Source: Texas Plant Disease Diagnostic Lab
Cotton Root Rot (CRR) occurs on wine grapes in the calcareous soils of Central, South, and West Texas where soil pH is well above 7. The most common symptom of CRR in grapes is a sudden wilt and death of the infected vine. All of the leaves on the vine usually turn yellow and quickly become brown and dry.
There is a fungicide called TOPGUARD® Terra to treat CRR. It is now available for wine grape growers to use in their vineyards.