Disease Note

Endocronartium harknessii on Scots Pine in Massachusetts. K. K. Rane, A. E. Dorrance, and F. W. Holmes, Department of Plant Pathology and Shade Tree Laboratories, University of Massachusetts, Amherst 01003. Plant Disease 69:177, 1985. Accepted for publication 15 October 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-177d.

Scots pines (Pinus sylvestris L, Spanish varieties) scattered throughout two Christmas-tree plantations in Worcester County, Massachusetts, showed stunted growth, twig necrosis, and witches' brooms.  The branches and trunks of these trees bore numerous galls.  Ten percent of the trees in one plantation and nearly 50% in the other were affected.  Sporulation was observed on galls in May 1984.  Spore germination data indicate that the spores were peridermioid teliospores of Endocronartium harknessii (J. P. Moore) Y. Hiratsuka, the causal agent of pine-to-pine gall rust.  The galls on the trunk base of some trees suggested that infection occurred at the seedling state.  Pine-to-pine gall rust was found in May 1959 on mature Scots pines in Chatham (Cape Cod), but this is the first report of its occurrence in Christmas-tree plantations in Massachusetts.

References: Anderson, G. W., and French, D. W. Phytopathology 55:171, 1965.  Hiratsuka, Y. Can. J. Bot. 47:1493, 1969.