<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>I have a problem which I suspect may be related to Verticillium Wilt (as I
have run out of other options).

A grove I have just taken over the maintenance of has a number of 2 to 3
year old Frantoio (and other) trees which have serious die-back problems.
The trees have reached about one and a half meters, then started to die back
from the top down. There is dead wood extending down to about half a meter
from the base in many cases, but side shoots seem for the most part un
affected, unless the die-back has reached the join.

Several of the trees have re-suckered from the base and I am encouraging
this new growth at the expense of the dead section, which I have cut back to
healthy timber. They did take a caning from both olive lace bug and peacock
spot (by the looks for things) but I don't know if this is the only reason
for the die-back, as I really can't see the pattern of damage being
consistent with the usual damage caused by OLB & PS.

The soil is a lovely sandy loam, which in some spots is quite shallow, but
for the most part is at least 500mm deep. The roots seem to have no problem
penetrating the soil and seem quite healthy on first inspection, if a little
brittle. The soil seems to retain more moisture that I would expect from
sandy loam, but there is no visual evidence of "wet feet" and fungal
problems with the roots.

I don't know a thing about verticillium wilt, but I gather it is a soil
borne fungus which can result in de-foliation. Do there symptoms sound
likely, if so what do I do, if not, any ideas?

Regards,

Mike Wilson.
Hunter Valley.
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>--- In OliveOil@y..., "Mike Wilson" <mike.wilson@h...> wrote:
> I have a problem which I suspect may be related to Verticillium
Wilt (as I
> have run out of other options).
>
>
> Mike Wilson.
> Hunter Valley.

Mike, do the trees demonstrate any thinning of the trucks close to
the ground? I had a situation of possibly 100mm of thining (sort of
what you would imagine would happen if you grabbed the tree and gave
it a tug).

Jon McDowell
Wallan, Victoria
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>> --- In OliveOil@y..., "Mike Wilson" <mike.wilson@h...> wrote:
> > I have a problem which I suspect may be related to Verticillium
> Wilt (as I
> > have run out of other options).
> >
> >
> > Mike Wilson.
> > Hunter Valley.
>
> Mike, do the trees demonstrate any thinning of the trucks close to
> the ground? I had a situation of possibly 100mm of thining (sort of
> what you would imagine would happen if you grabbed the tree and gave
> it a tug).
>
> Jon McDowell
> Wallan, Victoria

No the trunks are normal.

My suspicions now turn to a soil-borne fungal disease, probably some form of
phytophthora. This is consistent with the symptoms, and as the land was only
recently cleared of native forest about 6 months before planting, there is a
strong probability of phytophthora from the old gum trees still being active
in the soil.
Many thanks to Steve Goodchild in Denman for steering me in this direction.

Mike Wilson.
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>I have been reading with interest Mike's problem with trees 'suddenly' dying
off. I am about 100Klms north of the Hunter Valley, and have had a similar
experience with trees that have been in the ground for more than a year, and
that appeared to be 'doing well'.

Peacock spot, root rot etc were considered, but rejected as the die-back
only happened with some trees -often in the middle of a row, seemingly at
random. Some I suspect were not 'well planted' as their root systems were
not well established, but others seemed to be thriving.

What is phytophthora and how is it treated?

Any other good suggestions? What are the implications of planting close to
native gum trees and on recently cleared paddocks?

Cheers

David Laws
Bucca Wauka, Near Gloucester NSW

-----Original Message-----
From:
sentto-60195-4268-998354061-david=globalpartners.com.au@returns.onelist.com
[mailto:sentto-60195-4268-998354061-david=globalpartners.com.au@returns.onel
ist.com]On Behalf Of Mike Wilson
Sent: Monday, 20 August 2001 6:42
To: OliveOil@yahoogroups.com
Subject: Re: [OliveOil] Re: Verticillium Wilt


> --- In OliveOil@y..., "Mike Wilson" <mike.wilson@h...> wrote:
> > I have a problem which I suspect may be related to Verticillium
> Wilt (as I
> > have run out of other options).
> >
> >
> > Mike Wilson.
> > Hunter Valley.
>
> Mike, do the trees demonstrate any thinning of the trucks close to
> the ground? I had a situation of possibly 100mm of thining (sort of
> what you would imagine would happen if you grabbed the tree and gave
> it a tug).
>
> Jon McDowell
> Wallan, Victoria

No the trunks are normal.

My suspicions now turn to a soil-borne fungal disease, probably some form of
phytophthora. This is consistent with the symptoms, and as the land was only
recently cleared of native forest about 6 months before planting, there is a
strong probability of phytophthora from the old gum trees still being active
in the soil.
Many thanks to Steve Goodchild in Denman for steering me in this direction.

Mike Wilson.


-----------------------------------------------------------------
Inviting others to join this group is simple: Just ask them to
send an empty message to: OliveOil-subscribe@yahoogroups.com
-----------------------------------------------------------------
For more information: http://groups.yahoo.com/group/OliveOil
Post message: OliveOil@yahoogroups.com
Subscribe: OliveOil-subscribe@yahoogroups.com
Unsubscribe: OliveOil-unsubscribe@yahoogroups.com
List owner: OliveOil-owner@yahoogroups.com
------------------------------------------------------------------

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>>What are the implications of planting close to
> native gum trees and on recently cleared paddocks?

How close? Closer than 15m will see the olive tree struggle depending on
what type of gum. A 30m gap would be preferable.

Regards
Peter Caird
www.victorianolivegroves.com
0418 392 157
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>>
> Peacock spot, root rot etc were considered, but rejected as the die-back
> only happened with some trees -often in the middle of a row, seemingly at
> random. Some I suspect were not 'well planted' as their root systems were
> not well established, but others seemed to be thriving.
>
> What is phytophthora and how is it treated?
>
> Any other good suggestions? What are the implications of planting close to
> native gum trees and on recently cleared paddocks?
>
> Cheers
>
> David Laws

David,

Sad to see you have a problem, but perhaps we are on the way to a solution!

Phytophthora (according to my sources of information) is a soil borne fungal
disease which destroys the fine hair roots of trees. Many of the eucalypts
seem to be immune (or at least not badly affected) to it, so as the clearing
of native vegetation usually means there is still some root material left
behind in the soil, there is a strong chance of the phytophthora being left
behind too, and this then attacks the newly planted trees. It also seems
that phytophthora is most active and devastating in winter and in cold wet
conditions.

This information is culled from various sources and relates mainly to other
crops rather than olives, so it is all subject to being totally wrong.
My local agronomist seemed to suggest ripping the whole lot out, returning
the land to grazing for ten years, then deep ripping and lots of serious
soil drainage work was the best practice, but I did point out that there are
some practical difficulties with this plan!

I intend to do a trial run using a systemic fungicide (Aliette) to see if
this helps, as the packet does say it is for phytophthora root rots, but as
this is not an approved chemical I will have to go through the NRA to get a
temporary permit issued first.
Ridomil Gold is approved, but for nursery use only, and I think the grape
farmers use Fongorid (sp?), but I'd be interested in any information that
anybody else has.

I suspect that soil drainage is still going to be the key, as if I can
manage to create an area of well drained soil (on a mound?) and enough roots
grow in this mound of decent soil, the smaller percentage of roots in in
the cold, wet stuff shouldn't be as critical.

If you want to have a chat about this my mobile is 0419 244785.

Regards,

Mike Wilson.
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>Have you a course of action planned yet?

Gerhard Grasser

"A man should farm as though he would live 1,000 years but live as though he
were to die tomorrow.

