Gray Leaf Spot

 Recently I have been fielding significant questions and concerns from Panther Creek members regarding the intermediate grass (i.e. the first cut and surrounding rough) throughout the property and especially around greens.  Multiple factors have contributed to the decline and turf loss that is evident in these areas of the course, symptoms of which began to arise after Labor Day. 

The biggest contribution to the decline was a severe outbreak of Gray Leaf Spot on our Ryegrass population within the intermediates.  Gray Leaf Spot is a devastating disease on Annual and Perennial Ryegrass during periods of prolonged excessive heat (82-90+), humidity, excessive rainfall, and highly fertilized turf stands.  The disease pathogen is rapid and can easily spread with rain, wind and mechanical traffic.

Although preventive measures were utilized throughout the season with our chemical program (some intermediates are included in fairway and green sprays), the rainy weather leading into the 5 day stretch of heat (above 90) and humidity caused an outbreak. Once identified, we applied a curative application to the affected areas in hopes of limiting the severity of outbreak, unfortunately, the conditions, and continued rainfall following these weather patterns did very little is stopping the infection.

Annual and Perennial ryegrass cultivars vary in their susceptibility to gray leaf spot, although none can be considered completely resistant. The disease does not affect creeping bentgrass, annual bluegrass, and Kentucky bluegrass. Over-seeding with Turf-Type Tall Fescue, or Kentucky Bluegrass is recommended for repairing perennial ryegrass stands killed by gray leaf spot. We have been over-seeding with a Turf Type Tall Fescue mix called Winning Colors which is a mix of several award winning fescue varieties.