Infected vines become nonproductive and often die within 2 to 4 years.
Adjacent vines develop weak, shorter shoots as they are infected by the pathogen.
Dark, rootlike structures, which are rhizomorphs that originate from the vine's root, grow into the soil after symptoms develop on vines. Healthy plant roots can become infected when they come in contact with inoculum, including rhizomorphs, from the preceding orchard crop or nearby oak trees. Flood waters sometimes help spread infected roots in a vineyard. The fungus is favored by soil that is continually damp. The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies.