Dormant member replying here...
I would like to note that I have experimented with a multitude of different fungicide types:
liquids,powders, sprays, concentrates, herbals etc.
My final 2 favorites ended up being organic products that preformed better than the leading synthetic formulas.
I try to use low impact methods in my greenhouses whenever I can,
and let's just say I'm constantly blown away by the effectiveness of my now favorite systemics.
I'm talking about
Serenade Disease Control, and
Actinovate.
These are organic/systemic fungicides that basically act as very suppressive and impressive "pro biotics" for plants.
The Serenade fungicide utilizes a concentrated solution of a special strain of a bacterial colony (Bacillus subtilus).
Boy does this stuff pack a punch...
It acts as a wildfire "infection" that just gobbles everything harmful infecting a plant.
Not only that, but during its feeding frenzy, it secretes polypeptides which go to work on the mitochondria of your plant leaves.
These essentially spill out structuring stem cell-like resurgences in the vascular and cuticle tissues of the plant cells.
I have seen: bacterial pitting, scarring, light damage, mechanical damage, normally fatal/dire infections, fade away on many a plant from such usage.
Actinovate is something I use less, but bottom line it is a long lasting beneficial mutualistic fungal spore (streptomyces lydicus)
You add it as a liquid root drench to your plants and this little fun guy goes to town!
It comes in a small powder solution that litteraly can be used to save 200+ plants.
The main reason I use it more seldomly, is because I'm not confident with how it acts on other bennifical/mutualistic fungi.
The Serenade however, has a half-life of about 15>30 days. I use it more frequently as my go to solution for:
crown rot, damp off, mold, bio film, mildews, rust and a multitude of other infections caused by protists,bacteria, fungi, and cynobacteria.
I hope this "tldr" is informative