Originally Posted by Ric
Brown Patch is a soil borne disease that has a Fall and Spring Temperature window where it is very active. It like a high pH or alkaline or sweet condition. Non Sulfate Fertilizer help promote Brown Patch because they "SWEETEN" the soil where Sulfate Fertilizers "SOUR" the soil. Potassium will Sweeten the soil while Nitrate will help Sour it. Iron also Sours so your Mix should be just on the sour side.
Sept I start with a Preventative Fungicide as a Blanket treatment. Because my soil is more Calcareous Sand than soil, I deal with a lot of Brown Patch. It is more economical for me to apply a Preventative Fungicide than to fight Brown Patch all winter long.
Sweet = pH up
Sour = pH down
How many apps of preventative do you put down? If more than one, at what intervals?