Category Soilborne Diseases Subject Avocado Root Rot (Phytophthora cinnamomi) Title Avocado Root Rot (Phytophthora cinnamomi); visual symptoms Description Avocado root rot, beginning of dieback, no fruit. Stage 4 of Zentmyer rating scale. Co Var Orchard, Santa Barbara, CA. Location Santa Barbara, CA Date December, 1969 Source George E. Goodall Larger Picture 1000 x 671 (91 kb)