Tuesday, November 30, 2010

McLaren Vale's Geology Map Project continues...

Today James met with McLaren Vale Geology Map co-author Jeff Olliver to do some ground truthing of the McLaren Vale Geology Map. Vineyard owners the Ledson family were kind enough to show us soil pits they have dug in their paddock.

The paddock is directly south west of Manning's Scrub in an area that used to be a market garden at the turn of the 20th century. Later in the sites history the paddock was mined for sand.

The geology under the sand is Pirramimma Sandstone, with seams of Ironstone.



Left - The formation of Ironstone occurs when sand, which has iron leached through it, is bound together and turns into rock (below). Ironstone is widespread source of iron (Fe), although it only contains less than 50 percent iron, far less than the main source of iron that is mined in central Australia hematite.

Thursday, November 25, 2010

Downy Mildew - UPDATE 25/11/2010

ADELAIDE HILLS – RED ALERT.

Last night, the 24th of November was a Downy Mildew Secondary Spread Event.

The Adelaide Hills Wine Region has had;

1) 10:10:24 Primary Event – 30th October
2) Confirmed oilspots from this 10:10:24 Event.
3) Two Downy Mildew Secondary Events (Warm, Wet Nights) 12th and 14th of November.
4) Confirmed secondary oilspot spread including some onto inflorescences.
5) A further Downy Mildew Secondary Event occurred which will spread oilspots onto vineyards that WERE NOT PROTECTED with good coverage of a Downy Mildew protectant in the last 5 days.

What does this mean?

The Adelaide Hills is likely to have a Downy Mildew outbreak – and because vineyards are pre-flowering - if left uncontrolled this will affect vineyard yields.

Get specific advice for your situation.

CropWatch - 101126


MCLAREN VALE –


South of McLaren Vale has no known Downy Mildew and Downy is unlikely to affect harvest or vineyard yields. We will advise if we find any oilspots.

North of McLaren Vale, it is wise to keep up protection before any further rain events as we have seen minor secondary spread north of McLaren Flat. We assume that the Clarendon region at risk of Downy spread as the weather has been similar to the southern Adelaide Hills where we know we have Downy Oilspots.

CURRENCY CREEK –

Get specific advice. Keep an eye out for Downy Mildew oilspots (below).

Tuesday, November 23, 2010

Pest and Disease - UPDATE 23/11/10

Flowering is underway in all varieties in McLaren Vale. Adelaide Hills vineyards are about 2-3 weeks away.

Conditions have been ideal for a successful flowering and berry set. Capfall has occurred rapidly in all varieties in all locations. Later blocks and varieties will complete flowering over the coming days. Shiraz Blocks should finish flowering next week. Chardonnay will begin setting berries next week.

The season is about 3 weeks later than last year and about a week later than the 2004, 2005 and 2006 vintages, which we not significantly affected by droughts, or heat waves.

Powdery Mildew


Powdery Mildew is a creeping disease. It ‘hides’ deep in the canopy. Under humid overcast conditions Powdery multiples more quickly. Powdery doesn’t need rain to spread, but it does do well in the humid conditions before and after rain showers.

Many hours during recent days and nights have had temperatures between 20 and 28oC - this means that the temperature for Powdery has been ideal favouring maximum production of spores.

We have seen some very significant Powdery Mildew in poorly covered vineyards (below).

Powdery Mildew in the upper surface of a vine leaf.

We believe Powdery Mildew pressure is very high this season – and growers should take care to keep up a good coverage over flowering.


The good news is good coverage = good disease control. Good effective sprays now before the canopy gets too big to spray are worthwhile.

Downy Mildew


Downy Mildew is a wet disease and needs rain to start its lifecycle. Some Downy Mildew has been seen in any Adelaide Hills vineyards. This confirms that regions CropWatch’s recommendations that a Downy Mildew infection occurred when 10:10:24 Primary Event conditions were recorded at the end of October.

Berries that are bigger than peasize (EL 31) are resistant though the bunch stalks and the leaves remain susceptible.

Growers in the Adelaide Hills must protect their vineyards as close as possible to any Downy Mildew secondary events (warm, wet nights).  


These warm, wet nights spread Downy Mildew onto unprotected leaves and bunches.

Vineyards in Currency Creek have a low level of Downy Mildew and should take a similar approach to growers in the Adelaide Hills.

McLaren Vale only have one confirmed vineyard with Downy Mildew at McLaren Flat. Caution is needed in the district, and if more rain events occur keeping up protection with registered Downy Mildew products is a low risk strategy.

Light Brown Apple Moth


Light Brown Apple Moth residue in a flowering vine inflorescence.
Check your flowers for signs of caterpillar damage. Apple moth damage is usually found in ‘hotspots’. If you find one damaged flower like this (above) check other bunches and in nearby leaves for more apple moth activity.

