Apply as a spray during the heat of mid-day and let dry on the leaf for 12 to 24 hours. The turf appears dark green, with a discoloration of the lower, older leaves. This dark green color of the lower leaves turns to a dull blue-green, followed by a purple discoloration along the entire edge of blade. It is usually more purple on the underside . On some turfgrasses, the purple coloring will change to dull reddish tints that appear on leaf tips first, and then go down the blade.
Dead tissue occurs then on the older leaf tips and progresses towards the base.
Apply at a rate of 1.0-1.25 lbs. Like iron, phosphorous is less available under cold wet soil conditions. Yellowing occurs between the veins, but the mid-vein retains its green color. The leafs may feel limp and soft. The tips of the older leaves my be yellow-white, and be frayed or cracked.