In the period of damp, cool autumn and winter as well as early spring, there are conditions conducive to the occurrence of the mushroom fruiting body disease called mushroom rust spot caused by bacteria of the genus Pseudomonas totalis or Ginger.
As the title suggests, the casing plays a major role in the size (diameter) of the mushroom.
The casing is also important to the weight of each individual mushroom. The heavier the cover, the fewer mushrooms, but larger and heavier.
The light cover, on the other hand, means that there are more mushrooms, but smaller and lighter.