SB 353 .B75 Copy 1 P?e CULTIVATED MUSHROOM PRICE, ONE DOLLAR COPYRIGHT. 1913 BY Bureau of Mushroom Industry Chicago. U. S. A. Published and Copyrighted, 1913 by BUREAU OF MUSHROOM INDUSTRY' 1.U2 North Clark Street Chicago, V. S. A. MUSHROOM Q \B ai PRICE, ONE DOLLAR COPYRIGHT. 1913 BY BiiRKAU OF Mushroom iNnrsTRv riiicAr.o, U. S. A. ILLUSTRATIONS 3S. C ^^ Page 1 . Frontispiece • 1 2. The Cultivated Mushroom 3 3. Small Growing Cluster 7 4. Agaricus Campestris, Brown (Bohemia) 11 5. Agaricus Campestris, Cream 15 (). Ventilator ■ 16 7. Agaricus Campestris, White (Alaska) 19 S. Ridge Beds in Cave or Tunnel 22 9. A Flat Bed in a Barn 23 10. Shelf Beds in Cellar 24 1 1 . Flat Beds in Cave or Tunnel 25 12. Coprinus Comatus 32 13. Cluster of 50 Mushrooms on One Root 33 14. Baskets of Large Mushrooms 34 15. A Bed of Over 2 Lbs. per Sq. Ft 35 10. vShipping Crate 36 17. Pure Culture Brick Spawn 43 18. Bed of Mushrooms from Old Spawn 44 19. Mushroom House partly Underground 47 20. A Large Mushroom Plant 48 21. Mushroom Fly 72 22. Steaming Box 74 23. The Mushroom Mite 75 24. Common Springtail 77 25. The Greenhouse Pillbug, extended 79 26. The Greenhouse Pillbug, contracted 79 27. Dooryard Sowbug 79 28. Amanita Phalloides 86 29. Amanita Verna 87 30. Amanita Solitaria 88 31. Amanita Muscaria 90 32. Diploma, St. Louis Exposition 93 33. Trademark .*'"..; 95 34. Thermometer '-.' 96 35. Hygrometer 96 36. Sprayer 97 37. Mushroom box, ventilated ' 98 Mushroom box, knocked down 99 ©^Cl.A;i50246 I THE CULTIVATED MUSHROOM (Illustrated) PRICE, ONE DOLLAR TABLE OF CONTENTS Page PREFACE 5 PART I— PRACTICAL CONSIDERATIONS The Cultivated Mushroom 7 Essential Conditions ; 8 Temperature 9 Moisture 11 Ventilation 14 Preparation of the Compost 16 Installation of the Beds , 21 Spawning 26 Casing the Beds 28 Watering 30 Picking and Preparing for Market 31 Market Conditions 37 Old Beds .-.38 Open-air Culture 39 Mushroom Spawn 41 Mushroom Enemies 45 Construction of Mushroom Houses 47 How to Cook Mushrooms 50 How to Preserve Mushrooms 53 The Canning of Mushrooms 55 PART II--TECHNICAL STUDIES. The Compost 59 Ferments 70 Injurious Insects 73 Stains 81 Amanita 86 PART III— SPAWN AND SUPPLIES. Pure Culture Spawn 92 Thermometers '. . . 96 Hygrometers 96 Sprayers 97 Mushroom boxes (cartons) 98 INDEX 101 PREFACE Up to a comparatively recent period the various methods of raising mushrooms were based on "bHnd customs." Groping in the dark, guided only by custom, and probably by many failures, mushroom growers would, each for himself, evolve some method of raising mushrooms. The natural laws governing the bacterial and chemical reactions in the compost, mycelial growth, ])arasi- Lic molds, etc., were little understood. Methods were based on observations of effect without definite relation to cause, and, in some cases, even on superstitious traditions. The old text books dealing with the subject merely reflect the obsolete ideas of mush- room growers then prevailing; they contain little information on the underlying principles of mushroom culture, and therefore offer no suggestions of improvement in cultural methods. These books are reprinted from time to time, without change, and, with a new date, are again placed on the market. Meanwhile, science has invaded the domain of mushroom cul- ture and, within the last few years, has made wonderful progress. The secrets of nature have to a large extent been exposed, and the way has been paved for rational improvement in cultural methods and for the intelligent control of essential conditions. The ele- ment of uncertainty has been greatly reduced, and unifomi re- sults are now possible. The object of this book is to collate and present to the public the latest discoveries of science in mushroom culture. Exploded fal- lacies and superstitious ideas are omitted from its pages; modem methods, tested by our most progressive growers, alone are given. Quotations aie from the leading scientists on the various subjects. We arc indebted for much valuable material to the U. vS. De- partment of Agriculture, the staff of the American Spawn Company and the various scientists named in the notes. BURKAU OF MUSHROOM IXDISTRY ACKNOWLEDGMENT We are indebted to the American Spawn Company and their several publications for many illustrations con- tained in this book. All mushrooms shown in the half- tones following this page were raised from "Lambert's Pure Culture