Competitor moulds are fungi that eat the same straw as your crop. Green mould (Trichoderma), ink caps (Coprinus), plaster moulds and yellow moulds are the common ones. DMR reports yield losses of up to 70 percent in oyster from competitor moulds.
Each has a cause upstream. DMR's table lists green mould with low pH and immature spawn, ink caps with ammonia, old wheat straw and too much moisture, and olive green mould with pasteurising above 60 degrees. Fix the cause and the mould stops returning.

