When compost is inoculated, working hygienically is vital. The compost has been made selective but the mycelium has not yet developed in the compost, so it is still very sensitive to green mould infections, for example trichoderma harzianum.
Infections can be prevented by observing correct hygiene procedures during inoculation. Cleaning and disinfecting all the equipment and using over pressure in the area used for inoculation are a sound basis for good hygiene.
Measure to be on the safe side, so check hygiene levels by measuring spore pressure during inoculation. Special equipment is available for this purpose, which measures the quantity of spores present. Spore pressure can also be measured by placing an uncovered petri dish filled with an agar extract (MEA) in the room, or by taking a swab with a sterile cotton bud, then rubbing the bud over the surface of the petri dish to inoculate the surface. Any spores present will have developed into cultures on the petri dish after four to five day at 28 degrees Celsius.
This method allows you to verify that clean really is clean!
Mark den Ouden, C point