----- Original Message -----
From: "Mike Wilson" <mike.wilson@hunterlink.net.au>
To: <OliveOil@yahoogroups.com>
Sent: 20 August, 2001 6:41 PM
Subject: Re: [OliveOil] Re: Verticillium Wilt


>
>
> > --- In OliveOil@y..., "Mike Wilson" <mike.wilson@h...> wrote:
> > > I have a problem which I suspect may be related to Verticillium
> > Wilt (as I
> > > have run out of other options).
> > >
> > >
> > > Mike Wilson.
> > > Hunter Valley.
> >
> > Mike, do the trees demonstrate any thinning of the trucks close to
> > the ground? I had a situation of possibly 100mm of thining (sort of
> > what you would imagine would happen if you grabbed the tree and gave
> > it a tug).
> >
> > Jon McDowell
> > Wallan, Victoria
>
> No the trunks are normal.
>
> My suspicions now turn to a soil-borne fungal disease, probably some form
of
> phytophthora. This is consistent with the symptoms, and as the land was
only
> recently cleared of native forest about 6 months before planting, there is
a
> strong probability of phytophthora from the old gum trees still being
active
> in the soil.
> Many thanks to Steve Goodchild in Denman for steering me in this
direction.
>
> Mike Wilson.
>
>
> -----------------------------------------------------------------
> Inviting others to join this group is simple: Just ask them to
> send an empty message to: OliveOil-subscribe@yahoogroups.com
> -----------------------------------------------------------------
> For more information: http://groups.yahoo.com/group/OliveOil
> Post message: OliveOil@yahoogroups.com
> Subscribe: OliveOil-subscribe@yahoogroups.com
> Unsubscribe: OliveOil-unsubscribe@yahoogroups.com
> List owner: OliveOil-owner@yahoogroups.com
> ------------------------------------------------------------------
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>I'd like to propose two alternatives to the phytopthora issue, apart from
drainage which will lessen the problem to a more seasonal one and the 'hit
it with a chemical' approach.

1. The use of liquid kelp in avocado plantations and sensitive proteas has
been very successful. Drenching the soil with a heavy dose and then regular
foliar sprays seems to do the job. Whether the kelp stimulates more root
development (a very important feature of quality liquid kelp products) or in
fact attacks the disease is still out for the jury to decide.

2. Have heard recently that there is a soil biological claimed to attack the
phytopthora. Don't know of any other details at this stage but the advent of
soil biological inputs and knowledge is bringing us into a new era of
farming.

For those of you interested, the world leading exponent of Soil Biology will
be speaking at a soils conference at Moama, in NSW Australia for 3 1/2 days
commencing 30th August - 2nd Sep 2001. Please let me know if you want more
details.


Gerhard Grasser
Secretary, Gippsland Organic Livestock

AgriSolutions Pty Ltd
PO Box 81
Darnum VIC 3822
Australia.

Phone/fax 03 5627 8663
Mobile 0402 213 736

*** GreenTek non-chemical weeding systems
*** Soil fertility specialists - Albrecht principles
*** Independent soil, water & foliage testing
*** Kelp, seaweeds and fish for soil, plants and animals
*** Natural farming advisory service

"A man should farm as though he would live 1,000 years but live as though he
were to die tomorrow."
----- Original Message -----
From: "Mike Wilson" <mike.wilson@hunterlink.net.au>
To: <OliveOil@yahoogroups.com>
Sent: 21 August, 2001 6:43 PM
Subject: Re: [OliveOil] Re: Verticillium Wilt


