[xolox]

I grow mushrooms as a hobby and in that context my number one enemy is trichoderma, the green mold. This is because trichoderma is parasitic on other fungi, i.e. it doesn't colonize the substrates that I grow my fungi on, it directly colonizes (eats) the fungal threads (mycelium) thereby killing it off before it has a chance to "fruit" (produce mushrooms).

This is how I initially learned that trichoderma is used as a natural "fungicide". In your specific case it might be interesting to investigate this in more detail, e.g. you can "inoculate" your soil with copious amounts of trichoderma to fight off other fungi.

For more details here's a pointer to a rabbit hole: https://www.google.com/search?q=trichoderma+fungicide

Sorry if you know all of this already, I was hoping it might help :-).