Greater Diversity of Vegetative Compatibility Groups of Cryphonectria parasitica on Scarlet Oak than on Post Oak in North Carolina. B. L. Nash, Former Graduate Student, School of Forestry and Environmental Studies, Duke University, Durham, NC 27706. W. J. Stambaugh, Professor, School of Forestry and Environmental Studies, Duke University, Durham, NC 27706. Plant Dis. 73:416-418. Accepted for publication 12 December 1988. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0416.

The distribution of vegetative compatibility (v-c) groups of Cryphonectria parasitica on cankered post oak (Quercus stellata) and scarlet oak (Q. coccinea) was investigated in North Carolina. Of 37 separate cankers on 12 post oaks, 35 had one v-c group and two had two v-c groups. The groups were the same or differed among cankers on single trees. On scarlet oak, several different v-c groups were present within small portions of infected butt sections. The number of different v-c groups within single scarlet oaks varied from one to five. Distribution patterns of v-c groups were not predictable, even among trees located close to each other.