Friday, January 29, 2010

Weevils - look out in Kuitpo vineyards



Garden Weevils are being found in Kuitpo. They are being found in canopies and bunches.

Adult weevils emerge from the soil in mid to late October and are most numerous between November and December. Many adults survive until April with some being present through winter. Adult garden weevils attack foliage, buds and fruit. Grapes can be scarred, while leaves usually have distinctive round holes and ragged edges. Adult weevils can weaken grape bunches by ringbarking the stalk – so look out for bunch damage in the coming weeks.

Thursday, January 28, 2010

C Grade


Why we consider this vineyard to have a lower quality in the field.
1) Short shoots which haven't lignified and have bunches on them ripening slower than the main crop (below).
2) More shaded fruit; especially on the lower cordon.
3) Moderate to large berry size.


A/B Grade Shiraz.


What we consider to field grade an A/B Grade.
1) Open canopy with good light exposure.
2) Even fruit development - all bunches ripening at the same rate.
3) Fruit all on main 'count' shoots which have lignified up. No short shoots with fruit.
4) No sunburnt fruit or fruit that is mushy or cooked.
5) Healthy functioning leaves.
6) Small to moderate berry size.

Vine Balance - A/B Grade Shiraz Photos

Above- Shiraz this week has fully coloured and completed verasion (EL 35). Note the dappled light on the fruit.
Below- Balanced Shiraz at harvest (2004 Vintage).


A vine can be described as ‘balanced’ when vegetative growth and fruit load are in equilibrium. Other indicators of balance include early maturity, ability to store good reserves of carbohydrate, low shoot variability and cessation of shoot growth by veraison. In order to achieve balance in the current season, vines must have an adequate number of active leaves (shoot to fruit ratio) to sufficiently ripen fruit.

Vine balance can be assessed by a number of methods. The most common is the measurement of fruit weight to pruning weight ratio. Balanced vines have a pruning weight ratio in the range of 5 to 10:1(Dry et al, 2004).

The second method is the measurement of active leaf area per gram of fruit, expressed as cm2/g. The optimum active leaf area for balanced vines varies and may range from 6 to 25 depending on variety, climate and trellis type. For cooler climates such as McLaren Vale, vines may be considered balanced if leaf area per gram fruit is between 12 and 15 cm2/g2 (Winter and Whiting Aust. Viticulture Jan 2004pp 70-73).

Wednesday, January 20, 2010

Botrytis

The first signs of Botrytis bunch rot were found yesterday by James and Sam. In both cases the fruit had been damaged and Botrytis had developed. The photo (above) shows the link between Light Brown Apple Moth caterpillars and Botrytis. In this case the Apple Moth had damaged the berry skin triggering Botrytis expression, then the Apple Moth caterpillar has transferred Botrytis around the bunch to infect new berries (below).

Tuesday, January 19, 2010

Bunch Powdery Mildew in the Adelaide Hills - ID Photo


Matthew Wilson reports from the Adelaide Hills - Cooler weather this week has allowed the continued spread of Powdery Mildew (above). Some blocks throughout the district are now presenting very high levels of bunch powdery. Heavy canopies have provided ample protection and cover for powdery to flourish. Most leaf infections have been controlled, but in many cases, bunches deep within the canopies are still showing devastating levels of active powdery mildew (below).


Buttshoot removal and leaf plucking are being employed in some chardonnay blocks. This helps increase fruit exposure and airflow which can naturally help control powdery. Low levels of bunch powdery is now being detected on bunches in Sauvignon Blanc blocks. There is still time to control this effectively, before withholding periods limit control strategies.

Monday, January 18, 2010

Sunburn is drying out and shrivelling up.

Sunburnt fruit from last week is drying up (above) and will drop out before harvest. This fruit should not affect the quality of your harvest - although some yield loss will have occurred where high amount of sun scorching and heat damage have occurred.

Vines have survived the heatwave of 2010 in much better condition than the late January heatwave of 2009. Be alert for further heatwaves and try to get as much water into your subsoil as possible in the days leading up to the heat. Anti-stress or sunscreen products may help but seek your wineries permission first before applying.

