Wednesday, October 28, 2009

Powdery mildew has been found - UPDATE 28/10/2009

The first signs of Powdery Mildew for Vintage 2010.
The first signs of Powdery mildew have been seen in the last 10 days.So far these have been minor, however small Powdery mildew infections before flowering can turning into large problems at harvest.

Powdery mildew doesn’t need rain to spread - mild temperatures (20 – 29oC) & cloudy conditions favour the disease. In these conditions powdery rapidly produces spores and spreads on to unprotected leaves and bunches.

Be careful this season as weather conditions this spring have been favourable to the disease. Based on what we have seen in vineyards we feel Powdery mildew pressure is higher than last season.

Powdery has been found in two commercially monitored blocks, one block has a history of the disease, the other has been very clean up until now. The good news in most vineyards no Powdery has been found. On blocks with a bad history of disease, where growers have been running good protective spray plans for a few season vineyards the vineyards seem clean.

Powdery mildew prevention has effects over many seasons. Good control last season makes control easier this season. Good control this season makes future control easier by reducing the amount of disease that survives winter in the vineyard.

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