Spawn." We make this statement in view of the fact that some of these illustrations have been copied and used without authority by persons advertising other grades of spawn. B. M. I. PART I PRACTICAL CONSIDERATIONS THE CULTIVATED MUSHROOM While nature produces countless varieties of fungi, a comparatively small numbei are well known, and but one or two species are cultivated. The edible variety universally known to epicures is Agaricus or Pratella campestris, so called because of its habit of growing in meadows and pastures. It is to this fleshy species that the commercial term ' 'mushroom " generally has reference . The mushroom has been cultivated for many centuries in all parts of the civilized world; and, in its fresh state or in canned fomi, it has become a very important article of diet. In the United States it may be said that the mushroom industry is still in its infancN-fe although millions of pounds of canned mushrooms are annually imported. However, within the last few years, a steady and ever increasing demand for fresh mushrooms at good prices has induced many people of moderate means to devote some of their spare time in producing mushrooms for the market. Extracts from the reports of Dr. B. M. Dugg.^r, of the Department of Agriculture: THE CULTIVATED MUSHROOM In the United States the term "mushroom" refers commercially to but a single species (Agaricus campestris) of the fleshy fungi, a plant common throughout most of the temperate regions of the world, and one everywhere recognized as edible. From the time of PUny, and perhaps much earlier, this plant has been sought as an article of diet, and it has been cultivated for many centuries. In the vicinity of Paris it has certainly been cultivated in some quantity since the sixteenth century; and, in paintings of market-scenes by old masters of the seventeenth century, a basket of mushrooms frequently finds a place in the composition, thus showing that at that time the sale of mushrooms was generally recognized in a commercial way PRACTICAL CONSIDERATIONS The cultivated mushroom belongs to a class of Crytogams; it is a member of the gill-fungus group, which is itself a subdivision of the group of basidium fungi. The mushroom assimilates oxygen and throws off carbonic acid gas ; it differs in that respect from other plants. This important distinction plays an important part in cultural methods, and should be carefully noted. (See article on "Ventilation.") ESSENTIAL CONDITIONS Contrary to a prevailing opinion, there is nothing mysterious in the cultivation of the mushroom. Any one with a fair under- standing of its cultural requirements can grow this plant success- fully. As stated in a previous publication, mushrooms inay be grown anywhere, at any time and by any one where the following conditions fairly obtain: 1. Good fresh spawn. 2. A properly prepared bed with reasonable protection against weather extremes. 8. A temperature not greatly exceeding 60° F., nor much lower than 50° F. The fully expanded plant, or mature mushroom (sporophore), of Agaricus campestris is well known to every one. It consists of a centrally placed stock or stipe of from 2 to 6 inches in height, usually not more than one inch in diameter, and on the end of this stipe there is borne an umbrella-shaped or cap-shaped portion known as the cap or pileus. The diamej^r and thickness of this pileus vary in different races or varieties of the cultivated form, and also with the conditions of the environment under which it is produced. The gen- eral color of the plant varies in the different varieties from an almost pure white, or cream, to the forms which are deep brown, at least with reference to the upper surface of the cap. The stem is usually cream or white, and bears on its upper extremity near the cap a ring known as the annulus, which an- nulus forms a covering and a protecting layer for the delicate under-surface of the cap, to the edges of which it was attached previous to the rapid ex- pansion and maturity of the latter. The under surface of the cap is provided with leaf-like or gill-like projections, reaching for the most part from the stem to the periphery of the cap. These are termed gills, or "lamellae." They are constantly pink in color in the white or cream-colored species up to the time of (and sometimes even a day after) the separation of the ring from the cap. Subsequently, these gills turn brown and