Ascochyta Blight is a common but minor turf grass disease. Kentucky bluegrass and perennial ryegrass are the most common grasses in our area. They are very suscepticble to attack from certain species of the fungus Ascochyta.
Periods of wet weather or frequent watering favor Ascochyta, which survives in the thatch layer of lawns. The grass leaves are effected especially during late spring and early summer. The fungus enters through freshly cut grass leaf ends and grows at the base of the leaves. Frequent mowing, particularly with a dull mower blade, increases infection.
Ascochyta Blight may cause large areas of turf to appear off color but it may also appear only in localized patches. Indiviudal leaves die from the tip and take on a bleached color, resembling injury from a dull mower blade. 
Ascochyta blight injury is seldom extensive, so control measures are rarely necessary. No fungicides are registered specifically for use against Ascochyta blight; yet, most broad spectrum turf grass fungicides will provide some amount of protection.
Recommended Treatment:
1. Sharpen Mower Blade
2. Water 1-1 1/2 inches water weekly
3. Raise mower height
4. Lawn will recover after 3-4 mowings.