Thursday, November 27, 2008

Berry Shatter



Berry shatter has been seen in some vineyards. Some shatter can be the vines natural way to regulate its crop, however water stress during flowering can also wither fruit as shown top.

Wednesday, November 26, 2008

Lime Induced Chlorosis - Burgundy, France

In Winter 2008 Richard McGeachy traveled to Europe to investigate their viticulture and bring techniques back to McLaren Vale. Some of the issues faced in Burgundy are experienced here also. Iron (Fe) deficiency is a plant disorder known as "lime-induced chlorosis".

Limestone from the subsoil mixed into the topsoil by tillage.
This photo above was taken in the hills just to the west of the town of Gevrey Chambertin – showing the amount of limestone present in the freshly tilled paddock.
Severe lime induced chlorosis.Symptoms include leaves turning yellow or brown in the margins between the veins which may remain green, while young leaves may appear to be bleached.
This second photo shows severe lime induced chlorosis in a Pinot Noir vineyard near the town of Gevrey Chambertin.

A low level of lime induced chlorosis (yellow leaves).

This final photo above shows that some vineyards were more severely affected than others depending on the depth of top soil – and likely whether the grower was applying iron or not!

Growers in South Australia have had good success using EDDHA chelated iron to correct their iron deficiency induced chlorosis. Ironically most of these chelated iron products are imported from Europe.

Thursday, November 20, 2008

Heat Stress / Sulphur Burn - Identification Pictures

Sulphur Burn on young leaves.

Apple Moth - Predator and Prey - Identification Pictures

Light brown apple moth levels (LBAM) are high this season compared to the last few years.

Where apple moth are present they have moved into bunches. Look for ‘strings’ of brown flower caps stuck in bunches. You can also find at this time of the year LBAM pupae (grubs turning into moths in a cocoon) and egg masses.

Pictured is an egg mass, top and damage to the bunches, bottom.



Powdery Mildew - UPDATE 20/11/2008

Levels of Powdery in McLaren Vale and now in the Adelaide Hills have been seen to increase.


We have been seeing leaf spots across many vineyards. Pictured above is an inactive spot. Most of this is still at a very low level but some discoveries have caused growers to increase the frequency of their protective sprays to limit any spread. More significant signs of spread are shown below.


Check for Powdery before Christmas. Look for mildew on at least 50 bunches per block. Select the bunches from inside the canopy and look closely for grey-white mildew growth on the berries. If there is any sign of powdery, apply sprays of a suitable registered fungicide at 10-day intervals in attempt to stop the disease increasing.

The good news is if you get to Christmas clean : your bunches will be clean at harvest. Only bunch stems and leaves can get infected after that point.

Monday, November 17, 2008

Latest Powdery Mildew Finds - UPDATE 17/11/2008

Powdery mildew flagshoot.
Powdery mildew on a developing bunch.

Weather conditions are good for the spread of Powdery Mildew. Powdery does best in overcast and warm weather. Shady canopies in Shiraz and Chardonnay further assist the spread of the disease.

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

Soil simplified - Q&A


Hi,

Can you give some background information on soil chapter? What is soil made out of? Why do we talk about soil health?

Many thanks,

Kane


Thanks Kane.

Sustainability in reference to soil…


Sustainability is protecting and improving what’s there - so leaving the soil after 10 years of farming in better condition than what it was when you began.   Obviously if the opposite takes place then you’re only able to farm for a short period of time before you exhaust that soil’s ability to farm.

Measuring soil health is complicated. The McLaren Vale Sustainable Winegrowing Australia programme asks questions about soil organic matter, pH, salinity and erosion. All of these are component factors defining and monitoring a healthy soil.


Soil is a mixture of organic matter, air, water and minerals.


Your soil is made up of 4 materials.

1) Minerals - Clay or sand particles weathered down by various processes.
2) Air - Nitrogen, Oxygen, CO2 and other gases.
3) Water.
4) Organic matter - living things and their waste products.

Bacteria - microbes that live in the soil. Bacteria don't help soil structure as they stick onto the sides of minerals in the soil.

Fungi - also microbes that live in the soil. Fungi are very beneficial to soil as they bind the minerals in your soil together. Some types of fungi also join with plant roots and help extend your vines root system.

Biota - all of the living insects in your soil, earthworms, dung beetles, slaters to name a few.

In drought years you have little control over the water your soil holds. Even with irrigation the vine mid row is now dry and your vine roots in this part of the soil are not active. What you do have an influence on is the amount of organic matter in your soil. The activities of these microbes help by building humus.
Humus is organic matter which has reached a point of stability, where it will not break down, and if conditions do not change, remain as it is for many years.
Many of the key processes in BioDynamic farming / Sustainable farming are designed to boost the amount of organic matter (chiefly humus) in your soil.
Organic matter can be measured by the amount of organic carbon is in your soil. Level of 2% are common in McLaren Vale. Ideally growers should aim to double the amount of carbon in their soil as a start. This soil will benefit you by holding more water and will need less fertilisers because what is already present in the soil will be more available.

Friday, November 14, 2008

Wednesday, November 12, 2008

Bayer CropScience in Germany

Dear Growers,

As some of you know I was lucky enough to travel to Europe recently. During my travels I was fortunate to visit some manufacturers, suppliers and of course wine regions!

In the coming weeks I will be writing summaries about some of these places along with photographs of things I saw along the way. Let me start by thanking DJ’s for this opportunity, it was truly unforgettable!