even a deep brownish black. In the brown variety the gills are at first grayish brown but they also become almost black with age. GENERAL CONSIDERATIONS In the United States, fresh mushrooms have only recently been of any im- portance commercially, although florists and gardeners of English and French training have long been successful growers on a small scale. Nevertheless, during the past decade or so, the record of failures has been most conspicuous, and it is certain that, of the many who attempted this work, only a few, relatively, were uniformly successful. TEMPERATURE 9 4. A fairly moist atmo.s]jhcre, avoidin^^ llie frequent and di- rect ajiplication of water to the beds. 5. A gradual renewal of the air, avoiding draughts. In the following ])ages we will review these essential conditions and explain their relation to the growth and development of the mushroom. TEMPERATURE One of the all-im])orlanl and controlling elements in mushroom culture is that of temperature — both the temperature of the at- mosphere in the musliroom house and the temperature of the beds at spa\vning. In this article the temperature of the atmosphere alone will be considered, the other subject being treated under its appropriate head. The temperature of the mushroom house should be high enough to favor the growth of the spawn and sporophores, and yet be low enough to prevent the rapid develop- ment of their bacterial, insect and parasitic enemies. Experience has shown that the extreme range of temperature for profitable The conditions under which mushrooms may be successfully grown are Hmited, and intelhgent attention is therefore essentiaL It must be said, moreover, that the majority of failures may be directly traced to erroneous ideas as to the cultural requisites, or to a reckless disregard of conditions. The essential conditions will be subsequently defined in detail, but it may be stated here that failures are usually due to one or more of the following causes: (1) Poor spawn; (2) very poor manure; (.3) unfavorable temperature; and (4) heavy watering during the early stages of growth. Under suitable conditions mushrooms may be grown with assurance of success. Ordinarily they are grown only where the conditions may be con- trolled, and success should therefore be invariable. TEMPERATURE AND MOISTURE Mushrooms may be grown in any place where the conditions of temperature and moisture are favorable. A shed, cellar, cave, or vacant space in a green- house may be utilized to advantage for this purpose. The most essential factor, perhaps, is that of temperature. The proper temperature ranges from 53° to 60° F., with the best from 55° to 58° F. It is unsafe to attempt to grow mushrooms on a commercial basis, according to our present knowledge of the subject, at a temperature much less than 50° or greater than G3° F. Any severe changes of temperature retard growth, or else act injuriously, and many changes of temperature would entirely destroy the profits of the mushroom crop. From this it is evident that in many places mushrooms may not be grown as a summer crop. With artificial heat they may be grow^n almost anywhere during the winter. Moreover, it is very prob- able that in this country open-air culture must be limited to a few sections, and restricted, commercially at least, to a single season. It is very probable that the exact temperature which may be considered an optimum will vary somewhat in different sections of the country. It will be noted later in detail that the temperature factor acts not so directly upon the growth of the spawn or the production of mushrooms, as indirectly, to render some other conditions of the environment injurious. It is best to consider that in practice the optimum temperature for mushroom growing varies from 53° to 58° F. 10 PRACTICAL* CONSIDERATIONS growing is from 53° to 63° F., with the optimum at from 55° to 58° F. At the latter temperature the enemies of the mushroom are rather dormant or sluggish and will do correspondingly less damage. At lower temperatures the growth of the mushrooms will be arrested, but no harm will result. When the temperature rises again, and the necessary moisture is restored, a vigorous growth may be expected. At the higher temperatures irrepar- able damage will be inflicted, and a poor and unsalable crop will be the result. It is therefore essential that the temperature be constantly and closely