although abundance does not necessarily correlate with age of the infestation).
The monitoring being undertaken by Foster’s, Coombe Farm and potentially others (eg Train Trak indicated
that they were intending to establish emergence traps after vintage) is not centrally coordinated, there is no
standard methodology being used and the results are not recorded in any central location. This would seem
to be a waste of an opportunity to study the pattern of infestation and spread effectively and at minimal
cost, because the growers are providing the resources for the work to be done.
Widespread, standardised use of emergence traps by growers on their own properties would be a relatively
inexpensive supplement or alternative to a formal survey program. According to Dr Kevin Powell, to
optimise the chances of detection, emergence traps only need to be put out once – in early January – and
collected four weeks later – thus taking advantage of population peaks and maximising efficiency. Samples
could be combined across the vineyard and sent as a single sample to DPI Victoria Biosciences Research
Division at Rutherglen for analysis as it is not essential to know exactly where the infestation is located in
the vineyard to achieve early detection. A training program could be conducted for growers to ensure the
traps were set up correctly – or a team of trained people could be used and funded at a regional level but
with grower contributions. The process could be implemented fairly easily and cheaply across the PIZ or
even a wider area and would increase certainty for the industry. The ballpark estimated cost of $150 per
hectare, per season, based on Foster’s’ experience, would not seem to be unreasonable. It would be
necessary to determine an appropriate number of traps to be used per hectare to achieve a desired level of
confidence that an infestation was not present. This issue is currently being addressed in the development
of a national PEZ maintenance protocol.
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5. Boundary determinations
First determination
The initial boundary determination was reasonably straightforward. A quarantine zone boundary was
drawn as a circle with a 5km radius from the Beavis property boundaries. This was presented for comment
at the industry meeting in December 2006. As a result of consultation during and after the meeting, an
additional section was added in the north-west portion to include a large processing winery that had most
of its customers – including Beavis – inside the PIZ boundary. The boundary was also mapped to natural
features such as roads and rivers, to make it practical to communicate and adhere to. Approximately
1100ha of vineyard was included in the PIZ. The PIZ was gazetted on 1 March, 2007 (see figure 7 below).
Figure 7 Boundary of original PIZ gazetted in March 2007. Source DPI VIctoria Plant Standards branch
Before the large processing facility could be included, agreement had to be reached with a small number of
vineyards affected by the extension. These negotiations were conducted individually between the vineyard
owners and the DPI Plant Standards Project Officer and took up to three months to finalise. In the end, it is
understood that the winery had to commit to purchase the fruit from the affected vineyards to secure their
agreement.
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Subsequent modifications
The boundary remained unchanged until after the second and subsequent detections in Nov 2008. After
the Racecourse vineyard was found to be infested, the boundary needed as a minimum to be extended
north by approximately 4km – the distance between Beavis and Racecourse vineyards. DPI Plant Standards
drew up a proposed new PIZ using a circle with a radius of 5km centred on Racecourse vineyard,
overlapping the earlier zone so as to maintain the southern and eastern boundaries as per the original PIZ
(see picture).
The Yarra Valley Winegrowers’ Association Committee of Management were not in favour of the proposed
new boundary – partly because of the practical problems it would introduce for wineries and growers
brought into the new zone (just prior to vintage) – and partly because they felt that more phylloxera was
likely to exist in the Valley, which until detected meant a biosecurity risk for industry in other regions and
uncertainty for those within the Yarra Valley but outside the current PIZ boundary (which could change at
any time if there were more detections). The Committee distributed a survey to all its members canvassing
opinion on two options: the minimum expansion proposed by DPI Victoria Plant Standards and the
declaration of the whole of the Yarra Valley as the new PIZ. The results of the survey were 52% in favour of
option 2. A public meeting was then held on 15 December 2008 at which the Committee’s position was
presented fully, and discussion and questions were invited. The survey was repeated in January 2009 and
this time 70% of respondents were in favour of declaring the whole region as a PIZ.
One business to change its mind was Constellation’s Yarra Burn winery – which initially argued strongly in
favour of the smaller zone, and later added its weight to the argument for declaring the whole GI. This
arose as a result of the way in which the boundary consultation process was conducted (and is generally
conducted). Initially, the boundary presented for consultation was roughly circular – being drawn without
regard for natural features. Subsequently, once the principle had been agreed to, the boundary was
adapted to fit to its context: roads, rivers etc. In this case, the translation of the boundary (which is
supposed to be just “tinkering at the edges”) made a material difference to which vineyards were in and
which were out, which in turn affected the business operation of Yarra Burn winery – putting threequarters of their contracted vineyards inside the PIZ. Facing considerable practical difficulties and
increased costs to process their fruit, they had little choice but to argue for what they saw to be the only
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alternative – the declaration of the whole GI as a PIZ, which would bring their winery into the zone along
with most of their contracted fruit.
Another winery – De Bortoli’s – was facing similar difficulties with the original proposed boundary, which
left their winery out but most of their vineyards in the PIZ. Their response was to approach DPI Plant
Standards directly and seek a small modification to the boundary in the northern part that would bring
their winery into the zone – thus allowing them to continue to process their own fruit from within the PIZ.
This request was incorporated into the version of the PIZ that was subsequently presented as option 1
when it was mapped to geographical features. De Bortoli’s were, however, required first to secure the
agreement of the three or four intervening vineyards that would have to be included as well.
Despite the majority vote of the growers after the second survey, DPI Plant Standards did not declare the
whole GI region as a PIZ, because there was not 100% support. Instead, the zone identified by option 1 was
gazetted on 26 February, 2009. The principle that was followed was that a business could not be forced to
be included in a PIZ if there was no technical justification for doing so – i.e. if they were more than 5km
from known infested sites and did not share machinery etc with properties inside the zone.
For vintage 2009, growers in the “new” part of the PIZ were able to get permits to move their fruit out of
the quarantine zone, provided their vineyard was surveyed and found to be free of phylloxera and other
conditions were met: tarped loads, nominated receiving winery close to the vineyard, wash-down and
waste water management requirements etc. This type of arrangement had been in place for vineyards in
the original PIZ for vintage 2007 but was not made available for 2009 – on the grounds that those
growers/wineries had had (by now) plenty of time to adjust to the new requirements and make
arrangements.
Once the rush of vintage was over, some wineries that were located just outside the PIZ boundary (in three
quite different places) put in a joint submission via the YVWGA for the boundary to be modified to include
them. These were Yarra Burn, Giant Steps and Mac Forbes Wines (Gracedale Hills Estate vineyard). It was
only through having seen De Bortoli achieve this result that they thought to make the request, which did
not have a biosecurity basis but a business viability basis. (The Yarra Burn winery is approximately 16km
from Beavis in a straight line and therefore at least 10km outside the minimum 5km radius – resulting in a
very unusual “leg” sticking out in the south-eastern corner of the quarantine zone.) There were only three
growers affected by the proposed extensions, and these were contacted by the wineries directly and
agreed to support the proposal. The new PIZ was gazetted on 24 November 2009 (see fig 8 below).
No special permits for movement of fruit out of the PIZ have been issued for vintage 2010.