We have seen a big increase in the number of newly hatched Apple Moth in all subregions of McLaren Vale. We are also beginning to see Apple Moth in the Adelaide Hills.

Vine Moth caterpillar.
Vine Moth have also hatched in vineyards over the last 14 days. These hatchings are also found in hotspots or clusters (left).

Botrytis


Botryis Bunch Rot needs rain or moisture to spread. Any Botrytis present in your vineyard now is ‘dormant’ inside your berries or present in small amounts on any flower caps or dead plant material trapped inside bunches as they close. No rain before harvest = no botrytis.

Friday, November 12, 2010

Powdery Mildew - RED ALERT - UPDATE 12/11/2010

Weather conditions in the last 48 hours have caused Powdery Mildew to spread rapidly in poorly protected vineyards. These pictures were all taken today and show very fresh sporulation and leaf, stem and, most concerning infloresence infection - below.


Once established in a vineyard like this Powdery Mildew is almost impossible to remove. Powdery Mildew is a creeping disease. It ‘hides’ deep in the canopy. Under humid overcast conditions Powdery multiples more quickly.

Powdery doesn’t need rain to spread, but it does do well in the humid conditions before and after rain showers.

In the vineyard pictured the level of powdery mildew is already threatening to affect the quality of the fruit and leaf infections are very easy to see - below.



Powdery is a MAJOR concern in blocks which have a history of disease.

The good news is good coverage = good disease control. Good effective sprays now before the canopy gets too big to spray are worthwhile.

Wednesday, November 10, 2010

Some chance of a Downy Mildew Primary Event in McLaren Vale / Adelaide Hills.

DJ's uses Spraywise Decisions to predict weather events as they are forecast.

Spray Wise 10112010

The weather expected on Friday the 12th of November and Saturday the 13th of November has some chance of being a Downy Mildew Primary Event (10:10:24) and / or a Downy Mildew Secondary Event (Warm, wet night).

For the McLaren Vale / southern Adelaide Hills region, rain is predicted to begin at 10am on Friday the 12/11. This is expected to last until 9pm the same day.

Looking at the data as predicted, weather conditions will ONLY be favourable for Downy Mildew if vineyards stay wet between 10am Friday and the start of the rain on Saturday. If they dry out in between the 24 hours of leaf wetness needed for a Downy Mildew Primary Event(10:10:24) is unlikely.

A Downy Mildew Secondary Event (Warm. wet night) may occur if rain is still falling during the four hours before dawn on Sunday morning. This is concern of the Adelaide Hills region including Range Rd, which MIGHT have Downy Mildew oilspots from a probable Primary Event on the 27th/28th of October, and also McLaren Flat which has had a confirmed oilspot.

For most vineyards the threat of Downy Mildew is low, but it pays to get specific advice and keep up Downy Mildew protection if more rain events occur in the next month.

Tuesday, November 9, 2010

First Downy Mildew oilspot has been seen in McLaren Vale.

Matthew Wilson has found a single oilspot in McLaren Flat confirming the thoughts of McLaren Vale CropWatch and the DJ's staff that McLaren Flat was likely to have some Downy Mildew from the weather of the 29th and 30th of October.


Above - A single oilspot that has been put through the Downy Mildew bag test to confirm it is a 'real' oilspot.

What does this mean?

Downy Mildew is a rare disease and one oilspot does not mean an outbreak will occur. It is not the time for panic spraying.

What we do think is this;

Firstly, we can have confidence in the weather data from the McLaren Vale CropWatch weather station. It showed a very near miss for a Downy Mildew (10:10:24 Event), which meant that there was some chance of oilspots occuring nearby where the weather was slightly wetter for a longer time.

Secondly, growers in the Northern half of McLaren Vale should keep up Downy Mildew protection in few that rain is forecast for Saturday.

As always if you have any questions about your specific situtation ring us on 08 8323 8339.

Red alert for the Riverland - Downy Mildew Status as of 5pm 9/11/2010

RED ALERT


Primary Event and multiple secondary events have caused a Downy Mildew outbreak to begin. Rain is expected to be suitable for further Downy Mildew secondary events, warm wet nights, on Saturday and Sunday.

Our sources in the Riverland have taken these photos showing what to look out for;

Downy mildew on flowers.
Downy mildew on a leaf.











Left - Downy Mildew on inflorescences after an overnight bag test.  
Right & Below - Downy Mildew spread on leaves.

Downy mildew on the front side of a chardonnay leaf
Get professional advice - Now!

Downy Mildew is a rare disease and as such needs specialist advice specific for your situation.

With vines rapidly growing - there will be a much shorter period of effective cover. Shorten the intervals and don't assume that just because sprays went on that you have avoided infection.

Be skeptical of rain fastness with over 25mm of rain. If over this amount of rain occurs it is likely to wash off most of your protection.

