“Take downy mildew seriously in the Adelaide Hills and those sites in on the Fleurieu that are like the Adelaide Hills. Use eradicants if uncovered as spread now will affect grape yield because flowers are highly susceptible to downy mildew.
For McLaren Vale prevent downy mildew building up to high levels like it did in some vineyards last season.”
What does this mean for my vineyard?
You fruit is immune to Downy infection once berries are appx. 2-5mm in size but leaves (and berry stems) remain at risk until harvest.
There is a low risk of Adelaide Hills grape growers losing bunches to Downy Mildew. CropWatch is more concerned about of further warm wet nights through December and January causing a build up of Downy Mildew Oilspots on vine leaves causing defoliation.