At the time of interviewing, some interviewees were under the impression that the boundary issue was still
open, and had been referred to the Victorian Viticulture Biosecurity Committee (VVBC) for review.
However, DPI Plant Standards reported that the VVBC had discussed the boundary issue and had agreed
with the DPI policy that the PIZ should be kept as small as possible in the absence of compelling evidence to
do otherwise. It was noted that the GI region is considerably larger than the minimum PIZ and many
properties could not justifiably be included as they do not have trading links with the infested properties or
other associated properties.
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Figure 8 Second PIZ boundary gazetted in November 2009. Source DPI VIctoria Plant Standards branch.
Discussion
The inclusion of Sticks winery – a major contract processor – in the initial 5km zone was a concession to the
practical business realities for growers and the winery. If this had not happened, approximately 800ha of
vineyards inside the zone would not have had a processor for their fruit, and the contract processor itself
would have lost the vast majority of its customers. The same principle is true of the extensions granted for
De Bortoli, Giant Steps, Mac Forbes Wines and Yarra Burn. The granting of these extensions has eased the
pressure on the industry trying to operate within the current PIZ boundary that divides up the Valley floor;
however, most of the people interviewed for this case study still feel that it was a poor decision not to
declare the whole GI region as a PIZ. Strong words like “insane”, “ludicrous” and “irresponsible” were used.
They believe that the decision has been made because a few (small) growers are able to “hold the
government to ransom” with threats of legal action or bad publicity for the Minister if they were to be
included in the PIZ against their wishes and without “technical justification”. They believe that further
detections in the Valley are virtually a certainty, and therefore that there will be multiple re-drawings of the
boundary with associated disruption and uncertainty for businesses if the whole GI is not declared.
On the other side, the two main arguments for restricting the size of the PIZ are: maintaining market access
for fruit and increased likelihood/rate of phylloxera spread within a larger quarantine zone.
Of the 27 respondents who voted for option 1 in the YVWGA survey, nine made comments indicating that
biosecurity/reduced risk of spread was their reason and five made comments referring to market access
issues.
Some respondents to the YVWGA survey expressed the view that biosecurity protocols would keep
phylloxera restricted but only across the boundary – therefore that extending the boundary would mean
that phylloxera would inevitably spread to the whole GI, and conversely that maintaining the boundary
where it is would protect vineyards outside that zone from becoming infested. One comment made was:
“We will support all of the Yarra Valley GI being declared a PIZ AFTER an enforceable set of biosecurity
controls for internal movement of fruit are fully implemented and legislated.” Another comment was “To
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declare the whole of the YV would be a biosecurity disaster and a declaration of defeat in attempting to
contain phylloxera.”
The assumption underlying this view is that phylloxera will spread more quickly within a quarantine zone
than across a legally enforceable boundary, because within the zone there are no enforceable restrictions on
the movement of risk vectors, and growers must voluntarily practise “farmgate biosecurity” to protect their
property and others’. It would normally be in the grower’s best interests to do everything possible to
prevent or delay the introduction of phylloxera to their property , unless they were already planted on
rootstocks, were not aware of the risks, or simply could not afford to maintain the highest level of
protection. Growers who own a number of vineyards within a quarantine zone would perhaps be less likely
to clean and disinfest machinery, vehicles, footwear etc moving between their own blocks – therefore if one
of their blocks became infested (eg by natural means) then the others would be likely to follow as a result of
movement of risk vectors before the first infestation was detected (as was probably the case with Beavis
and Racecourse). Wineries in the PIZ are required to disinfest bins before sending them out of the zone to
collect fruit; if all their fruit were included in the PIZ they might not continue with this expensive and timeconsuming activity. As one winery noted: “We can’t keep dipping bins forever [within the PIZ]”.
On the other hand, the YVWGA has argued that if the whole GI were a PIZ, then growers and contractors
would be more likely to treat all properties in the zone as potentially infested and therefore enforce strict
protocols for movement of risk vectors consistently, whereas with the smaller zone some growers outside
the boundary do not follow protocols because they believe they are safe, whereas in fact there is a strong
chance that phylloxera is already present in vineyards outside the PIZ boundary. This compromises the
biosecurity of other wine regions as well as local growers. The concern among local industry members that
a vineyard might have an undetected infestation is increased because of the perceived limitations in the
effectiveness of the root survey methodology (see section 4). From the perspective of the SA industry and
the PGIBSA, it would certainly seem to be safer to declare the whole Yarra Valley GI as a PIZ.
Ultimately the containment of phylloxera to the smallest number of vineyards possible depends on the
application of strict biosecurity protocols at the farmgate (and winery) – regardless of where the boundary
is drawn. However, the location of the boundary has significant implications for growers and wineries in
terms of their business operations (see next section). This means that negotiations over the boundary can
be driven by commercial and practical imperatives, rather than biosecurity considerations. It is noted that a
condition of granting the extensions to the PIZ requested by the four large wineries in 2008 and 2009 was
that the wineries themselves obtain the support of the growers affected by the boundary change – whereas
in the 2006 determination the discussions with the growers were conducted by the DPI Plant Standards
Project Officer. Direct negotiations between the growers and the wineries would be affected by their
relationship and balance of power – rather than being objectively based on the best interests of each party
and of the region as a whole.
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6. Effects of the infestation and quarantine restrictions on business operations
The effect of a phylloxera outbreak on a business is different for:
 Growers vs. winemakers
 Businesses inside vs. outside the PIZ
 Vineyards planted on resistant rootstocks vs. ungrafted vines
 Infested vs. uninfested vineyards and the wineries receiving their fruit
Wineries
Wineries that are outside the PIZ with the majority of their fruit inside the zone are significantly affected.
In the case of the Yarra Valley, all wineries interviewed agreed that the worst position for a winery was to
be outside the PIZ with its contracted fruit “locked up” inside. One winery in this situation calculated that
the additional cost of paying for contract processing for their fruit in the PIZ would be around $340,000 per
year. Another considered the option of contract processing to be completely untenable, because the fruit
in question required special handling and specialised winery equipment. The four large wineries most
affected in this way all sought to be included in the PIZ, rather than manage this situation – even though
that meant they needed to install bin dipping facilities at short notice and incur the extra ongoing costs
associated with disinfesting all their bins that had to go out of the PIZ to collect other fruit – as well as
additional handling costs for infested or potentially infested fruit to prevent cross-contamination of other
growers or infestation of their own (adjacent) vineyards. Compliance costs were estimated by one winery
to add 20% to the cost of processing grapes.
Wineries inside the PIZ who mainly process fruit from outside the zone would have incurred the cost of
introducing bin dipping and not gained any personal advantage from being included in the zone. None of
the wineries interviewed expressed that opinion, but a person who was present at the second public
meeting suggested that there appeared to be some resentment about this. It might be expected that any
wineries in that situation would have voted in favour of the whole GI being declared a PIZ – which would
eliminate the need for bin dipping for fruit sourced from the “greater” Yarra Valley region. As it is,
wineries might pay for bin dipping facilities (estimate up to $80,000) and then find that these are no longer
needed if the boundary changes in future (although it should be noted that currently at least two of the
wineries interviewed are dipping all bins during vintage, even when they are only moving inside the PIZ, in
order to minimise the risk of spread).
