Adelaide Hills Crop Watch 271109

CropWatch BERRY SET EL 30 Active shoot tip growth and early berry set. The season is running early and most vineyards are past 80% Capfall and on their way to an early harvest. All seven CropWatch vineyards still have active shoot tip growth, however shoot growth has slowed down in the last week as vines put more energy into developing their fruit. Stuck flower caps have been seen in Shiraz and Merlot blocks (left). This might be due to thrips, water stress or the timing of Capfall relative to the weather conditions we experienced. Stuck caps can cause scaring damage to skins in red varieties (especially Shiraz, Cabernet Sauvignon and Merlot). In general, berry set in Sauvignon Blanc, Shiraz and Cabernet Sauvignon looks good, however low levels of berry shatter have been seen in Pinot Noir, Pinot Gris, Merlot and Chardonnay blocks.

Light Brown Apple Moth Check your developing bunches for signs of caterpillar damage. Look for any flower parts that are stuck together. Apple moth damage is usually found in ‘hotspots’. If you find one damaged bunch like this check other bunches and in nearby leaves for more apple moth activity.

This message from Adelaide Hills CropWatch was compiled for the week ending Friday, November November 27th 2009 and will be updated prior to December December 4th. More Pest and Disease information is available at www.adelaidehillswine.blogspot.com

Powdery Mildew Do not sit back and think that hot weather in the last two weeks means you are totally safe. Assess your vineyard’s risk. Vineyards with a large canopy and a history of poor disease control are likely to have some disease - in spite of hot weather. Do not get caught out – warm, overcast weather and larger canopies due to winter rain have suited the disease. Monitor your vineyard before the Christmas break. Check 50-100 bunches and leaves for any signs like the photos shown on the CropWatch Blog.

CropWatch SA Adelaide Hills is a service provided by the Adelaide Hills Wine Region Inc. DJ’s Grower Services provide vineyard monitoring data, interpret weather data & compile the messages. Information is general in nature and should not be relied upon. Always seek professional advice specific to your vineyard. All photos (c) James Hook & Richard McGeachy unless noted. CropWatch acknowledges the support of James Hook & Matthew Wilson in preparing this message.

Withholding Periods Most vineyards are now past 80% Capfall. Many common vineyard products are now past their withholding periods. Please always read the AWRI Dogbook for grapevine withholdings. Do not rely on product drums and labels, as what is listed on the label is the domestic withholding period! For example SCALA 400SCtm has a 7 day withholding for domestic grapes but an AWRI exporting withholding of 80% Capfall!

GRAPEVINE PRODUCTS THAT CANNOT BE USED AFTER FULL FLOWERING (80% CAPFALL). Name

AWRI Withholding Period Disease

Acrobat

80% Capfall

Downy Mildew- post infection

Polyram

80% Capfall

Downy Mildewprotectant

Prosper

80% Capfall

Powdery Mildew

Chlorothalonil (Bravo, Barrack, Unite etc)

80% Capfall

Botrytis & Downy Mildewprotectant

Filan

10% Capfall

Botrytis

Scala/Pyrus

80% Capfall* *Some wineries have a 10% Capfall restriction.

Teldor

80% Capfall

Mimic, Prodigy

80% Capfall

LBAM

CropWatch SA Adelaide Hills is a service provided by the Adelaide Hills Wine Region Inc. DJ’s Grower Services provide vineyard monitoring data, interpret weather data & compile the messages. Information is general in nature and should not be relied upon. Always seek professional advice specific to your vineyard. All photos (c) James Hook & Richard McGeachy unless noted. CropWatch acknowledges the support of James Hook & Matthew Wilson in preparing this message.

Downy Mildew The weather in the last week was not suitable for a widespread Downy Mildew 10:10:24. All of the weather data we collected showed vineyards drying out Saturday and Sunday afternoons which broke the 24 hour disease cycle. However, in a shock find, we have found Downy Mildew Oilspots in Echunga (right). These were found only in a small area of one vineyard and do not represent a major concern to the rest of the region. How did this happen? Weather conditions in October were close to a Downy 10:10:24 primary infection but our weather stations did not record these conditions. Also most vineyards had shoots that were only 5-10cm and vine canopies were too small to host the disease. At our Downy find at Echunga 10-10-24 conditions must have occurred creating a primary infection event. Microclimate conditions such as longer heavier falls of rain, heavy dews, or external issues such as irrigation leaks can all be contributing factors. Whatever the reason, it was enough to push the Downy Mildew across the line. What does this mean? This patch of Downy does not pose a significant risk of causing an outbreak of the disease. However it is likely there are more isolated patches in the region so be aware. A low risk strategy is to continue to protect your vineyard against Downy Mildew and use a protectant fungicide with your regular Powdery Mildew sprays. If fine, dry weather prevails any Downy oilspots will dry out and eventually become inactive. How do we know there is only a small amount of Downy in the Adelaide Hills? Each week seven different vineyards are monitored as part of the CropWatch services. The weather data is also checked for weather conditions and additionally many more vineyards are checked commercially. CropWatch also communicates with winery and vineyard staff each week to see what they have found. Look for large yellow spots, sometimes with a darker chocolate ring around the outside. Downy spores are easy to see compared to Powdery Mildew and can even be seen from a tractor or a motorbike. It is worthwhile giving all vineyard staff training in monitoring for and recognising Downy. If you have suspected Downy Mildew please use the ‘Bag Test’ to confirm and let us know where you found it.

Above – Downy Mildew oilspots.

CropWatch SA Adelaide Hills is a service provided by the Adelaide Hills Wine Region Inc. DJ’s Grower Services provide vineyard monitoring data, interpret weather data & compile the messages. Information is general in nature and should not be relied upon. Always seek professional advice specific to your vineyard. All photos (c) James Hook & Richard McGeachy unless noted. CropWatch acknowledges the support of James Hook & Matthew Wilson in preparing this message.