Richard


Bayer Cropscience - Leverkusen Germany

Bayer employ some 109,000 people worldwide in the three major areas – Health care, Material Science and Crop Science. I visited a site just out Koln in Germany called Leverkusen. This site is unique because it holds a sample of all the active ingredients in Bayer products. A robotic catalogue manages the 4+ million samples in series of rows and stacks. Interestingly only the computer knows were each sample is via a bar code system and no human hands actually touch containers. It is all automated right up to the point where the chemist receives the required amount of active. The actives are selected, weighed, sampled and returned automatically across a series of rooms connected by conveyer.

They perform trials with selections of ‘actives’ on the major fungal diseases to discover if they have another mode of action. With such a large group of actives to choose from it is a long an involved process!



This photo shows some vines in one of the trials – more than likely involving, botrytis, powdery or downy. Due to the sheer number of actives to perform trials with they typically start with very low concentrations on the chosen pathogen (eg downy). If a reaction is evident at low concentration then further trial work is carried out using that active, with the knowledge that increasing the concentration will likely improve the response.

This site and another in Lyon in France handle the bulk of the CropScience trial work. Unfortunately the Lyon site was closed for summer holidays.

Tuesday, November 11, 2008

Assessing Quality for 2009 Vintage - UPDATE 11/11/2008


Vineyards on red clay loam, and those on sand look to have adequate vigour levels and are generally balanced. Some vineyards on heavy black, cracking clay, the ‘biscay’ soil, have short shoot development and are at risk of having unbalanced canopies at harvest. Assess your vineyard.

Simple fertilisers may not be the solution - if you pump up a big canopy you may not have enough irrigation to sustain over summer. Big canopy, and or a big crop has a big requirement for water.

Soil moisture levels in the mid row, far away from any irrigation you apply, are now likely to be dry. There are some parallels to Spring 2006 which lead to a light vintage 2007. Remember the lessons you learned from that year.

Thursday, November 6, 2008

Full Flowering - UPDATE 6/11/2008


The season is running early with some vineyards finishing flowering. Chardonnay in Willunga is at Berry Set (EL27) and some Cabernet Sauvignon is close to 80% Capfall (EL25).

Remember any withholding periods - 80% Capfall (EL25) is the AWRI cut off for many commonly used products.

No Downy Expected in McLaren Vale - UPDATE 6/11/2008

As of 12pm, Thursday the 6th of November the forecast weather is not suitable for a Downy Event for McLaren Vale. While an alert has been reported on radio via the Bureau of Meteorology, we believe the amount and the duration of rain is not enough to cause a 10:10:24 Downy Mildew Primary event. The Bureau reports rain beginning 3am and clearing Friday morning. There is an 80% chance of 5-10mm. Showers are expected Saturday and a possible shower Sunday.

If we are correct no action is required for Downy Mildew in grapevines.

Tuesday, November 4, 2008

10:10:24 - Downy Mildew Explained.

For Downy Mildew to infect vines it needs to be ‘triggered’ in the soil by rain and soil wetness over a 24 hour period.

Downy needs rain keeping the soil wet for 16 hours, so that its spores can germinate ready to cause infection in the leaves.

Above: Downy from Spring 2006. This season the weather has not been suitable to start the disease.


Any breaks in wetness over 2-4 hours stop Downy’s lifecycle. The spores need to be splashed to the leaves after the 16th hour and the leaves then need to remain wet for at least 2-3 hours, for infection to occur. In McLaren Vale windy conditions often prevent this from happening. In the Adelaide Hills, where valley and local conditions limit wind, Downy Mildew is more likely. 

Downy can move quicker than 24 hours if the temperature are above 10oC. Also, Downy can complete its infection below 10oC (down to 7-8oC) but takes longer than 24 hours.

Botrytis Risk - Up for Debate?

There is always a decision on whether to spray for Botrytis during flowering. Is it worth it?

For Organic and BioDynamic growers the best from defense is using and open canopy to assist with air flow around the bunches late in the season.

For conventional vineyards consider your Botrytis risk:

Variety


High - Sav. Blanc, Riesling, Grenache, Semillon, Chardonnay, Chenin Blanc, Viognier

Medium - Pinot Gris, Pinot Noir, Chardonnay, big bunched Shiraz, Sangiovese, Mataro/Mouvedre, Petit Verdot, Verdehlo

Low - Small bunched Shiraz, Merlot,

Very Low - Cabernet Sauvignon


The expected rain is likely to be conducive to Bunch Rots and as the young fruit-clusters start flowering (EL 19-20), will need protection. If your vineyard has a history of botrytis spray at full flowering - 80% capfall (EL 25).

If you have been using the same botrytis chemicals for a few seasons in a row consider AVCARE resistance management guidelines.

Click for AWRI Guidelines.There are several different chemical groups recommended for use to control Botrytis bunch rot: Switch (Group I+L), Scala (Group I), Teldor (Group J), carbendazims (Group A), Captan and Chlorothalonil - Bravo & Barrack (all Group Y).

LBAM have increased - UPDATE 4/11/2008


LBAM larvae have increased in vineyards this week. Good monitoring now will establish the levels in your vineyard at flowering. The flowering period (EL 19-25) is the critical timing for Apple Moth damage.
Some vineyards are opting to control Apple Moth with insecticide sprays. Note that some wineries like to be informed of this beforehand.