Case study: Yarra Burn
Yarra Burn winery, owned by Constellation Wines, is situated near the south-western border of the Yarra
Valley GI, and around 16km in a straight line from Beavis vineyard. When the initial outbreak was declared
in 2006, Yarra Burn had most of its fruit outside the 5km zone and sent a large amount of juice into South
Australia. Had the whole GI been declared at that time, it would have had to spend an estimated $850,000
on installing filtration equipment and associated infrastructure to send filtered juice into SA (because of a
long-standing company policy that no unfiltered juice or must would be sent into SA from a known PIZ –
even though this is permitted by the regulations). A bigger problem would have been the lack of time to
put the infrastructure in place, with vintage only eight weeks away when the infestation was discovered.
When the expanded PIZ was declared, Yarra Burn had three-quarters of its contracted fruit inside the zone,
with the winery still outside. This was expected to mean close to $1 million in contract processing costs
over three years. In the event, fire and smoke damage greatly reduced the amount of fruit processed in
2009, and permits were issued for some fruit in the “new” PIZ to move to the winery – thus mitigating the
effect on the business. After the 2009 vintage, the winery sought to be included in the PIZ – despite the
impact on its export of juice to SA. Once again it “dodged a bullet” with surplus filtration equipment from
elsewhere in the company being able to be relocated to the Yarra Valley in plenty of time for vintage 2010.
Another issue for wineries is dealing with fruit from infested vineyards. For example, one winery
interviewed receives fruit from Coombe Farm, which has two infested blocks – each with only a small
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number of vines showing symptoms of decline. The winery has specified that it will not take fruit from the
infested rows themselves, because of the perceived increased risk of bringing crawlers into the winery, and
because of the risk that the quality of the fruit might be affected and would detrimentally affect the rest of
the harvest from that block. This creates logistical difficulties for the grower as well as loss of income, but
in fact the grower indicated that he did not want to pick the infested rows – both to avoid risking quality
and to minimise or slow down spread within the block. Given that it is highly likely that phylloxera is spread
much more widely throughout the vineyard than is apparent from canopy symptoms, both of these
arguments are logically unsustainable.
Another winemaker interviewed did not share this concern over the quality of infested fruit or the potential
for contamination of other vineyards via the winery – because “our systems should be tight enough to
handle an infested vineyard”. (NB they are not currently receiving known infested fruit.) A third said he
would not take infested fruit “regardless of any contractual arrangement” (but once again this has not been
tested as yet). The fruit from Racecourse vineyard was all machine-picked in 2009 and 2010 and sent to
two local wineries for contract processing. The blocks were picked in order of maturity – i.e. no deliberate
attempt was made to reduce spread within the block during picking, or to separate infested from noninfested fruit. The difference in attitude compared with Coombe Farm may reflect the difference in enduse of the fruit.
Growers
Growers inside the PIZ cannot move unprocessed fruit outside the zone. In the YWVGA survey, 8/26
independent growers (i.e. without their own wine label) voted for option 1 (minimum size PIZ) and three of
those cited market access concerns as the reason. Two indicated that they would lose their buyers and one
that they would go out of business if the zone were to include them. A grower who also has a winery but
sells around 50% of his fruit noted when interviewed that he could crush the grapes if necessary to enable
it to move outside the zone as must or juice – but this would have financial implications that either the
grower or the buyer would have to bear. In the case of Foster’s, the fruit from the Racecourse vineyard has
had to be contract processed and filtered within the PIZ before it could be sent to a Foster’s winery
elsewhere in Victoria.
Growers selling their fruit to wineries inside the zone still face uncertainty especially if they have ungrafted
vines, as their winery might be reluctant to sign long-term contracts in case the vines became infested.
Growers outside the PIZ but still in the Yarra Valley are in a PRZ. They are able to sell their fruit elsewhere,
provided their vineyard is surveyed annually (at their expense) and found to be phylloxera free. This was
the case before any phylloxera was detected in the Valley; however, it was suggested by an interviewee
that buyers would now be more reluctant to purchase from these vineyards because of the risk that they
might be infested – especially given the perceived failure of the root surveys to detect early infestations.
Buyers might also be reluctant to sign long-term contracts with growers currently outside the PIZ boundary
because of the risk that another detection would see them included in the zone and their fruit unable to be
exported for processing.
While every purchase arrangement is different, in a time of cool climate grape surpluses in the Australian
wine industry it could be expected that these additional disincentives would reduce the ability of growers in
the Yarra Valley – both inside and outside the PIZ – to sell their fruit.
Growers also may have compliance costs such as heat treatment and certification of machinery if it moves
out of the infested zone.
In addition to business uncertainty, restricted market access and compliance costs, growers face the
additional costs of implementing protocols to protect their vines from becoming infested and (potentially)
replanting their vines in the longer term if they are not already on rootstocks. These aspects are dealt with
in the next two sections.
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7. Implementation of protocols and other protective measures
This section describes some of the measures that have been put in place to reduce the risk of spreading
phylloxera between vineyards, and the practical issues associated with their implementation.
The attitude of most of the people interviewed was that protocols needed to be applied stringently across
the board, to protect their own uninfested vineyards or blocks within the PIZ from becoming infested, to
protect others both inside and outside the zone from becoming infested if they did have an undetected
infestation and to comply with regulations. This message of “farmgate biosecurity” is also the message
promoted by the Yarra Valley Winegrowers’ Association. It is central to their argument that declaring the
whole GI region as a PIZ (option 2) would not increase the rate of spread of phylloxera compared with
keeping it to the minimum required size (option 1). The letter to members accompanying the survey on
preferred options for the PIZ boundary states: “Option 2 is no more of a biosecurity risk than option 1
provided individual vineyards strictly adhere to recommended phylloxera protocols.”
A comprehensive set of protocols based on the National Phylloxera Management Protocol has been
developed by the Yarra Valley Winegrowers’ Association in conjunction with DPI Victoria Plant Standards
and has reportedly now been adopted as a standard across Victoria and taken up by the industry in New
Zealand. The following are examples of the application of these protocols in practice, with any difficulties
or variations highlighted. The descriptions do not necessarily include all the protocols used, nor is any
attempt made to evaluate whether the protocols are being applied sufficiently by any given business.
Vineyard workers and visitors
One grower interviewed described how contractors are required to arrive in clean clothing every day.
Pickers wear disposable coveralls, which are left on the property, and hats are sprayed with insecticide
before the workers start. Semi-regular casuals who work in the vineyard have a pair of dedicated boots
that they leave on site while they are working there and they are required not to work in any other
vineyards during that time. The grower washes the coveralls to increase the amount of use he gets from
them. (“It takes some mucking around but you can do it.”) Wire lifting was considered to be the highest
risk activity because of the close contact with the canopy.
