8/14/2019 Adelaide Hills Crop Watch 220110

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CropWatch SA Adelaide Hills is a service provided by the Adelaide Hills Wine Region Inc. DJs 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) JamesHook & Richard McGeachy unless noted. CropWatch acknowledges the support of James Hook & Matthew Wilson in preparing this message.

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Most of the growers in the district have done asteady job in dealing with disease this season.

These growers are on the way to a cleanharvest. There will of course be exceptionswhere patches of vines have some issues(upper and lower left). In these vineyardsPowdery Mildew is spreading.

The weather during early summer suitedPowdery (and Downy). Many growers adaptedtheir strategies to counter this. Those that hadgood coverage, good timingand correct ratesof powdery fungicides have adequate control.

When discussing any disease issuesremember the difference between diseaseincidence and severity.

Disease incidence: The percentage ofbunches infected.

Number of bunches checked =% incidenceBunches with infection

For example: I checked 100 bunches and 3had powdery; the patch has 3% incidence ofdisease.

Disease severity: The area of infectioncovering bunches.

Area of the bunch = % severityArea of bunch surface infected

For example: You have a light (severity)infection of powdery. Only a few spots on the 3bunches I found.

Downy Mildew

The risks of defoliation stopping ripeningcaused by Downy Mildew Oilspots increasingis very low. Downy is unlikely to affect your

harvest because conditions in the last weekhave not caused it to spread. Where we havefound Oilspots they are reaching the end oftheir life and are drying out.

8/14/2019 Adelaide Hills Crop Watch 220110

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CropWatch SA Adelaide Hills is a service provided by the Adelaide Hills Wine Region Inc. DJs 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) JamesHook & Richard McGeachy unless noted. CropWatch acknowledges the support of James Hook & Matthew Wilson in preparing this message.

Early Veraison?

The CropWatch vineyards located throughout the Adelaide Hills have come through the heatwave withminimal damage to the developing crop. Canopies have recorded low to moderate leaf sunburn and somebasal leaves have yellowed and are dropping out of the vine canopy. Some lower leaf yellowing is a normalvine process as leaves only have a limited lifespan (90-120 days). The oldest basal leaves are now in thatage range.

Only bunches exposed to the western sun have any sunburn and this appears minimal.

The heatwave (more than five days above 35oC), seems to have checked verasion rather than bringing iton quickly. Bunches have continued to progress slowly and Veraison has begun in Pinot Gris and PinotNoir. Chardonnay berries are still firm and the growth stage remains Berries Hard and Green(EL 33).

Remember late season withholding periods.

Legendis limited to use 45 days before harvest.

The DMIs: Rubigan, Bayfidanand Myclossare limited to 35 days before harvest. Wettable Sulphur is limited to 30 days before harvest.

Downy protectants are also restricted in their use: Coppers to 30 days, Mancozeb family to 30 daysand Captanto 30 days.

Light Brown Apple Moth & Botrytis

These photos are a good example of what to look for in the next month. There is a strong link betweenLight Brown Apple Moth caterpillars and Botrytis. In the photos below Apple Moth is shown first damagingthe berry skin triggering Botrytis expression (below left), then the Apple Moth caterpillar transfers Botrytisaround the bunch to infect new berries (below right).

While the current dry weather does not suit Botrytis, a good tip is to start looking for Apple Moth and bunchrot now. Train your staff or anyone else entering your vineyard what to look for. If you see the first signs ofBotrytis developing, it is easy to tag the site and monitor it closely as the weather changes.

A low level of Botrytis is not an issue for wine quality and does not affect your yield, however you need tokeep an eye out in case levels start to increase.

GrasshoppersGrasshoppers are still present in and around vineyards however, damage levels remain light. Last weeksheatwave appears to have naturally reduced populations in many blocks.