Tuesday, March 23, 2010

Adelaide Hill Harvest - UPDATE 23/3/2010

The early ripening Shiraz blocks are being harvested this week in the Adelaide Hills. The lion’s share of Shiraz should come off this week or next.

The shower activity and cooler forecast for next week may speed the rate of shiraz intake. Blocks are clean and healthy. Leaf senescence is increasing in shiraz blocks (above). Merlot and Cabernet Sauvignon canopies are holding onto their leaf well. These varieties will need these leaves to get them full ripe this season. This may take a further 2-3 weeks in the coolest sites.

Wednesday, March 17, 2010

Post Harvest Irrigation and Nutrition - What, why and when?

Summary from GWRDC research.
The importance of the post-harvest period is largely determined by climate, variety, yield, and management prior to harvest. Vines will tolerate a season or two with limited post-harvest irrigation, but productivity will eventually be reduced if this continues over many seasons. Although beyond the scope of this module, the importance of long term planning needs to be emphasised if water shortages are expected to continue. This includes understanding that cropping levels, together with effective salinity management, are two key factors in determining the sustainability of vines with reduced water supply.

Uptake of other minerals may be equally important during the post-harvest period, but relative to nitrogen, a lot less is known as to their role as reserves. The cycling of nutrients, and thus ability to store and remobilize again in spring, depends on their mobility within the plant. This is high for all the macronutrients, except calcium, which has low mobility. With the exception on manganese, which is also low, all the other micro nutrients have intermediate mobility.

As a rough guide to the relative importance of different nutrient reserves (where such information exists), studies with whole mature vines have shown that about 50% of nitrogen and phosphorus in the new seasons canopy comes from stored reserves. Around 15% of potassium comes from reserves, but less than 5% of magnesium and calcium.

A considerable proportion of these nutrient reserves can be up-taken and stored in the post-harvest period the previous year, with about one third of the annual nitrogen and phosphorus requirements stored after harvest, and about 20% for magnesium and calcium, and 15% for potassium. As indicated by some macro nutrient level increases during the post-harvest period, the application of fertiliser during this period allows nutrient status to improve and reduces potential deficiencies in the following growing season. It has been shown, for example, that post harvest nitrogen application is reflected in the petiole concentration at flowering. Post-harvest nutrient applications may therefore make an important contribution to the growth and general health of vines in the following season.

Key points regarding nutrient reserves are:

• Like carbohydrates, grapevines require a supply of nutrients from stored reserves to support growth in early spring. Nitrogen in the roots and wood follows a similar pattern to carbohydrates (although much lower in concentration), and post-harvest applications will influence the nitrogen status of the vine in the following season.

• The role of other nutrient reserves is less well understood, but post-harvest uptake of phosphorus does appear to be important. To a lesser extent, magnesium, calcium and potassium uptake after harvest will also contribute to growth in the following spring. Little is known about the role of other nutrients carried over winter in grapevine tissues.

Further reading.


Wednesday, March 10, 2010

Powdery Mildew on bunch stalks - ID Photos

Above: Late season Powdery Mildew can flare up and infect bunch the racchi and any 'green' unset berries. This type of infection is not considered to affect wine quality as the fruit (the berry) is immune from Powdery and does not have any Powdery on its surface.

Careful harvesting may be necessary. Machine harvesting will remove the fruit and leave behind the infected racchi. Care needs to be taken, it is best not to pick very hard when you see infected racchi, so as to not contaminate the grape load by shaking them off as well as the fruit.

Tuesday, March 9, 2010

Botrytis has been triggered by the rain this weekend - UPDATE 9/3/2010

Above: Old leaves can get botrytis infections. Overseas, particularly in New Zealand, leaf plucking and other methods like forcing air through the canopy are used to clean out dead vine material to remove host sites for botrytis.

Thursday, March 4, 2010

Generational Farming Workbook Launch

Above - The Generational Farming workbooks were given out at McLarens on the Lake, yesterday the 3rd of March.

What is Generational Farming?

Generational Farming is the McLaren Vale wine region’s sustainability accreditation scheme. The Workbook has been developed by a group of local viticulturists for the region, and builds on many years of work and knowledge.

The system is designed to fit in with the national ENTWINE system.

Workbook version. 1 is being distributed to grape growers that have indicated their willingness to participate in Generational Farming, in this first year (2009/10). Sixty businesses are starting the programme, which McLaren Vale Grape Wine and Tourism Association chair Dudley Brown says 'represents something like 30% of McLaren Vale's vineyard area.'

The workbook is a work in progress, and the first batch of growers will be giving feedback to make changes to the system to make it the best possible.

