Karen Rane, Plant Disease Diagnostician, Botany & Plant Pathology, Purdue University
It is late summer, and time for the tuliptree (Lirodendron tulipifera), also known as yellow poplar and tulip poplar, to turn yellow and drop leaves (Figures 1 and 2). This unexplained disorder, apparently induced by environmental stress, commonly develops in tulip trees during hot dry weather after midsummer. An added symptom that frequently accompanies the leaf yellowing is the appearance of circular, black spots between the veins of the yellowing leaves (Figures 3 and 4). The black spots are often mistaken for a fungal leaf spot disease. Though alarming in appearance the problem does not affect tree vigor or health.
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Figure 1. Tuliptree with |
Figure 2. Yellow and brown |
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Figure 3. Close-up
of a tuliptree leaf showing physiological leaf spot |
Figure 4. Tuliptree leaves with leaf spot |
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