Another grower noted that clothing is much more difficult to disinfest or manage as a risk factor than
boots. Clothing cannot be disinfested if a worker comes onto the vineyard from another property half-way
through the day. This has led to a change in management practices where growers no longer “top up” their
casual staff later in the day with a team from another property that has finished early. This reduces
flexibility for the growers in managing their vineyards – especially during harvest. There is also the problem
of workers who arrive late and go directly to the paddock to join the rest of the team, bypassing footbaths
and other biosecurity measures that were set up at the start of the shift. Non-English-speaking casual
labourers and experienced workers from other countries where phylloxera is ignored can be particularly
unaware of the need to adopt biosecurity measures.
Another issue raised was the difficulty in getting contract workers to stand in the footbath to disinfest their
boots for the full 30 seconds. As a “solution”, an example was reported of a grower using three sequential
footbaths and requiring workers to stand in each for 10 seconds as a way to improve compliance.
The Foster’s Regional Technical Officer for Victoria is required to visit all company owned vineyards in the
Yarra Valley, including the infested Racecourse and the high risk St Hubert’s vineyards. Her practice is to
have three separate pairs of boots – for each of Racecourse, St Hubert’s and the other three. She also has a
complete change of clothes and wears coveralls when visiting Racecourse or St Hubert’s – then changes
clothes and sprays and bags the clothes before getting in her car to prevent later re-infestation via the car.
The clothes are hot washed before being reused. Winemakers visiting these vineyards are expected to
follow the same procedure – as well as visiting the vineyards in a set sequence from the least to the most
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likely to be infested. It was noted that ideally there needs to be a local person on hand during winemakers’
visits to provide coveralls and set up footbaths, to minimise downtime.
Vineyard machinery
Machinery is required to be steam cleaned or heat treated to move out of the PIZ (for harvesters the heat
treatment is compulsory). As discussed above, many growers inside and outside the zone have adopted a
farmgate approach to biosecurity – therefore they either require machinery to be heat treated before
coming onto their property or have their own dedicated machinery. This policy is facilitated by the
relatively large number of heat sheds that have been installed within the PIZ, which give growers and
contractors reasonably easy and affordable access to this disinfestation treatment. Foster’s charges
$240+GST for the use of their heat shed. One grower estimated that the cost of heat treating machinery
added up to $5000 per year over 135 acres – or roughly $10 per tonne. The big cost is the downtime
incurred, as the treatment itself takes at least an hour and a half – plus heating up and cooling down time –
and the equipment needs to be cleaned beforehand and driven to and from the heat shed.
One grower with multiple vineyards noted that it is not practical to have a central wash-down facility,
because there is too much travelling time – especially with tractors that can only travel very slowly on
roads. Therefore facilities have been installed at each vineyard at an estimated cost of $10,000 (including
earthworks). The wash-down water passes through a silt trap then a triple interceptor to remove solids
and oils, grease etc. It does not drain to the vineyard. The solid waste is carted to the compost pile at the
rear of the property. It was noted that water management is a significant issue, as wash-downs consume a
substantial amount of water, none of which can be re-used on the vineyards in case it contains phylloxera.
Another grower reported that no machinery comes onto his property any more. He has moved from
machine harvesting to hand picking – paying $200-$300 per tonne instead of $50-$70 per tonne. Even
adding heat treatment costs to the machine harvesting option, this represents an extra $35,000 or nearly
tripling of his harvesting costs.
Vineyard security
Fences and locked gates are central to protecting vineyards by restricting access to unauthorised visitors.
However, there are many practical issues that can get in the way of simply implementing this protocol.
Train Trak vineyard is adjacent to the infested Racecourse vineyard. Central to their farmgate biosecurity
policy is the use of locked gates and signs to restrict access (fig 9). This was made possible, however,
because the 14 hectare property was already fully fenced with approximately 5km of secure farm fencing –
as it had previously been a horse stud. The costs associated with putting up such fencing if it had not
already existed would have been around $70,000 – a prohibitive cost. The vineyard manager noted: “It’s
not so scary if you have some infrastructure in place – but if you have nothing..........”
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Figure 9 Locked gate and signage at Train Trak vineyard. Source: PGIBSA.
A large winery with surrounding vineyards put up simple chain link fencing all around the vineyards near
the cellar door and restaurant complex (see figure 10 below). This fence would not actually prevent
someone from accessing the vines, but could be expected to act as a deterrent to the general public –
without spoiling the look of the vineyard or costing too much. It therefore represents something of a
compromise between biosecurity and practicality.
Another grower interviewed said he was intending to move the driveway that leads up to his cellar door,
which currently runs alongside his vineyard. He had decided to do so rather than put up a fence between
the vineyard and the driveway because this would not give him room to turn his tractor.
FIgure 10 Simple post and chain fencing at major tourist winery vineyard. Source PGIBSA.
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Bin dipping
One of the first steps taken by wineries when the PIZ was declared in 2007 was the installation of bin
dipping facilities, to enable them to send bins out of the quarantine zone to collect their fruit from the PRZ.
The bin dippers were installed somewhat hastily, given the lack of time before vintage for proper planning.
The winemakers interviewed noted design flaws with the bin dippers. One winemaker described them as
“potentially very dangerous with a huge energy requirement”. They also require a large amount of water,
which is a scarce resource. One winemaker questioned the requirement (regulation) to dip bins that are
received into the winery from a PEZ, are emptied at the winery, do not contact the ground and are then
returned to the PEZ empty. Another questioned the basis for the specification of 70˚C for 2 minutes and
noted that it would make a big difference to their throughput if the time requirement could be reduced.
Prior to being dipped, the bins need to be cleaned, which requires a large amount of water – usually
delivered by high pressure hot water cleaners. While there is no regulation to contain or treat waste water
within the PIZ, wineries that are concerned about not infesting their own vineyards near the winery choose
to divert the waste water to settling ponds or closed sewerage systems rather than sending them directly
to vineyards or even adjacent wood lots.
Case study: Yering Station
Yering Station is a medium-sized (2000t) privately owned winery located roughly half-way between Beavis
and Racecourse. It has seven vineyards totalling 250 hectares including 120ha of estate vineyards less than
1km from the original detection site. Over 90% of the vineyards are planted on their own roots. The
winery has been included in the PIZ since the original detection. Approximately two thirds of their growers
are inside the PIZ and the remaining one third are outside. Yering Station has implemented stringent
protocols at its winery and between its vineyards because “if we have it we don’t want to spread it or if we
don’t have it we don’t want to get it”.
All picking bins are disinfested in hot water (“dipped”) at 70°C for 2 minutes. This has meant establishing a
bunded staging area, having a second forklift and employing two extra people. The bin dipper (“yabbie
pot”) cost an estimated $80,000. The winery is also required to be accredited by DPI Plant Standards to
inspect and certify their own bins – thus saving the cost and inconvenience of having an inspector issue a
certificate for each bin leaving the winery destined for a PRZ. An annual audit of the winery’s systems is a
requirement of this accreditation. Buckets and snips are also dipped, using a bucket cage.
Prior to dipping, all bins are cleaned with high pressure hot water. During vintage, it is estimated that two
of these cleaners work continuously for 8 – 9 hours per day, which means they consume approximately
320,000 litres of water in total. The waste water is all captured and goes into the main sewer.