> >
> > Peacock spot, root rot etc were considered, but rejected as the die-back
> > only happened with some trees -often in the middle of a row, seemingly
at
> > random. Some I suspect were not 'well planted' as their root systems
were
> > not well established, but others seemed to be thriving.
> >
> > What is phytophthora and how is it treated?
> >
> > Any other good suggestions? What are the implications of planting close
to
> > native gum trees and on recently cleared paddocks?
> >
> > Cheers
> >
> > David Laws
>
> David,
>
> Sad to see you have a problem, but perhaps we are on the way to a
solution!
>
> Phytophthora (according to my sources of information) is a soil borne
fungal
> disease which destroys the fine hair roots of trees. Many of the eucalypts
> seem to be immune (or at least not badly affected) to it, so as the
clearing
> of native vegetation usually means there is still some root material left
> behind in the soil, there is a strong chance of the phytophthora being
left
> behind too, and this then attacks the newly planted trees. It also seems
> that phytophthora is most active and devastating in winter and in cold wet
> conditions.
>
> This information is culled from various sources and relates mainly to
other
> crops rather than olives, so it is all subject to being totally wrong.
> My local agronomist seemed to suggest ripping the whole lot out, returning
> the land to grazing for ten years, then deep ripping and lots of serious
> soil drainage work was the best practice, but I did point out that there
are
> some practical difficulties with this plan!
>
> I intend to do a trial run using a systemic fungicide (Aliette) to see if
> this helps, as the packet does say it is for phytophthora root rots, but
as
> this is not an approved chemical I will have to go through the NRA to get
a
> temporary permit issued first.
> Ridomil Gold is approved, but for nursery use only, and I think the grape
> farmers use Fongorid (sp?), but I'd be interested in any information that
> anybody else has.
>
> I suspect that soil drainage is still going to be the key, as if I can
> manage to create an area of well drained soil (on a mound?) and enough
roots
> grow in this mound of decent soil, the smaller percentage of roots in in
> the cold, wet stuff shouldn't be as critical.
>
> If you want to have a chat about this my mobile is 0419 244785.
>
> Regards,
>
> Mike Wilson.
>
>
>
>
> -----------------------------------------------------------------
> Inviting others to join this group is simple: Just ask them to
> send an empty message to: OliveOil-subscribe@yahoogroups.com
> -----------------------------------------------------------------
> For more information: http://groups.yahoo.com/group/OliveOil
> Post message: OliveOil@yahoogroups.com
> Subscribe: OliveOil-subscribe@yahoogroups.com
> Unsubscribe: OliveOil-unsubscribe@yahoogroups.com
> List owner: OliveOil-owner@yahoogroups.com
> ------------------------------------------------------------------
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>> Have you a course of action planned yet?
>
> Gerhard Grasser
>

I don't know if you saw my other post, but I'm going to try a systemic
fungicide once I get approval and have some new leaf growth to squirt it at.
I've found foliar sprays are much more effective where I have some fairly
new leaves as a target, as the year old leaves are a bit too waxy and hard
to take spray up all that well.

Do you have any ideas?

Regards,

Mike.
</pre>
</td></tr></table>

<table border=0 cellpadding=2 cellspacing="0"><tr><td>
<pre>Your thinking is good in regard to spraying on older leaves. Younger leaves
are more receptive to foliar sprays, but in any case would recommend the use
of a spray oil to make the spray stick.

Don't know if you are going to get an ongoing result with fungicide.
Phytopthora is very persistent and the results I know about have been quite
disappointing.


Gerhard

"A man should farm as though he would live 1,000 years but live as though he
were to die tomorrow."

----- Original Message -----
From: "Mike Wilson" <mike.wilson@hunterlink.net.au>
To: <OliveOil@yahoogroups.com>
Sent: 22 August, 2001 4:52 PM
Subject: Re: [OliveOil] Re: Verticillium Wilt


>
>
>
> > Have you a course of action planned yet?
> >
> > Gerhard Grasser
> >
>
> I don't know if you saw my other post, but I'm going to try a systemic
> fungicide once I get approval and have some new leaf growth to squirt it
at.
> I've found foliar sprays are much more effective where I have some fairly
> new leaves as a target, as the year old leaves are a bit too waxy and hard
> to take spray up all that well.
>
> Do you have any ideas?
>
> Regards,
>
> Mike.
>
>
>
> -----------------------------------------------------------------
> Inviting others to join this group is simple: Just ask them to
> send an empty message to: OliveOil-subscribe@yahoogroups.com
> -----------------------------------------------------------------
> For more information: http://groups.yahoo.com/group/OliveOil
> Post message: OliveOil@yahoogroups.com
> Subscribe: OliveOil-subscribe@yahoogroups.com
> Unsubscribe: OliveOil-unsubscribe@yahoogroups.com
> List owner: OliveOil-owner@yahoogroups.com
> ------------------------------------------------------------------
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
</pre>
</td></tr></table>