Thursday, January 29, 2009

Day 2 of heatwave has caused sunburn on leaves and fruit

Shiraz grape berries shriveling.
Leaf cupping.
Cupped and scorched leaves have been seen. Some fruit is showing signs of shrivel like it can before harvest, however the fruit is only 9-10 oBe.

The most significant sunburn has been seen on blocks that face the western sun and have sandy soil which reflects heat back into the canopy. We need to wait until the hot weather passes to see how the vines will re-hydrate and resume 'normal' ripening.

In the medium term post harvest care of vineyards takes on an increased importance. Vineyards have experienced tough, dry growing conditions for 3 out of the last 4 years (2007, 2008, 2009). Many vineyards have been reduced in vigour compared to 2006. If this trend of devigouration continues vines will reach a point where they are too weak for quality fruit production. A drive around McLaren Vale will show some vineyards at this point already.

Play close attention to your vines after harvest, the heatwave will pass, and the condition of your vines will play a large part in future vintages.

Leaf scorching.

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