The problems with the bin dipping process are perceived to be the downtime waiting for treatment during
peak times – which creates a bottleneck in the grape processing system, the large amount of water used for
cleaning the bins and the inconvenience of running out of gas. The comment was made that the bin dipper
is not a good design – possibly as a result of the need to install it in a hurry after the first outbreak, when
vintage was imminent. Any residue left in the water from the bins sticks to the screens on the heaters
which in turn causes a loss of temperature.
All vineyard equipment is also disinfested if it moves between the company’s vineyards. A heat shed was
built at the winery’s Spring Lane vineyard at an estimated cost of $50,000. To clean and heat treat a
harvester is estimated to take approximately 40 hours and requires trained mechanics to perform properly.
This impacts on harvesting and potentially on quality, because particular blocks cannot necessarily be
picked exactly when or in the order desired by the winemaker.
Overall it is estimated by Yering Station that the implementation of disinfestation protocols adds 20% to
their cost of growing grapes.
Other means of reducing risk of spread
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One grower whose vineyard is infested has modified his work practices to attempt to slow the spread
through the block and to the rest of the property. The block is systematically worked from the point
furthest from the infested rows, in towards the infested section. With manual work, only one worker goes
into the section where the infestation has been found – then disinfests his/her boots straight away.
Machinery is steam cleaned and heat treated after working in that section before going to any other block.
The infested block is always worked last of the eight blocks on the 60 hectare property. A heat shed has
been built on the property (cost approximately $30,000) and a steam cleaner installed (approximately
$4,500).
A couple of issues were raised about other possible means of infestation that are not covered by protocols.
For example, it was suggested that the Yarra Glen township could be a potential hub for crosscontamination via vineyard vehicles and workers who convene in the township for shopping, socialising,
eating etc – especially when conditions are muddy. The town is less than 3km inside the PIZ boundary on
the western side. Similarly, Healesville is approximately 3km outside the boundary on the eastern side.
The two towns would each be expected to serve a mix of growers, vineyard and winery workers, tourists,
vehicles and machinery from both inside and outside the PIZ.
Another issue raised was the Grape Grazing festival. This is traditionally a wine and food event held in the
Valley that involves tourists visiting a number of wineries. One grower indicated that he felt this was a high
risk activity because “people get lost among the vines” but that it had now been cancelled because it was
too high risk (for spreading phylloxera). However, the YVWGA reports that the Grape Grazing festival was
actually postponed in 2009 because of the fires, and is now being re-evaluated because of the association
with the bushfire season and some undesirable behaviour that had increasingly been occurring – not
because of the phylloxera outbreak. It is expected to resume later this year or next year. There is no
indication on the Grape Grazing website that tourists are encouraged to walk into the vineyards or taste
grapes on the vines.
Discussion
While there is a standard best practice protocol available, the implementation of protocols is not consistent.
Existing infrastructure and management practices, as well as a grower’s personal beliefs, knowledge,
perception of risk and what he/she has at stake affect how each business is able to respond.
Cost and safety are elements that modulate the application of protocols. In the case of proper, secure
fencing, cost is probably the biggest deterrent for most growers – or at least an informal cost-benefit
assessment of the likely reduction in risk that would be achieved – compared with controlling machinery,
workers and authorised visitors on the property. For the wineries and vineyard owners interviewed, the
installation of high-capital items like bin dippers and heat sheds did not seem to be a major concern; rather
the issue was with the downtime and scheduling difficulties arising from having to use the equipment. One
grower, who had installed his own heat shed, had initially implemented heat treatment between each of his
blocks but has since reduced the requirement to treatment only after working in infested blocks – because
“you must still complete operations in a timely manner”. This is particularly true at vintage time. The
ongoing costs of bleach, gas, disposable overalls etc are very minimal compared with time costs – most of
which were not quantified. In the case of the Foster’s Regional Technical Officer, the time involved in
disinfesting between properties is absorbed into her work time, and is not believed to have a significant
impact (“it only takes around 5 minutes” in a day). In the case of Train Trak, phylloxera management is
estimated to account for around 1 – 2 hours per week of the contract vineyard manager’s time. She
described protocols as “more inconvenient than expensive” (although as she is a paid consultant, there
would be a direct cost of this implementation to the vineyard owner).
Safety was raised as an issue by a winemaker, who suggested that the bin dippers with their tub of water at
70°C were potentially very dangerous, especially over a season where they might dip over 2000 bins, which
occasionally slip from the forklift back into the hot water. It was suggested that smaller wineries would be
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better off using shipping containers and dry heat instead, if they did not have the time pressure on them to
send the bins out again straight away (dry heat treatment takes substantially longer, but equipment could
be left overnight if not required). Concerns have been raised previously with the National Phylloxera
Technical Reference Group regarding the safety of handling chlorine as part of the footwear disinfestation
protocol – particularly when people are required to carry containers of it from place to place in their
vehicles.
There are also potential issues with the design and supply of equipment and facilities - such as the heat
sheds and bin dippers. It was noted that the 2009 vintage bin dippers were installed in haste, and that
already design improvements have been made by a winery that had the opportunity to learn from the
experiences of the others before installing theirs. It is not clear whether any future customers would have
access to these design improvements if they did not happen to talk to the other winemakers. It was also
pointed out by a winemaker that the only place that he knew of where the bin dippers were made is
Wodonga. This would be a serious problem if an outbreak were detected in a South Australian region just
prior to vintage.
There does not seem to be any standard design for heat sheds, either, although no-one reported any
problems either with building or running and maintaining them.
The fact that the protocols are voluntary will always lead to variation in their application. The comment
was made that most growers were “locking down” their properties, but that the few that don’t – especially
absentee owners, lifestyle grapegrowers etc with no knowledge of viticulture – were “risking everyone”. A
common theme that emerged in the interviews was a desire that the protocols be enforced within the PIZ –
and/or at least for risk vectors exiting infested properties. (Once a PIZ is declared, there are no stricter
regulatory controls on the infested property than on any other property within the quarantine zone.)
Foster’s took a proactive approach and voluntarily maintained a very strict lock-down on Beavis vineyard
(after the initial quarantine restrictions on the property imposed by DPI Plant Standards were lifted) and
later on Racecourse – with locked gates, allocated vehicles, dedicated or heat treated machinery, separate
parking, separate shoes etc. The fact that no further detections have been made on other Foster’s vineyards
to date may indicate that this strict approach has prevented further spread – or at least slowed it down. If a
similar approach could be regulated for all infested vineyards – or better still all vineyards within the PIZ
because of the high risk of an undetected infestation – then it is likely that across the board and over time
the rate of spread would be reduced.
South Australia could potentially introduce this level of control within a quarantine zone, as the Minister has
the power within the regulations of the Plant Health Act to
require the owners or occupiers of premises within the quarantine area to take measures (including the
destruction of plants and plant related products), specified in the notice, that are, in the opinion of the
Minister, necessary for the control or eradication of a pest.
However, there would be practical difficulties such as the costs to industry of complying and the government
resources required to monitor compliance. It would be worth investigating beforehand the feasibility of
introducing any measures along these lines in a South Australian situation.
