8/14/2019 Adelaide Hills Crop Watch 050310

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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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Cool overnight temperatures and dews haveslowed down ripening in vineyards across the

Adelaide Hills.

Botrytis bunch rot levels remain low in theCropWatch blocks (right). Look out for anyincreases in bunch mould as some rain isexpected for this weekend. The rain forecasthas been downgraded so hopefully falls willnot split or damage fruit at this late stage of theseason.

Sauvignon Blanc has mostly been harvested.Cropwatchs information has been tonnagesseem to be in line with estimates and are onpar averages season. Localised areas arerecording below average yields; but this was inline with yield estimates taken earlier in theseason.

Chardonnay harvest is also nearly completedand Pinot Gris is being picked with goodtonnages recorded.

Red varieties are still some-way behind,although Pinot Noir for table wine are ripeningsteadily. Titratable acidity levels (TA) seem to

be holding in most samples. Pinot Noir shouldbegin picking next week.

Shiraz, Cabernet Sauvignon and Merlot arelikely to be at least another two weeks awayfrom harvest. Our observations are some sitesmay take until April to reach ripeness if coolweather continues.

Light brown apple moth (LBAM) caterpillarsare still present in bunches, but damageseems to be limited.

Vine Moth caterpillars (lower left) are morevisible at this stage of the season. Adult mothsare also quite commonly seen flying invineyards, although caterpillar levels are

8/14/2019 Adelaide Hills Crop Watch 050310

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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.

Post Harvest Disease control

There is much debate about whether vineyardsshould be sprayed after harvest. Latestresearch would indicate that these sprays areoften not needed.

Powdery mildew - Grape growers becomeconcerned about high levels of Powderymildew on their leaves (upper right).

1/ You might reduce the spread of powderymildew in the canopy.

However, where disease has alreadydeveloped, further increases in levels ofpowdery afterharvest generally make little

difference to leaf and vine health.

2/ You might aim to reduce the amount ofdisease for next season.

Unfortunately spraying after picking has littleeffect on the risk of Powdery mildew next year.

Most buds that survive to next season aresusceptible to powdery only in early growingseason, so spraying now will not affect levelsof winter-carryover in the buds. Also, thefruiting bodies of powdery, called cleistothecia,are somewhat like apples on a tree, they ripenin late summer and autumn. Sincecleistothecia have already matured in mostvineyards by now, post-harvest sprays are toolate and do nothing to reduce their numbers.

Rust mite - Spraying for Rust mite afterharvest is not recommended. The Rust mitebronzing to leaves you see are not doing anydamage to your vine leaves and they functionnormally (center and with slight blister mitedamage also seen lower right).

If you have bronzing on your leaves, recordthis as it is the threshold for a rust mite spraynext spring. Spraying in spring 2010 isrecommended if uniform, moderate to highbronzing is obvious in your vineyard now(March 2010).

A spring spray aims to reduce the rust mitepopulation down to a level where predatorymites can then maintain effective control.However, this approach does have some

toxicity to predators therefore, using it when itis not needed can damage predatorsunnecessarily!