Xanthomonas translucens pv. poae
Bacterial wilt is characterized by tiny red-copper-colored spots first appearing about the size of a dime. As more plants die, spots become larger. Small, yellow leaf spots, streaked tan to dark brown spots, dark green, water soaked lesions, shriveled blue to dark green leaves, and yellow elongated leaves are all symptoms that have been associated with bacterial wilt. Numerous small, pit-like or speckled spots, about 0.25-0.75 in. (0.5-2 cm) in diameter, may develop on greens.
Bacterial wilt was a major problem on one cultivar (Toronto) creeping bentgrass, but continues to be an issue on annual bluegrass in many regions of North America. Outbreaks tend to occur during extended periods of rainfall. The disease can be devastating if prolonged rainfall is followed by bright sunny days and warm weather. The disease is most devastating where sand top dressing programs are implemented.