Natural spread
Train Trak vineyard is next door to Racecourse vineyard on the eastern side. As a attempt to reduce the
chance of natural spread between the vineyards, the owners of each property have pulled out the two
closest rows to create a four row buffer (plus headland and treeline) between the blocks – approximately
30m (fig 11). There is also a solid fence between the properties. The originally infested section of
Racecourse is on the far side of the block from the Train Trak boundary (although the infestation has now
spread to most blocks).
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Figure 11 Buffer created between Train Trak and Racecourse vineyards. Source PGIBSA.
Discussion
According to Dr Kevin Powell, there is some (but limited) experimental evidence that crawlers can be windblown up to 20m – 30m maximum. Therefore there is some rationale for a buffer of at least that width
(although preferably more, as the crawlers could presumably travel some distance on the ground as well).
However, this assumes that the vineyard was not already infested at the time the buffer was created, that
all movement of human-assisted vectors has been eliminated, and that there is no more than a slim chance
of animal or bird-assisted spread (otherwise it would be a pointless exercise). Hardie and Whiting (2007)
have argued that birds and animals can theoretically carry phylloxera (“spread by this means is suspected
but unconfirmed”). If birds can pick up crawlers from the canopy in the Racecourse vineyard they could
transfer them to the Train Trak vineyard within a few minutes. The tree line between the properties may be
a source of refuge for birds, from which they might fly to and fro between the two vineyards.
The decision to create this buffer was taken by the two vineyard owners in consultation, but not based on
any standard wisdom or expert advice. It was suggested by the Train Trak vineyard manager that it would
be very helpful to have a set of guidelines available for the neighbours of newly detected infested vineyards
to consider.
As part of developing such guidelines, it would be worthwhile to examine the evidence related to the
effectiveness of buffers in preventing non-human-assisted spread of phylloxera.
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8. Progress of phylloxera infestation and replanting plans
Progress of infestation
Since the first detection in late 2006, phylloxera has been found in four other vineyards – three
neighbouring the first and one on a property with common ownership. From December 2008 until March
2010 no more properties were found to be infested. On March 18, 2010 Chandon Australia announced that
phylloxera had been found on its Yarra Valley vineyard - which was confirmed by Dr Powell. It is not
certain that the original source has been found – although if there is another, older infestation than one of
those already detected, then it is now at least four years old and would be expected to be showing canopy
signs (unless it is in a block of grafted vines or has unusual soil conditions minimising the damage to the
vine roots).
The infestations in the Racecourse and Coombe Farm vineyards are spreading rapidly within the vineyard,
and vine decline is also rapid. On Coombe Farm there is estimated to have been a 10-fold increase in the
number of vines showing symptoms of decline in the past 12-15 months (from three vines to 30 vines since
October 2008 – despite the grower’s best efforts to reduce any human-assisted spread within the block).
75% of the symptomatic vines have greatly reduced yield. The winemaker from Yering Station described
the rate of decline as “scary – this is the most virulent phylloxera I’ve ever seen”, with the vines going from
showing no symptoms at all to being virtually unproductive in one season. The Coombe Farm vineyard
manager made the comment: “This genotype seems to really like the conditions at Coombe Farm”.
A similar pattern was evident at Beavis before the vines were removed. The vineyard manager there
described the rate of decline as much faster than he had expected – predicting that they would have had to
replant the whole 32 hectare block within five years, if they had not decided to remove the vines. At
Racecourse the story is the same: very rapid decline in the part of the vineyard where the galls were first
found and a dramatic increase in the infested area over 12 months. Unlike the text-book “oil spot” pattern,
the symptoms at Racecourse are spreading in a cigar-shaped pattern in a north-easterly direction – up the
rows and in the direction of the prevailing south-westerly winds7 (see fig 12). In the 14 months since
phylloxera was first detected in the vineyard, it has now spread to most blocks in the 29ha, own-rooted
vineyard. Despite this, paradoxically vintage 2010 actually produced a bigger crop on Racecourse than
2009, due to the more favourable conditions – particularly higher rainfall and more water available for
irrigation.
7
Although not necessarily as a result of these. An alternative possibility is soil variation, which has not been mapped.
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Figure
12
Image
shows
Racecourse property with original detection site in red and spread pattern outlined in yellow. Green area indicated where
emergence traps have been placed but no insects have been found as at March 2010.
Source: B Collins, Foster's Wine Estates.
Discussion
The difference between spread and decline is an important concept. Where phylloxera is observed to spread
in the vineyard, this is usually because canopy symptoms are apparent – therefore what is actually being
observed is rate of decline. Spread is determined primarily by soil type, soil chemistry, movement of vectors
and climatic conditions. Dr Kevin Powell has noted that spread may be reduced by hot and dry conditions
(because the phylloxera crawlers are less likely to move above ground and reproduction and development
may also be affected) and may be increased in cooler conditions. Conversely, decline tends to be more
apparent in (and accelerated by) hot dry conditions where the vines are stressed. Therefore, in the 2009-10
season, which has been cooler and wetter than 2008-09, phylloxera may be spreading rapidly above and
below ground but not producing associated symptoms of decline. If this is taking place in vineyards not
known to be infested, then the risk of it being inadvertently spread to other properties is increased – even if
farmgate biosecurity is being practised. This emphasises the need for monitoring with emergence traps or
root surveys, not relying on canopy observations, for early detection.
By the time canopy symptoms are observed, it is likely that phylloxera will have been present for a few
years, and that (on own roots) decline will start to speed up exponentially, according to Kevin Powell (“once
you find it, things *typically+ go down very rapidly”). What is not known is how much of the rapid decline
observed in the infested vineyards in this region is attributable to the genotype and predominant soil type of
the region, and how much to the dry conditions that have prevailed over the past few years. If the latter –
then future decline could perhaps be slower than the pattern to date, if higher rainfall persists as has been
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the case this spring. Results of recent research (Herbert et al 2010) indicate, however, that G1 and G4 are
very aggressive on V. vinifera, which would suggest that the former scenario is more likely.
Rootstocks and replanting
Across the Yarra Valley it is estimated that less than 20% of vines are planted on rootstocks. Within the
small sample of vineyard owners/managers interviewed, six out of eight reported having all their vineyards
on own roots, one had 65% on rootstocks and one had 73% on rootstocks. Reasons for planting on
rootstocks were mainly related to phylloxera:
 “We have a vineyard in the King Valley which prompted our decision to plant the Yarra Valley
vineyards on rootstocks”;
 “We were advised to plant on rootstocks [10 years ago] in case phylloxera came one day”.
Reasons for not planting on rootstocks included availability of material, cost and perceived lack of need.
Anecdotally, the most commonly used rootstocks in the Yarra Valley are considered to be:
 101-14
 Schwarzmann
 1103 Paulsen
 5C Teleki
Case study: Coombe Farm
Coombe Farm has a total of 60 hectares planted in 1999. 73% of the vines were planted on rootstocks on
the advice of a viticultural consulting firm – in case phylloxera ever infested the region. The remaining 27%
were only left on their own roots because it was not possible to get grafted material for the desired clones.
