THE CASING LAYER

velutipes Lentinus edodes Lepista nuda PI, ostreatus PI. ostreatus (Florida variety) Pan. c /anescens Pan. subbalteafus Ps. cubensis Ps. cyanescens Ps. mexicana Ps. tampanensis S. rugoso-annulafa [/. volvacea 

In all species where the use of a casing has been Indicated as optional, yields are clearly enhanced with the application of one. The chart above refers to the practical cultivation of mushrooms in quantity. It excludes fruitings on nutrified agar media or on other substrates that produce but a few mushrooms. Consequently, casing has become an integral part of the mushroom growing methodology. 

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The enlargement of a pinhead into a fully mature mushroom is strongly influenced by available water, without which a mushroom remains small and stunted. With the casing layer functioning as a water reservoir, mushrooms can reach full size. This is particularly important for heavy flushes when mushrooms are competing for water reserves. 

The casing layer must maintain mycelial growth, stimulate fruiting and support continual... 

Oyster Shell Comprised of calcium carbonate, ground up oyster shell is similar to limestone grit in its buffering action and its structural contribution to the casing layer. But oyster shell should not be used as the sole buffering agent because of its low solubility in water... 

Evenness The casing layer should be applied as evenly as possible on a level substrate surface. An uneven casing depth is undesirable for two reasons shallower regions can... 

Although the casing layer must be even, the surface of The casing should remain rough and porous, with small "mountains and valleys". The surface structure is a key to optimum pinhead formation and will be discussed in more detail in the next chapter. 

Moisture within the casing layer has a direct effect on the diameter and degree of branching in growing mycelium. These characteristics are indicators of moisture content and can be used as a guide to proper watering. 

Equipped with a basket and short bladed paring knife, grasp the base of the stem, and with a twisting motion, pull the mushroom from the casing layer being careful not to disturb neighboring pinheads. 

Mushrooms growing in clumps or clusters should be broken apart and harvested individually when possible. Special care must be taken with those clumps containing both mature and immature mushrooms. Leave immature mushrooms attached to the casing layer or substrate to insure continued growth. 

Pseudomonas also contaminates agar and grain cultures, inhibiting mycelial growth. The use of antibiotics (gentamycin sulfate) or micron filters prevents outbreaks of this contaminant. A few species cause the mycelium to grow more rapidly and luxuriantly. Similarly, considerable attention has centered on the beneficial role of Pseudomonas putida and allies in the casing layer. This subject is discussed in detail in Appendix II. 

Common on fresh manure especially on compost that has been anaerobically pasteurized refuse materials straw "leaf mold" soils plant debris paper products and cloth Chaetomium fabric. Chaetomium is a rare contaminant of grain and is infrequently seen in agar culture. A white species occurs on the casing layer. Medium Through Which Contamination Is Spread Air soil compost and grain. 

At lower infestation levels, larvae migrate into The casing layer and then emerge just as the first mushroom pins appear or as late as the first flush. These adults lay more eggs in the casing, and the newly hatched larvae attack both mycelia and mushrooms. Symptoms of this attack include ... 

Plate 22 Trichoderma.ihe Forest Green Mold, contaminating the casing layer. 

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