Top is St Augustine. I has a disease which can be cured by applying ordinary cornmeal at a rate of 20 pounds per 1,000 square feet. Get the corn meal at a feed store for around $10 per bag (50 pounds). Give it three weeks and the yellow and brown spots on the blades should be gone. Corn meal is also an organic fertilizer, so expect to see deeper green and more dense turf where you apply it.

Bottom pic is a weed. Could be crabgrass. You can kill crabgrass and not St Augustine with baking soda. Spray the grass first with soapy water and immediately dust with baking soda sifted through a sock or stocking. That will ensure you get only a fine mist of baking soda drifting down to the grass. DON'T inhale the baking soda. Crabgrass will turn black and die starting in a few hours. There are a few other weeds that act the same, so that's why I'm suggesting it.

And no, I'm not a kook. Corn meal and baking soda are tricks you learn on lawn forums. I've tried them both with excellent results.

Thank you very much. I was pretty sure it was St.Augustine and weeds but not positive, I will give both of these a try.