I noticed today while mowing that the tire lines from last week had a fair number of yellow blades on St augustine lawns and red blades on the bahia lawns. It was enough to know exactly where I had mowed last week. worked great for varying my lines, but looked weird. I am tending to think it is lack of water added to the stress from the tires. I only noticed it on lawns that are not irrigated and it hasn't rained here in 2 weeks +/-. It isn't really noticable unless you look down the mow line. Any ideas?