The three ungrafted blocks are Block A (Chardonnay – Mendoza clone), Block B (Marsanne and Arneis) and
Block D (Chardonnay – P58 clone). Block G also has some ungrafted Pinot Noir. Blocks A and D face St
Hubert’s Road – more or less directly opposite the Beavis block and right next to the St Hubert’s vineyard
(with which it shares two boundaries). They are infested with phylloxera. Block B was removed in winter
2009 despite not apparently being infested. This was done “to minimise the risk of phylloxera moving” and
also because there was no requirement for the fruit, so this was an opportunity to replant with the
Mendoza Chardonnay clone before all the existing (high demand) fruit of that variety in Block A was lost.
The vines were removed using a 2-tonne excavator, which pulls out the vines by the roots with minimal
disturbance to the rest of the soil. The vines were burnt on the property.
Block B was replanted in December 2009. The rootstock chosen was 99 Richter, which the vineyard
manager hopes will prove to be a good rootstock for the Yarra Valley based on his research. 101-14 has
traditionally been used in this region and is the predominant rootstock on Coombe Farm along with
Schwarzmann; however, the manager considers that the 101-14 is too devigorating and does not suit the
changed (drier) climate.
Of the 60 hectares, Coombe Farm will only need to replant around 16 hectares. However, “tough
decisions” still have to be made because the best Chardonnay is from the infested block and the fruit from
the other blocks will not make up for its loss. If 101-14 proves unable to perform in the current and future
conditions, then those blocks may also need to be replanted in time. A replanting plan has not yet been
prepared, because of the time pressures leading up to vintage. The manager hopes to have one in place by
autumn. His experience is that grafted material can be ordered in April and will be available for planting in
the spring of the same year.
Of the eight vineyard owners interviewed, only one had already developed a replanting plan. Two intended
preparing a plan and mentioned vintage pressures as preventing them from doing it sooner and a fourth
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said he would not replant if his vines became infested (“I’m too old to replant”). Another vineyard was
already on the market before it became infested, so there are no plans to replant it prior to sale.
Replanting activities so far have to some extent been driven by opportunistic factors - eg Coombe Farm
have replanted a block (uninfested) that was not profitable anyway and Yering Station are using a block
that was burnt out in the 2009 fire to conduct one rootstock trial and pulling out a block of very young
Shiraz to conduct another one – because the vines are not yet established so there is less to lose. Another
grower indicated that their replant program would probably be driven by brand requirements and they
would perhaps start replanting in 2011 or 2012 if they wanted a variety change – ie it was a “business
decision with an extra incentive due to phylloxera”. However, it was also noted that the current industry
situation is not helping, as many vineyards are struggling financially already and would find it difficult to
raise the finances required for replanting.
Foster’s has drafted a 20 year replanting plan for their St Hubert’s vineyard. Their selection of rootstocks
was made using the Yalumba rootstock selector and speaking to the Yalumba nursery viticulturist. A total
of six different stocks have been chosen, with one or two selections only per variety. Vigour and drought
resistance have been the main considerations aside from phylloxera resistance. The rootstocks chosen are:
110 Richter and 99 Richter, 1103 Paulsen, 140 Ruggeri, 101-14 and Schwarzmann.
Both Foster’s and Train Trak mentioned that it would be beneficial to start restructuring as soon as
possible, to replace unprofitable blocks, but that it is difficult to justify the expense within current business
plans, when the block in question is not actually infested.
De Bortoli’s vineyards have the majority planted on rootstocks already. Apart from withstanding
phylloxera, rootstocks are also considered important to help control vigour and water use. 101-14 was
mentioned as being normally the most important rootstock, but not during a drought situation. Ongoing
trials are being conducted and evaluated to determine which rootstocks are best. It is felt that rootstock
selection needs to be based on site specific trials.
Yering Station has prepared a plan for a rootstock trial consisting of five rootstocks on each of MV6 Pinot
Noir and Shiraz. The five rootstocks chosen are: Borner, 5C Teleki, 1103 Paulsen, 3309C and 101-14. These
were also chosen on the advice of the Yalumba nursery viticulturist, with general guidance offered by the
PGIBSA Rootstock Project Manager.
It was commented by one winemaker that when Oregon was replanted after becoming infested with
phylloxera, three different rootstocks were used, and no differences could ever be detected in the resultant
wines. His message for rootstock selection was: “Don’t worry about wine quality – worry about vine
health.”
Discussion
It is apparent from the interviews conducted that the response to the phylloxera outbreak in terms of
replanting vineyards is occurring slowly. Although the interviews did not take in a broad spectrum of
growers in the Valley, they did include those closest to and most affected by the outbreak, and it could
reasonably be assumed that other growers further away from the infested properties are likely to be even
less far down the track of preparing to replant their vineyards. It was commented by a committee member
of the YVWGA that the difference in the mood and reaction of the growers between the first industry
meeting in 2006 and the second one in 2008 was because they had realised that phylloxera was “not going
to race through a vineyard let alone the whole area” and they were no longer panicking but taking a
“pragmatic and rational” approach to the way forward – including seeing the business opportunity in a
restructure program – even if they would not have chosen to have it forced upon them.
Based on the experience at Coombe Farm, Racecourse and Beavis, however, it could be that waiting for
visual symptoms to signal the presence of phylloxera will lead to growers having very little time to respond
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and replant. As noted in the previous discussion section, decline can be very rapid once visual symptoms
appear, which means that growers should at least be prepared in advance – in terms of a budget, a
replanting plan and preferably some results from a small-scale trial – otherwise they may have a very short
timeframe in which to plan, budget for and complete a replanting program before their vineyard becomes
completely unproductive. Calculations done by the PGIBSA have shown that for a typical 10ha block, even
replanted at a rate of 1ha per year over 10 years, starting five years after the initial detection, the
cumulative loss of income over the first 12 years is around $75,000, with the maximum loss being $50,000 in
one year.
Ironically, while the current business climate would seem to provide an additional incentive to start
replanting and hence remove non-profitable varieties, it may be that those varieties are not the most likely
to be infested with phylloxera. For example, at Train Trak the first variety to be targeted from a business
restructuring point of view would be a non-profitable block some distance from Racecourse, whereas the
block at greatest risk of being infested(based on proximity) is a more profitable variety that they would not
wish to replace for any reason other than phylloxera. Also – as noted above – a time of economic difficulty
is not necessarily conducive to a costly restructuring program.
Choice of rootstocks seems to be driven by individual opinions and strategies. The PGIBSA was approached
for advice regarding the Yering Station rootstock trial and offered some assistance, on the proviso of the
trial being established so as to be scientifically robust and the results being made available to the Yarra
Valley grower community. The YVWGA were approached to be a joint partner, and the proposal was
submitted to the GWRDC for funding, but it was not supported. Therefore it appears as though it will go
ahead without regional or funding support and the results will presumably be kept in-house.
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9. Expected long term effects on the region
One of the major concerns of the industry in South Australia is that a phylloxera outbreak would have a
devastating impact on a region as well as on individual vineyards. This may be through a combination of
reduced income to the region, loss of products with a regional label, downsizing of the industry leading to
loss of jobs etc and negative publicity leading to reduced tourism.
