A Few Leaf Spots Appearing
Helminthosporium melting-out (pathogen Drechslera poae) is becoming more active on Kentucky bluegrass sports fields throughtout the Midwest. Although at the moment it is a minor problem with a few leaf spots appearing, as we progress through the spring symptoms could get worse. This disease initially appears as small leaf spots. The leaf spots have a bleached out center with a purplish border. Overall symptoms appear as a reddish tint to the turf with gradual thinning occurring. The optimum conditions for melting-out are cloudy humid/rainy days when temperatures range from 65 to 75 F. The most effective means of managing this disease is through the use of resistant Kentucky bluegrass cultivars. Cultural practices for minimizing the disease include having adequate, note excessive, levels of nitrogen and reducing the amount of thatch. If thinning or significant loss of the turf occurs, fungicide treatments would be appropriate.