Needle Blight Caused by Dothistromapini in Austrian and Red Pines in Pennsylvania. B., Towers, Pennsylvania Department of Environmental Resources, Middletown 17057. L. Forer and V. Wagner, Pennsylvania Department of Agriculture, Harrisburg 17120; and W. Merrill and N. Wenner, Pennsylvania State University, University Park 16802. Plant Dis. 68:450. Accepted for publication 29 January 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-450b.
In 1982 and 1983, needle blight caused by Dorhistroma pini Hulb. var. pini was found in plantations of Austrian pine (Pinus nigra Arnold) in Juniata, Lancaster, and Lebanon counties of Pennsylvania and in plantations of red pine (P. resinosa Ait.) in Bradford and Cambria counties. The presence of the disease in small groups of trees in widely scattered areas of the state plus the fact that symptoms resemble those of the common needle cast caused by Ploioderma lethale (Dearn.) Dark. suggest the disease may have been misdiagnosed in the past and may be more common than indicated by these isolated occurrences. The finding of D. pini is significant because of the large numbers of seedlings and ball-and-burlap saplings shipped out of state by commercial nurseries.