There is little light on the forest floor, but virtually none in the debris. The light that reaches the forest floor, through the leaves is rich in blue light. That is true because the chlorophyll in the tree leaves remove most of the red light and blue light is favored by the the scattering as it comes through the leaves. Growers could conserve energy by using lights that produced only the blue light that the mushrooms need, but special lights are expensive and other light is needed for monitoring the crop and for picking. “Cool white” or “daylight” fluorescent lights are adequate for all of the growing room needs and are readably available at reasonable prices. With those lights used about 12 hours each day and with only enough to just be able to read a newspaper at the growing surface, there will be plenty of light to produce high quality mushrooms. Incandescent lights will not allow production of quality mushrooms.

Picking and packing techniques

     The timing of picking is important, but the techniques of picking are also important. Mushrooms must be given a little twist and then pulled, not cut from the growing surface. The consumer will not know if they are cut from the surface or trimmed after pulling, but Trichoderma and other diseases will appear on the cut surfaces, left on the substrate. So the quality of future harvests will be affected.

     Another important condition is cleanliness. Pickers must have clean hands or gloves. Better they should have clean hands and fresh latex or plastic gloves. Pseudomonas tolaasii is particularly a problem during picking when careless or untrained pickers can easily spread it. Mushrooms that turn yellow in the stores will injure the grower's reputation and the store's. Packing is the next place where Pseudomonas may be spread. The photo on this page shows a bad example from a careless operation.

     As quickly as possible after picking, the mushrooms should be cooled to 4ºC (39ºF) and kept that way (wholesalers and retailers note). Ideally, the initial cooling should be done by placing the mushrooms in a vacuum.

     Mushrooms for the retail market should always be protected from mistreatment. The standard way to accomplish that is by use of a plastic or paper tray, over-wrapped with plastic film. Large restaurants will not wish to bother with small packages, but they are also less likely to damage the mushrooms in handling.