Common Name: copper spot
Scientific Name: Gloeocercospora sorghi
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Copper spot is a disease of bentgrass species that develops during periods of warm and humid weather. Velvet bentgrass is particularly susceptible to the disease, but it is occasionally observed on creeping bentgrass as well. As the name implies, copper spot appears in small spots, usually less than 3 inches in diameter, that are copper or salmon in color. The disease causes a foliar blight, so distinct lesions or leaf spots are not evident on individual plants. When the turf is wet or humidity is high, the infected leaves may be covered with a thin, gelatinous coating of fungal spores.
Copper spot can often be confused with dollar spot, which produces very similar symptoms. These diseases can be easily distinguished early in the morning when dew is present on the turf. The dollar spot fungus produces white, cottony masses of mycelium on the infected turf, whereas copper spot produces gelatinous masses of spores that are copper or salmon in color. In addition, the outer margin of a copper spot is typically more diffuse than a dollar spot, which has very well defined edges. |