There are five sections in the workbook, all with points allocated, totaling 1000 points altogether. The system is not a competition, the main reason for a points system is to allow grower to assess themselves and work out where they can improve their practices. Particularly for this first year, do not be too concerned with the points, we are still determining what level will be considered best practice and therefore a ‘pass’ mark.

After an AUSQUOL audit growers will be either 'Accredited' of 'Not-accredited.'

The system doesn't promote any specific type of farming - like BioDynamics or conventional best practice - it is designed to be a questionaire of your practices with prompts to provide documentation for proof for your audit.

Generational Farming ‘Ambassadors’

A group of local viticulturalist and grape growers have been recruited as ‘Ambassadors’ to assist growers with the workbook, these are key people in the region that you can contact for assistance. Each Ambassador will have a group of 4 or 5 growers, those growers can decide to meet to work through any issues or just contact the Ambassadors when they need help or have a question.

The Ambassadors are:

• Jodie Armstrong
• Derek Cameron
• Guilio Dimasi
• Jock Harvey
• Tony Hoare
• James Hook
• Adam Jacobs
• Michael Lane
• Daniel Lavrencic
• Jodie Pain
• Michael Petrucci
• Ben Pridham
• Matt Hatwell

Process from here;

Ambassadors are being allocated to growers in early April and their contact details will be sent through, if there is an Ambassador that you already work with, please let Jodie at McLaren Vale Grape Wine and Tourism know if you would like to be in their grower group.

You can commence filling out your workbook based on 2009/10 growing season, and your Ambassador will contact you in early April to meet through April and May as needed, with Workbooks to be completed by the end of May.

A feedback/ question/ comment form has also been provided for you to keep track of any issues or questions as you go. These will also be used to provide feedback on the workbook, and system in general for us to make improvements for the next growing season.

In the interim if you have any questions, please contact Jodie Pain, Viticulture Coordinator on 8323 8999 or email jodie@mclarenvale.info

Wednesday, March 3, 2010

New machine harvesting technology in SA.

We have seen some interesting developments with grape harvester technology this year. Check out the Pellenc sorting harvester.

The new Pellenc harvester was put through its paces in a block of Cabernet in McLaren Vale yesterday afternoon. The result was impressive - it was picking twin cordon cleanly @ ~3.6km/h!

Also on display was its berry sorting feature, it de-stems and removes the vast majority of the MOG through a very elaborate set of shakers, fingers and rollers on top of the machine. Seemed to do an excellent job.

It also carries the fruit on board rather than using an elevator into a chaser bin. Instead the fruit is carried in two hoppers that tip separately at the back of the unit - total capacity is ~2.5t according to the operators. As a result there was only one tractor/gondola used tipping into a bulk truck.

Overall we were pleased with the result and estimate it covered the 25 acres in around 15 hours.I wonder if its complexity will count against with regard to breakdowns, but time will tell I guess!

Link to Pellenc harvester newsletter - http://www.pellenc.com.au/Default.aspx?tabid=721

Tuesday, March 2, 2010

Should we spray after harvest? Q&A

Should we spray sulphur on our vines after harvest?


There is much debate about whether vineyards should be sprayed after harvest Latest research would indicate that these sprays are often not needed.

Powdery mildew - Grape growers become concerned about high levels of Powdery mildew on their leaves (above).

1/ You might reduce the spread of powdery mildew in the canopy.

Powdery mildew late season on leaves
However, where disease has already developed, further increases in levels of powdery after–harvest generally make little difference to leaf and vine health.

2/ You might aim to reduce the amount of disease for next season.

Unfortunately spraying after picking has little effect on the chances of Powdery mildew next year.

Most buds that survive to next season are susceptible to powdery only in early growing season, so spraying now will not affect levels of winter-carryover in the buds. Also, the fruiting bodies of powdery, called cleistothecia, are somewhat like apples on a tree, they ripen in late summer and autumn. Since cleistothecia have already matured in most vineyards by now, post-harvest sprays are too late and do nothing to reduce their numbers.

Spraying for Rust Mite after harvest is also not recommended.

The Rust Mite bronzing to leaves you see are not doing any damage to your vine leaves and they function normally.

If you have bronzing on your leaves (above), record this as it is the threshold for rust mite spray next spring. Spraying in spring 2010 is recommended if uniform, moderate to high bronzing is obvious in your vineyard now (March 2010).

A spring spray aims to re-set the rust mite population down to a level where predatory mites can then maintain effective control. However, this approach does have some toxicity to predators therefore, using it when it is not needed can damage predators unnecessarily!