Monday, July 30, 2012

Dormex - Q&A

Michael asks; 

When should Dormex be applied to my Mourvèdre vines (near Willunga, SA)?

Before using Dormex® make sure you are aware of the health and safety implications of spraying it. Acute and chronic exposure to Dormex, hydrogen cyanamide (H2CN2), have been reported but mainly as a result of accidental exposure following by drinking alcohol.

EL 1. Winter bud.
Dormex is used as a dormancy breaking agent for grapevines. We use it to helping give uniformity to grape vine bud burst. 

When Dormex is applied 8-10 weeks before natural bud burst, fruit maturity will be advanced by 14-18 days. Application within 4-6 weeks of natural bud-burst had little or no effect on time of fruit maturity. 

For your example on Mouvedre in the Sellicks Foothills we expect natural bud burst to be the 2nd week of September. Therefore we recommend it is applied 4-6 weeks before this natural bud burst date to keep a natural harvest date. An application of Dormex should take place from the first week in August to the middle of the month.

If you are considering applying please contact DJ's for more information about product safety and rate of application.

Thursday, July 12, 2012

Pricing Volatility - McLaren Vale

McLaren Vale Historical Weighted Average. Click on the image for larger size.

The McLaren Vale wine industry is at a crossroad. The region has the potential to either slip back into over supply and therefore low grape prices, or else move into a period of stability. Which outcome occurs will depend on the size of our next vintage and that size of the national crush.

In the period Vintage 1993 to 2000 grape pricing, for both red and white varieties, followed a supply and demand curve. Prices increased as demand increased then prices decreased as supply was met and an oversupply began to develop.

This situation peaked in 2004 when McLaren Vale harvested its largest vintage of over 70,000 tonnes of grapes. For contrast the McLaren Vale 2012 total crush in McLaren Vale was 31,755 tonnes.

The total SA farmgate value in 2012 was $293m which is 43% below the average state farmgate value for the 5 vintages from 2001-2004 ($513m).

Regional farmgate pricing. It’s a long climb back.
As a state in 2006, SA crushed 900,000 tonnes from 74,600ha of vines. In 2012 we have 76,600 ha; that’s right more vines now.  So it would appear the risk of a high crop is increasing. Counter to that is that vine yields do appear to be lower and 90% of the vines are now more than 10 years old.

Since 2004, in the McLaren Vale region, yields have been lower but this has been due to environmental factors and changes to viticulture (capped tonnages). Dudley Brown notes - "In McLaren Vale, regional yields are down by 30-50% from just eight years ago. This is equivalent to 2000 – 3000 hectares of 'removals'". 

"Growers in McLaren Vale were famously told by Warren Randall," Dudley says (Warren is now the owner of Seppeltsfield and large vineyard holdings). "'You have to change. Grow A or B grades, get out, or go bust'" in a public meeting as early as 2005 – well before the Wine Restructuring Agenda was undertaken. It had real impact."

There has not been a large change in vineyard area with vineyards being top-worked in preference to removal but yields have been lower due to changes in viticultural practices. 

The Chardonnay Problem 

Since that peak white grape prices have continued to decline lead by Chardonnay the major white variety. Other traditional white varieties like Semillon and Riesling have also declined and are now not viable to produce. Prices for local Sauvignon Blanc have similarly declined and are close to the cost of production.

The prices for Chardonnay are also not viable to produce which is creating an imbalance in the local industry. There is pressure to convert Chardonnay vineyards into an alternative, generally into Shiraz or Tempranillo, and this is increasing  McLaren Vale red supply which in turn has affected their prices.

In brief, because the traditional white grape varieties cannot be grown profitably, growers swapped to red grapes.

A medium to long term alternative to Chardonnay needs to be found or developed for grape prices to be stable. This season McLaren Vale Vine Improvement has been seeing demand for Shiraz, Mouvedre and Tempranillo grafting materiel much of which is destined to be used to top-work Chardonnay, Semillon and Reisling. This will continue to lead to an increased percentage of the region being red grapes.

Young Shiraz being harvested in 2004; McLaren Vale's largest vintage to date.

Reds dominate; Reds fluctuate


McLaren Vale is approximately 75% red grapes – Shiraz, Cab Sav, Merlot, Grenache account for most of this with emerging varieties like Tempranillo increasing in plantings. The percentage of red grapes is likely to further increase with McLaren Vale becoming further dominated by red grape production.

With this concentration in red grape production it has become a case of ' putting all the eggs in one basket'.
Red grape prices have been volatile for the last five seasons with price spikes based on false shortages caused by weather in other regions. Low harvests as a consequence of drought and water restrictions (2007/08) and rain with corresponding flooding and disease (2011) have created localized demand in McLaren Vale. In response prices for Shiraz (and to a lesser extent Cabernet Sauvignon) have increased back to near their late 1990's peak.

This trend is expected to continue through 2013 after the 2012 Vintage was affected by rain on the eastern seaboard (especially the Hunter Valley region which has a history of grape trade with McLaren Vale). However this is likely to be a temporary spike for McLaren Vale. Around Australia, while there are signs of adjustment in vineyard area and wine stocks, these are not sufficient evidence to suggest the “oversupply problem” has passed.

Wednesday, July 11, 2012

Mycorrhizae - Soil science behind organics - Q&A

Mycorrhizae (My-Co-Rise-Ah) are a type of fungi which penetrates the cells of the roots of a plant and act in harmony with plant roots. In layman's terms they plug into your vines root system and greatly increase its size. With the help of the Mycorrhizae the vines root systems are much more effective.
Small fine roots in undisturbed soil.
Mycorrhizae are even smaller than these roots!
Unfortunately the fungi are sensitive to cultivation (it breaks them up) heavy fertilizer rates and herbicide (some promote bacteria at the expense of fungi, others destroy the fungi themselves).

The simple rules for maximising mycorrhizae are to limit;
  • Cultivation (preferably none)
  • Herbicide applications
  • Fungicide applications
Not easy to do as limiting herbicide and cultivation means weed control (to prevent excessive moisture usage) is hard too manage.

High levels of Mycorrhizae are one of the key benefits of Organic/BioDynamic farming systems. High levels of Mycorrhizae mean more efficient root systems. More efficient root systems means more robust plants better able to survive stress.

Tuesday, July 3, 2012

June Rainfall Summary

June rainfall was higher than the mean rainfall (78mm) contrary to earlier predictions of a dry winter. This is welcome for flushing the soil of salts that have built up over the last irrigation season - although note that moisture monitoring sensors are recording water has only penetrated down to 100cm on clay soils and they need additional rainfall to flush below the rootzone.

June Rainfall

Highest Daily Rainfall


Monthly Total


Annual total Jun 31st 2012  377.5 mm

Rainfall comparison

Rainfall Comparison Calendar Year