If in any doubt - and primary infection (10:10:24) and/or a secondary infection (warm, wet, night) is confirmed - spray with metalaxyl rather than relying on the action of protectants. This is especially relevant with patches that will suffer fungal attack from subsequent secondary infections at / close to flowering.

You cannot kill oilspots once they are visible. You can only control their spread.

_________

 

Unless effective action is taken now, yield loss is likely in the Riverland this season as inflorescences are vulnerable to infection at this stage of the season, Capfall, EL 19-25.

_________

Stock shortages of Downy Mildew products as the Riverland faces Downy outbreak.

Grapegrowers are finding it difficult to get hold of Downy Mildew products this season. Derek Cameron reports there are two reasons for this; 

He says,
"One, the wet broadacre season, particularly in the eastern states, has seen Downy protectants soaked up by the Lentil, Bean, Chickpea market, an example is they created a permit for Captan for Lentils after all other products were sold out, and this saw all of SA’s forecast for Captan go east in a week (even though I had ordered mine in February). More supplies of this are coming, but probably too late.

Two, the amount above does not explain the shortage of Sulphur. It is likely that the GFC has seen suppliers focus strongly on reducing stored stock. The financial position of NuFarm (which is also CropCare) the two major suppliers of Sulphur (CropCare make Top Wettable, Kumulus, Notion etc.) has also not helped. Nufarm has been tightening its belt in response to its profit bottom line."
This shortage has lead to a potentially dangerous situation as a Downy Mildew outbreak is occurring in the Riverland and Mildura regions of South Eastern Australia. It it likely to become necessary to lobby the industry and specifically wine companies purchasing the fruit this season to allow the use of Phos. Acid as an eradicant Downy Mildew measure.

Derek also thinks that other products can be used when under Downy Mildew pressure;
"I would consider Flint/Cabrio similar to Copper/Mancozeb/Captan/Chlorothalonil as a protectant against Downy. The extra advantage of Flint/Cabrio over the others is they have the ability to redistribute with moisture which helps with expanding bunches. They are strongly bound to green tissue which also helps bunches."
Derek can be contacted at DJ's Growers for more information.

Tuesday, November 2, 2010

Tractor Action Grinds McLaren Vale to a standstill.




FROM THE ABC.

Communities directly affected by the South Australian Government's development plans have rallied against housing proposals.

But SA Planning Minister Paul Holloway says they will have to wear population increases to help cater for Adelaide's expansion.

Some were angered by a planned housing estate at Seaford Heights.

"Change the face of McLaren Vale [and it] won't have the appeal for tourists that'll want to come here and spend their dollar here, said one.

The protesters brought McLaren Vale to a standstill as they made clear their views.

Their convoy travelled to a Seaford Heights winery, just metres from where more than 1,000 homes are to be built.

Mount Barker residents are also keeping up the pressure against Government plans to rezone Adelaide Hills farmland for housing.

Opponent Ian Grosser vowed the fight would continue.

"We'll maintain the rage yes. Unfortunately the Planning Minister, despite the opposition, shows no sign of backing down," he said.

Mr Holloway defended expansion plans.

"What we're trying to do is to say 'Well look, if we're going to have the growth, let's try and contain it to a few centres, let's try and make that efficient so that we can provide the infrastructure that's necessary'," he said.

The Minister said the land at Seaford was earmarked for development two decades ago.

Monday, November 1, 2010

Powdery Mildew - ID Photos




Look for powdery mildew in before flowering (Capfall EL-19) - including flagshoots and heavy infestations as pictured above and below.


DURING FLOWERING (CAPFALL) BE ALERT. MAKE SURE YOUR GET GOOD COVERAGE AND KEEP YOUR SPRAY INTERVALS CLOSE IF YOU HAVE PROBLEM VINEYARDS.


Downy Mildew Report - McLaren Vale - UPDATE 1/11/2010

CropWatch 1011_vol8_12

McLaren Vale - Generally very good news. The region has missed out on a widespread Downy Mildew Event.

Looking at the weather over the week I predict the following will happen.

A very small amount of Downy Mildew Oilspots will become visible after an incubation period of 7-10 days IN VINEYARDS THAT WEREN'T PROTECTED with a Downy Mildew fungicide in days before the rain.

It will take vineyards monitors a few weeks to find these, as there won't be many.

These oilspots will be only in locations that stayed wet for the 24 hour period of Friday into Saturday. This will be in creeklines or similar - and mainly in the Northern part of the district, particulary McLaren Flat where the weather got closest to a Downy Mildew 10:10:24 Primary Event.

What does this mean for my vineyard? To be safe and take a low risk approach it is recommended to keep up Downy Mildew protection - especially if more rain is forecast.

In general it is good news, but remember that while everyone gets excited about Downy Mildew - Powdery Mildew is the main concern in the district at the moment.