PPDL Picture of the Week
November 5, 2019
Gourd Pointillism
Dan Egel, Clinical Engagement Associate Professor-SWPAC, Botany and Plant Pathology, Purdue University
This is the time of year when many people start to think
about getting rid of gourds and pumpkins in fall decorations. The display in
figure 1 has a gourd with some discoloration. The areas of discoloration might
be an indication that the gourd needs to be thrown out. In fact, the gourd will
continue to deteriorate and rot if left outside.
Take a moment to look a bit more closely at the patterns on
the rind of the gourd in figure 1. The pattern, in a rough circle, is made up
of tiny dots (figure 2). The pattern is caused by a disease known as
anthracnose. Anthracnose is caused by a fungus. Before you throw the gourd on
the compost pile, take time to look at the lesions, some of which appear to be
almost a pointillism masterpiece.
Another option to tossing the gourd out is to let it sit for
a few months in a dry place. When the gourd dries, the lesion growth should
slow or stop. After a few months, you should be able to hear the seeds inside
the gourd when you shake it. Add a coat of varnish if you wish. This should
preserve the gourd and the natural art work for some time. Figure 3 shows such
a gourd on a shelf in the author’s office. Whether you decide to preserve the
gourd or just look it over, now you know more about the pretty pattern that
nature left on your front stoop.