Thanks all. No, didn't expect it to get rid of damage already there, but there is a new leaf getting ready to pop up and the center growth area looks kind of black or brown as well, and that was my concern. Guess I'll just keep an eye on it and spray a bit less. Down here you can go through a gallon of Physan/SA-20 a month with our heat and humidity, even with pretty good air movement!
Cheers,
Tony