Gray leaf spot

Gray leaf spot can be a very damaging disease. It affects tall fescue and ryegrass predominantly, which are our two most prevalent rough grasses. Unfortunately, conditions were ripe last week, and the disease did some damage.

An up-close shot of an individual leaf blade
and lesion

Gray leaf spot is named for the gray/tan/orange lesions that appear on affected plants. These lesions slowly grow if left unchecked and the individual blighted turf can turn into a patch of diseased turf.

Prolonged leaf wetness, heat, and humidity are the leading factors in developing an outbreak. Improper irrigation timing, rain, or mornings of heavy dew and cloud cover leave the tissue wet, and then the heat and humidity later in the day lead to infection. Once one plant is infected, nearby plants can become sick quickly, which leads to the patches of disease.

Unfortunately, newly seeded grass is especially susceptible. For us, this means that several areas of new seed in the collars that had started promisingly, were quickly killed by gray leaf spot. In addition, several established areas that had survived all the other trials of the summer, were also quickly infected.

A gray leaf spot disease patch

Although we do spray fungicides preventively against this disease, the conditions overcame our chemicals. Also, the new seedlings had just begun to grow and were not germinated during the previous chemical application, so they had no protection, and our next application was a few days away. We could have sprayed sooner to provide protection to the newest grass; however, rain prevented the application (the same rain that provided unnecessary leaf wetness that spurred the disease).

We will reseed the worst areas again. We use seed that is bred to be resistant to gray leaf spot and it does well under moderate conditions. Nevertheless, when conditions progress to severe, the pathogen can overtake the inherent resistance and still cause damage.

Another patch

Though this was a setback to our recovery from summer, it is not devastating. We were able to identify the problem and halt its spread. We will bounce back and continue working to get conditions back to normal.

Etiquette Reminder of the Month

When you splash bunker sand onto the green after your shot, please brush away any large piles or clumps that may have ended up on the green.

Also, as part of a Golf Committee initiative to improve course etiquette, we have included links to videos teaching proper on course etiquette. Please take a moment to watch:

Ball Marks - How to properly repair

Bunker etiquette

 

 

See you on the course!

Joe

jvillegas@bwrc.org