My name is Marcos, maybe I’m the only Agaricus grower and brazilian here, but I think my experience might help someone. I’ve just watched blotch 2.0 episode and I want to share one solution I practice for about 2 years: PCC (precipitated calcium carbonate).
The principle is not to kill the bacteria, but to feed the mycelium with calcium (which in theory makes it more resistant, you can even feel the mushroom is more firm) and prevented the water on the mushroom surface to become acidic. From what I learned with other growers here in Brazil, the toxins produced by some bacteria do not “work well” on buffered solutions.
Today I apply 0,5g of PCC per liter of irrigation water. But 90% of the blotch control (for me) still is ventilation and humidity management…