Photo Quiz: Suspicious shadow, patchy pattern on green

A shadow without sun, a series of off-color patches — try your hand at determining what caused this pair of peculiar occurrences.


Filed to: Photo Quiz

GCM’s Photo Quiz is presented in partnership with STEC Equipment.

STEC Equipment

Problem A: Mark in the shape of a flag on a cloudy day

Cyanobacteria turfgrass
Location: Smethport, Pa.
Turfgrass area: Putting green
Turfgrass variety: Bentgrass/Poa annua

Problem B: Intermittent off-color areas

Yellow patches turf
Location: Malaysia
Turfgrass area: Putting green
Turfgrass variety: Tifdwarf bermudagrass

Scroll down for answers.












Problem A: Mark in the shape of a flag on a cloudy day

Algae golf course

After a nearly inch-and-a-quarter downpour the previous night, the golf course superintendent at this property was touring the course and noticed several flagsticks had blown out of their cups. The greens are push-up greens dating back to 1926, and after picking up this particular pin, he noticed the perfect pattern in the exact image of the pin and flag on the green. It looked like a shadow from the flag and pole.

Upon closer inspection of the pattern, the superintendent discovered algae had grown where the stick had been lying all night. There was also some residue on the pole.

According to John Kaminski, Ph.D., of Penn State University, low light, high moisture and any sort of covering allows algae (actually cyanobacteria), if present, to bloom. It is common under green covers and is usually caused by low light. However, because this occurred overnight, he suspects the algae — which lacks true stems, roots, leaves and vascular tissue — may have just been reaching out for a surface to cling to so it could elongate itself for light. There was still a faint shadow left on the green after mowing, but it was gone following the subsequent mowing.

Photo submitted by James Askey, the superintendent at Smethport (Pa.) Country Club. Additional information provided by John Kaminski, Ph.D., of Penn State University.

Problem B: Intermittent off-color areas

The intermittent, off-color areas on this green were caused by an exhausted mower operator. This 18-hole golf course in Malaysia has only one walk-behind mower for all 18 greens, and one person mows all the greens. Because this was the last green to be mowed, the turfgrass consultant thinks the mower operator was so tired on this day that they were leaning backward as they mowed. This caused the machine to jump and scalp in this pattern. Some additional thatch could have also contributed to the interesting pattern. It took a couple of days, but the turfgrass eventually grew out, and the green recovered.

Photo submitted by Normas Yakin, a turfgrass consultant in Malaysia.

Editor’s note: Have a photo for Photo Quiz? Email it to author John Mascaro.

John Mascaro is the president of Turf-Tec International.