Hmm. Switzerland where atrazine came from banned it for 15 years. I may be wrong with numbers but Germany and Italy have banned it since 1991 so almost 20 years. I guess that tells you something... Supposedly toads are very sensitive to them so that explains why I never saw them anymore in large numbers. As a little kid, I'd see hundreds of toads mating with each other in the outdoor pond. All of suddenly, I see very few of them since then. I wonder if Atrazine/pesticide had to do with that.

I was just reading the label for Ortho Weed-B-Gone for Southern lawns printed here. It says it is safe for St Augustine except Floratam. Also there is this professor from Florida that states that the problem with 2,4-D is that it gets mixed with mecoprop and that the mecoprop does the damage to St Augustine. Scroll down to the third paragraph in the SpeedZone section near the bottom of the page.

When you say 24-D, you must have meant 2-4-D, which is a broadleaf herbicide, not a fertilizer. From the pics, I see a couple of nutsedge (a weed) and a lot of Bermuda grass. You can get rid of the nutsedge w/ an herbicidde like Sledgehammer. Getting rid of the Bermuda though is gonna be tough. You could mow your St. Augstine at the highest setting and that will shade out and slow the spread of the Bermuda. I'm not aware of any herbicide that will kill Bermuda w/o killing everything else in your yard. If you could take a picture that showed a wider shot of the lawn, that might be more helpful to get a sense of what you're up against.

That is not crabgrass, but this will likely work anyway. Most grasses are very intolerant of salt. St Augustine, on the other hand, will grow out into the surf. So here's what you do. Mix enough molasses and shampoo into a hand spray bottle so that when you spray it on the weed, that the water sticks and does not bead up. I'd start with 3 ounces of each and 16 ounces of with water. Put some baking soda into a sock or hose. This does not ruin the sock or hose, so just find one and use it. Spray the weed with the spray and pat the sock over top of the wet weed so the dust falls out and sticks to the moist blades of the weed. The sock is just a filter so you're not dropping clumps of baking soda. Be careful not to get the baking soda dust in your eyes or lungs. You can build it up reasonably thick. Sit back and watch the magic happen. Actually it does not happen before your eyes, but in 3 days the weed should be black and dying. It's a very satisfying thing to behold. I don't remember the name of the product that this "recipe" came from. It was developed in FL about 10 years ago and was published before they took it public. When they took it public they added cinnamon and called cinnamon the active ingredient. I believe that was to hide the fact that they are charging $10 for $0.30 worth of baking soda.