VIEW ARTICLE

Interaction of Cronartium fusiforme and Cronartium quercuum with Quercus velutina. L. David Dwinell, Plant Pathologist, Southeastern Forest Experiment Station, USDA Forest Service, Forestry Sciences Laboratory, Athens, Georgia 30601; Phytopathology 61:1055-1058. Accepted for publication 2 April 1971. DOI: 10.1094/Phyto-61-1055.

Cronartium fusiforme interacted differentially with black oak (Quercus velutina), whereas C. quercuum developed normal uredia and telia. The types of infection observed were similar to four of the Puccinia graminis types (0, 0;, 1, and 4), and were not influenced by the age of host leaves. Half-leaf inoculation tests of lots of aeciospores and urediospores of C. fusiforme and C. quercuum showed no variability between rust collections within a species. Therefore, black oak seedlings of known resistance to C. fusiforme infection (types 0; and 1) can be used to differentiate between C. fusiforme and C. quercuum.