Cotton Root Rot has not killed vines in the Lubbock area. The fungus is most serious on high pH soil. The Texas Grand Prairie north and west of Fort Worth is a very high pH soil and CRR can be expected to kill vines planted in it. Cotton Root Rot moves into young roots and grows between the wood and bark up to the vine crown at the ground line. Once the fungus completely circles the trunk, the vine dies in just several days.
Death is usually just before harvest.
The leaves will turn solid brown with no green color and remain attached. This rapid death is the classic sign of Cotton Root Rot. On high pH sites, rootstocks such as Dog Ridge or Champanel can give some protection. Dead vines can be tested for positive identification at the TAMU Plant Disease Diagnostic Labortory at College Station, TX 77843. Recent vine death in Central, Texas has created serious concern from Fredericksburg north to Denison.