If you have been using just one type, Leslie, you should see a BIG difference when you "switch" kinds ! The disease does build up a resistance to the fungicide. I have used 3 different types ( 4,if you count the sulpher spray I do in the fall) alternating , each time I spray. I added another kind to my "rotation" this year, as I was told it was one that showed good results with the botrytis Fungus that I have been battling.
And, while the leaf "tips' are the best indicator (for me, anyway) of a problem with the rhizome.....you can notice that the whole leaf is "off color", and generally un healthy looking.
That's not to say that the bacterial rot can't strike so quickly, that the stalk, or fan falling over is your first sign. It can, and often does ! But, generally, there are some "hints' before the fans actually rot off.
