Heavy rain on the evening of Sunday the 20th of March has been ideal for Botrytis Bunch rot. Very high humidity in vineyards has seen an increase in Botrytis - with fresh sporulation seen. In some cases Botrytis has appeared in vineyards that were clean at the end of last week.
Above and Below - Heavy bunched Shiraz and Chardonnay has suffered from a large increase in the about of Botrytis in the last 24 hours.
In many situations vineyards will need to be picked as soon as possible, or the fruit will not be sound for harvest. If fruit is close to harvest ripeness then it should get 'over the line', the main concern is for vigourous Shiraz vineyards and Grenache in McLaren Vale, The Barossa and Langhorne Creek, plus any white grapes that haven't been harvested yet.