The view of the people interviewed for this case study was consistently that there would be no long-term
detrimental effect to the region (“look at Marlborough”). A theme was that this would be a “good
opportunity to improve the varietal mix and address oversupply” and that the region would end up better
off – although “you would prefer not to have it forced on you”. One person described living through
finding phylloxera in Oregon – where they took the opportunity to change the planting density and use a
devigorating rootstock and better clones, thus ending up with vineyards that were better suited to the
growing conditions. The massive expansion of vineyards in the mid-1990s in the Yarra Valley was driven
mainly by consumer demand – rather than selecting the best vine for a particular site, and this could now
be redressed. New plantings on rootstocks can also address current viticultural issues such as salt and
drought.
As for any impact on tourism, it was commented that most tourists “don’t know or care” about phylloxera,
and the outbreak is not believed to have had any effect on tourism (although the fires have had a
substantial effect at least in the short term). It was suggested that outside the industry the outbreak was
not even newsworthy; words like “disaster” and “catastrophic” did not make sense, because there were no
visible signs of any problem: “all the signals around you are positive – lots of grapes on vines, lovely wines
etc.”
Within the small sample of people interviewed, there was no mention of the additional costs of protocols
and replanting as being likely to cause their business to go under. “Phylloxera is just another thing we have
to manage, and not a deadly scourge.”
Discussion
It is clearly too early to assess the long-term impact of the arrival of phylloxera on the Yarra Valley.
Experience in other regions in Australia and overseas regions such as Oregon and Marlborough suggests a
positive outcome in the longer term for the region as a whole, but there may be many individual stories of
extreme hardship along the way. However, it is probably the case that phylloxera by itself would not
normally be sufficient to cause a business to fail – but it could be the “final straw” in a context of industry
oversupply where 20% of vineyards across Australia are believed to be surplus to requirements.
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Summary and recommendations
Summary of findings
The main findings from the case study were:

Given the right conditions, phylloxera can cause very rapid decline – with some examples of vines
going from showing no symptoms to being virtually unproductive within 12 months.

Eradication using the method applied in the Yarra Valley was not successful – even in a case of
relatively early detection, well considered methodology and substantial resource allocation.

In pilot studies conducted so far in the region, emergence traps were found to be better than root
surveys for detecting phylloxera. DNA soil probes were also better. Both alternative methods can
measure abundance as well as presence, and have found phylloxera where no canopy symptoms
were present.

It is very difficult to determine the source of an outbreak – even when record-keeping has been
very thorough and risk vectors kept to a minimum. This is particularly true with a widely
distributed genotype such as G1.

Growers’ initial reaction can be highly emotional and confrontational – despite generally known
experiences in Australia and other countries with phylloxera – and this makes communicating
information about management difficult.

Boundary determinations have been subject to political pressures and practical issues – not just
biosecurity considerations. Differences in opinion about boundary location are divisive within the
industry – particularly where the process of determination is felt to be unfair.

Wineries would generally prefer to be inside a PIZ than outside it (if their fruit is inside) because the
costs and inconvenience of having fruit processed before it can enter the winery outweigh the costs
and inconvenience of implementing protocols to bring fruit in from outside the PIZ.

Concessions in the application of regulations have been made to allow market access – which
appears to compromise biosecurity; however, without these concessions, businesses would be
unable to operate.

The implementation of protocols is not consistent across the PIZ or the wider region because of
individual differences between growers in attitude, experience, resources available etc

Replanting is not being treated as an urgent priority – probably because the phylloxera appears to
be spreading very slowly between properties;

For most of the industry, after the initial shock the impact of the phylloxera outbreak so far seems
to have been very small or not measurable in a day-to-day context. Vintage, drought, bushfires and
markets are more pressing issues for growers to deal with.
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Recommendations
Based on the findings from the case study, a total of 20 recommendations have been made for actions the
PGIBSA can take to mitigate the effects of a future outbreak in a South Australian grapegrowing region.
These are summarised below. However, it should be noted that every outbreak is likely to be different and
some of the conclusions underpinning the recommendations will not apply in a different outbreak scenario.
Additions to PGIBSA contingency management plan for phylloxera
1. Include more opportunities in different formats for growers to receive information and ask
questions after a phylloxera outbreak.
2. Develop and incorporate a clear policy for quarantine zone boundary determination – including
grounds for determination, policy and process for granting extensions and role of industry
consultation.
3. Include a mechanism for facilitating the sharing of information on rootstock selection and
assistance with the implementation of replanting plans; and a requirement that phylloxera
samples from all infested properties by genotyped.
4. Investigate the feasibility of adopting a policy in the contingency management plan that would
enforce the use of certain protocols within a PIZ in SA.
Additions to protocols
5. Prepare a summary worksheet relating vineyard protection protocols to risk assessment
information, to enable growers to prioritise the implementation of protocols and maximise their
return on resource expenditure in terms of risk reduction.
6. Promote record-keeping on vineyards for visitors and machinery and provide a facility on the
new vineyard register for growers to download standardised visitor logs.
7. Develop a protocol for vineyard monitoring for phylloxera by growers and provide a facility on
the new vineyard register for growers to record the results of their surveillance activities (in the
event of an outbreak in a region in SA or as part of an area freedom maintenance program).
8. Develop a comprehensive protocol for replanting in an infested region – including timing relative
to the first detection, considerations in rootstock selection, cost modelling and the incorporation
of a small trial of standardised design. Incorporate best practice guidelines for the efficient, costeffective and safe removal of the infested vines.
9. Document a detailed, best practice protocol for the eradication of phylloxera from a limited site.
10. Develop guidelines for neighbours of infested properties – to be used in the event of an outbreak
in SA.
Research projects
11. Support the accelerated development of a practical, cost-effective protocol for the use of DNA
soil probes to confirm the presence (or absence) of phylloxera.
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12. Fund an evaluation of the effectiveness of the eradication attempt at Beavis vineyard – using
DNA soil probes to determine how long it takes for there to be no live phylloxera present in the
soil.
13. Commission a review of the evidence that a buffer zone between a phylloxera infested and an
uninfested vineyard can reduce the risk of non human-assisted spread of phylloxera – and a
recommendation for the minimum buffer width if appropriate.
14. Fund a project to develop a practical design for bin disinfestation facilities for both large and
small winery operations (eg as a project for University engineering students) including the
investigation of the use of steam or dry heat rather than hot water.
15. Prepare a comparison of different heat shed designs – based on those built in the Yarra Valley
and elsewhere in Victoria – in terms of construction cost, running costs and other variables – and
document the specifications for each recommended design in a format that can be made
available to industry.
Policy development
16. Facilitate the development of an emergence traps methodology to add to the nationally
endorsed protocol for vineyard surveillance.
17. Develop a protocol for surveillance of infested areas in SA based on the (new) national protocol
and incorporating annual repeat surveys and a grower monitoring component.
Communication / education
18. Examine all educational/promotional material and ensure that messages related to the
consequences of a phylloxera infestation are practical and proportionate.
19. Write an article for an industry journal describing the attempted eradication at Beavis and its
outcome.
Other
20. Revisit and update this case study report in two years’ time.
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