The Moon and Powdery - UPDATE 24/12/2008
The levels of Powdery Mildew have greatly increased in the last two weeks. In most vineyards this is not going to affect harvest as good protection earlier in the season have kept bunches clean.
While the scientist may explain the spread of Powdery by noting recent high humidity and overcast weather which suits the disease, there is another factor that could explain it.
December the 13th was a unique day in the astro calender that Bio-Dynamic farmers follow. It is called a "supermoon" because proxigee (the Moon's closest point to the Earth this year) and full moon occur at the same time.
This combination of a close and full moon causes king tides and other events on Earth. In Papua New Guinea the supermoon produced very high tides that caused dangerous flooding. Closer to home the supermoon's affect is also linked to increasing sap flow in plants. It is also a time for high disease, just as we have seen in the vineyards this week.
Could the gravity effect of a supermoon really cause disease to increase? The next supermoon is January 2010, so lets wait and see if that causes the spread of Powdery!