Environ. Horticulture, Pears, Cherries, and Viticulture
University of California
Environ. Horticulture, Pears, Cherries, and Viticulture

Sugar Accumulation Disorder (SAD)

Sugar accumulation disorder (SAD) causes poor berry coloration and low sugar accumulation. SAD is triggered after veraison. SAD-affected fruit typically have lower pH, berry weight, and Brix compared to normally developing fruit. Berries may contain up to 70-80% less sugar than healthy berries and are often shriveled. (Read more...)

Below are photos of Pinot Noir clusters near Clarksburg; the shots were taken Aug. 4, 2015, a few weeks before harvest. Berries on SAD-affected clusters are lighter in color and far less sweet than unaffected clusters. Shortly before harvest, SAD berries will shrivel.

SAD1

SAD2

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