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The P&PDL Picture of the Week
for 1 December 2003

Sphaeropsis Tip Blight

Karen Rane, Plant Disease Diagnostician, Purdue University

The dead lower branches in these Austrian pines (Fig. 1) are due to Sphaeropsis tip blight (formerly called Diplodia tip blight). The causal fungus infects newly elongating shoots, in late spring, resulting in stunting and death of the new growth (Fig. 2). Black spore-bearing structures of the causal fungus, similar in size to a period on this page, are formed at the base of the stunted brown needles. Austrian pines are very susceptible to the disease, and infected trees often lose ornamental value as twigs are killed year after year. For more information on this disease, refer to BP-24-W, which can be found at: http://www.ces.purdue.edu/extmedia/BP/BP_24_W.pdf

Click on the small image to view a larger image.

Figure 1. Mature Austrian pine trees
with dead lower branches
due to Sphaeropsis tip blight.

Photo courtesy of Karen Rane

Figure 2. An elongating shoot which
was killed by Sphaeropsis tip blight
(Note stunted dead needles).

Photo courtesy of Gail Ruhl,
Interim P&PDL Director

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Last updated: 1 December 2003/amd
The Plant & Pest Diagnostic Laboratory at Purdue University