Wednesday, August 26, 2009

Info night - Sustainable Farming

We recommend you go!

Growers Information Night.

An Information Night is being held for all Grapegrower Members on Tuesday, 1st September 2009 at the Bocce Club, McLaren Vale. A pasta dinner is available for those who are interested in staying after the information session has concluded please RSVP to alex@mclarenvale.info if you are joining us for dinner.

Hail Damage in Willunga - UPDATE 26/8/2009

Some Hail damage has been seen around Willunga running in a rough line between Aldinga and the Willunga township. This was caused by a strong hail storm Monday night. Fortunately the damage we have seen is generally not economic - no crop has been lost. The vine shoots are however quite scarred and have dents in their shoots(above & below).

Experience from earlier seasons shows with warm weather this damage will 'grow out' and be difficult to notice in a few weeks. If you have hail damaged vines and are concerned about their early season growth please let us know. It may be advisable to try using some spring growth techniques like Kelp based products to aid recovery.

Don't confuse hail damage, with the fungal disease Phomopsis

Tuesday, August 25, 2009

Wet weather - Minor vine damage - UPDATE 25/8/2009

The region has been hit by very high winds and heavy rain showers. Fortunately while hail did fall Monday night no hail damage has been seen today. Indicator blocks like the one below are well past bud burst (EL 4) and are approaching 2-4 Leaves Developed (EL 7-8). These seem clear of damage. Good news.

Early vine development in McLaren Vale.
If your vines have burst (are past EL 4) check for any weather damage. Fortunately vines quickly recover from any wind rub and tearing like that shown below.

Wind damage to Sangiovese.

Wednesday, August 19, 2009

Early Season Budburst

Sangiovese in the Onkaparinga Hills district of McLaren Vale.
Budburst is early in McLaren Vale. Pictured above is Sangiovese which is a very early starter. Chardonnay is moving through budburst with stressed or unpruned vineyards at 1-2 leaf developed. Shiraz is expected to be at budburst at the end of August - approximately a week earlier than last season.

Our records since the year 2000 have seen budburst move from the middle of September to the last week of August. Some of this trend is explained by the average vine age of the district increasing. The majority of vineyards were planted in the 1990's and are now reaching full maturity.

The dangers of an early budburst for vines is they are more susceptible to weather damage from frost and wind and hail storms in early spring.

McLaren Vale recieved a hail storm on Sunday the 16th of August with 20 minutes of heavy falls in Kangarilla and along Range Road. The good news is no damage has been seen from this hail storm.

Hail damage shows up as torn leaves and pitted stems.

Tuesday, August 18, 2009

Irrigation Readings - Winter 2009

Some good news from Richard McGeachy - Viticultural consultant.

At the moment the soil moisture is looking substantially better than it was 12 months ago. This plot (below) is take from a moisture monitoring site just to the west of Willunga.

Click on the graph for a larger image.

Clearly soil is much wetter than last year. This is a result of higher than average July rainfall and therefore more moisture making it past 1.0 metre in the profile. This winter has push moisture much deeper into the subsoil than last year.

Thus far August has not offered too much rain to back up July and ideally close to average rainfall through Spring are needed to maintain the current moisture levels.

We’ll be keeping an eye on both the soil moisture and rainfall in the coming months and will make decisions well before flowering as to whether we apply any top up irrigation.

Thursday, August 13, 2009

Rust Mite - UPDATE 13/8/2009

Research over the past five seasons has lead to a better understanding of the causes of restricted spring growth symptoms sometimes experienced in our basin, ones that we used to call cold damage.



Research has shown that these symptoms - shown above - are caused by Rust mite feeding on developing shoots and bunches during the early phase of shoot development. Yield losses have been recorded of up to 30% in other states, but the greatest effect is on evenness of shoot development and thus end fruit quality.

An unbalanced vineyard predatory insect population is thought responsible for high numbers of Rust Mite. If you are seeing this take a look at your spray practices.

Bronzed leaves at harvest are another indicator of high levels of Rust Mite - Below.


Recommendations for prevention of these symptoms are:

• Application of wettable sulphur @ 500g/100lt (include non ionic wetter at label rate if not adding oil).

• Water rates of 600 – 900 lt of water per hectare - do not use less than 500 lt/ha
- increased water rate should be used if worried about coverage.

• Make sure coverage of the cordon and all spur wood is thorough.

• Inclusion of Canola oil or Mineral oil at 2% (2lt per 100 lt) may improve control (10-15%) but should only be applied if the variety being sprayed is fully dormant (eg. Cabernet). Need to be aware that some Canola oils may contain GMO’s.

• A period of 2-3 fine days and 15 degrees C or higher on the day of spraying is ideal.

• Chardonnay is the indicator variety for timing of spraying in each region. Spraying should be done on all varieties when Chardonnay reaches 10% green tip (i.e. most buds woolly bud).

• Our feelings are that spraying should occur from now until the end of the first week of September on all varieties/blocks inthat require rust mite treatment.

Any questions about timings for your specific region please call DJ's for more advice.