In the medium term post harvest care of vineyards takes on an increased importance. Vineyards have experienced tough, dry growing conditions for 4 out of the last 5 years (2007, 2008, 2009 and 2010). Many vineyards have been reduced in vigour compared to the middle of this decade 2005/06.

Wednesday, January 13, 2010

Heat and sunburn - ID Photos

Heatburn has been observed on some vineyards. Only a small percentage of fruit has been burnt (turned pink). This will turn shrivel, turn hard and fall out of bunches before harvest. The heat also scorched leaves as shown (below).

Scorched leaves from high temperatures in the vineyard.
However despite the high temperatures vines are in better condition than Vintage 2009. Good news.

Monitor soil profiles to ensure they have adequate soil moisture before and during any further heatwaves. Experience from Vintage 2009 showed that it was best to water before heat stress rather than during heatwave conditions.

Remember vines use the most water during veraison. Avoid water stress to vines when berries soften and colour. Do not perform RDI (regulated deficit irrigation) during veraison.

Monday, January 11, 2010

Climate change article from the Age Newspaper.

Grape growers first to harvest a bunch of changes

JENI PORT - January 10, 2010

''SNOW'' Barlow's 2010 vintage is still an idea, the wine grapes formed but not ready to turn in colour or give up fleshy juice.

Two months after flowering and still in a dreamy pre-pubescence, they're about to get a nasty awakening, a major test of stamina, with temperatures destined to hit about 40 degrees today and tomorrow in Central Victoria.

Professor Barlow's Baddaginnie Run Wines and Seven Sisters Vineyard, 24 hectares of vines set against a backdrop of granitic outcrops that make up the Strathbogie Ranges north of Melbourne, are already feeling the effects of an unusual burst of hot weather that occurred in early November.

The dams are evaporating fast, and water is rationed to sustain some grapes through to harvest. Others will have to fend for themselves.

Recurring extreme weather, the face of climate change, is altering the nature of Victoria's - and Australia's - wine-grape harvest.

The harvest is coming earlier; for many regions, it's now in the middle of the hottest month of the year, February.

For the past four years, it has also come with a rush, often catching winemakers off guard and reducing the picking period to mere weeks instead of a few months. Any distinction between early-ripening grape varieties and late-ripening varieties at times seems barely to exist.

Professor Barlow and his partner, former Greening Australia chief executive officer Winsome McCaughey, have catalogued the changes in their vintage conditions since 1995, the year they planted shiraz, cabernet, merlot and verdelho.

That was also the year in which the region recorded its last ''average'' rainfall of 69 centimetres.

But with his daytime work hat on, Barlow - professor of horticulture and viticulture at the University of Melbourne - has also been cataloguing vintage climate data in wine regions across the country.

He has studied climate change since 1982 and oversaw the first major research work into its effects on Australian viticulture in 2006.

But the initial results of this latest study, yet to be completed, have already shocked him. At the start of 2009, his research team set out to find out just how far forward vintage had come in winemaking regions.

In one instance, the harvest of pinot noir at Main Ridge on the Mornington Peninsula had come forward 40 days in 40 years. For chardonnay grown on the same vineyard, picking dates were 32 days earlier than they used to be.

At Tahbilk, one of Victoria's oldest vineyards with vintage climate data going back to 1932, Professor Barlow's team found picking days had fast-tracked over the decades by 20 days. ''Unbelievable,'' he says.

Early data appears to be outstripping 2006 computer modelling, which predicted that harvest in areas such as the Riverina would be six to 12 days earlier than now by 2030 and between seven to 14 days earlier by 2050. Increased carbon dioxide in the atmosphere appears to be an important factor.

''It does help plants photosynthesise quicker,'' says Professor Barlow, ''and we are just wondering if you have the same amount of fruit [on a grapevine], the same amount of leaves and those leaves work harder you might get there [to harvest] quicker.''

Professor Barlow believes Australian winemakers are at the forefront of climate change detection - ''the canary in the coalmine'' as he puts it - because most growers religiously catalogue details of their year: temperatures, picking dates, sugar and acid readings, soil moisture tests.

He notes that he rarely meets a climate change sceptic in the wine industry.

Wednesday, January 6, 2010