watched. For maximum results, it would seem that a measure of control over the temperature is necessary. The dispositions to be made in that respect vary in different cli- mates. It is a comparatively easy task to raise the temperature of the mushroom house to 55° or 58° when the outside temperature is below that mark. The judicious disposition of a few hot- water pipes will acomplish that result. This makes it possible to raise mushrooms in nearly all climates during the fall, winter and early spring. In the summer time, however, in climates where the atmosphere is usually above 60°, the problem becomes more complex, and involves artificial refrigeration. Those growers, however, who are fortunate enough to have at their disposal caves, cool cellars, abandoned mines or tunnels, where the tem- perature uniformly ranges below 60°, can grow mushrooms the year around, and especially in the summer months when the re- duced supply has raised the market price. The question of mois- ture is also more easily solved in the summer, for the reasons outlined under the subject of "Moisture." It was soon definitely ascertained that the conditions of pure culture growth are essentially different from those attending the growth of mushroom spawn in the bed. This was perhaps best indicated by comparing spawn grown in pots at 85° F. under impure conditions with similiar spawn grown at 50° F. At the former temperature, even though the conditions of moisture were properly maintained, there was little or no growth. Foreign fungi, molds, and bacteria, as well as insects, were, however, abundant. At the lower temperature there was little or no evident appearance of other fungi, molds or insects; yet the mushroom spawn grows slowly and continuously so long as other conditions are maintained. From numerous experiments of this nature, it is apparent that the temperature relation is one which is govern- ed by the competition to which the mushroom spawn is subject in the bed. This is, of course, wholly in accord with the results obtained from the study of the relative growth made by mushroom spawn in fresh and composted man- ure. The statement previously mide, therefore, that the optimum temperature may vary slightly in different localities is true on account of the fact that the mites, insects, and other animal pests of mushroom growing may vary consider- ably in different localities, or under different conditions, even though there Ti:MPii;RATURi<: 05 o 12 PRACTICAL CONSIDERATIONS MOISTURE The mushroom, Hke most other fresh vegetables, contains a large proportion of water. It is therefore necessary ■ that water in some form be supplied to it at the various stages of its growth. The bed, when properly prepared, contains enough moisture to supply the mycelium to the bearing period unless it has been robbed of its natural moisture by some of the agencies which we will consider. It must be remembered that the ambient air constituting the atmosphere, normally contains a certain amount of water vapor increasing with its temperature. When the air at a given tem- perature contains all the moisture which it can hold, it is said to be saturated. Beyond that point, the air will not absorb any more moisture, and the excess over the saturation point will be released in the shape of a mist or rain. As has been stated, the capacity of the atmospheric air for moisture increases greatly with its temperature. It follows from that rule, that air satur- ated with moisture at 80 or 90 degrees F. will release, by conden- sation, a portion of this moisture as soon as the temperature is lowered. Conversely, air saturated with moisture at 30 or 40 degrees will, as soon as its temperature is raised, become hungry for moisture and take it from anything within its reach. This explains why the cold atmospheric air of the winter, with a normal moisture content for that temperature, as soon as it is introduced in a warm house, absorbs the moisture from the furniture and even from the throats of human beings living therein. Hence the necessity of supplying additional moisture to this warmed air, for the comfort of the inmates of the house. Again, it is ob- served in the summer that when the warm air strikes a colder surface, like a water pipe, a cave or a cold cellar, the saturation may not be a great variation, perhaps, in the bacterial and fungus flora of the compost upon which the mushrooms are grown. Certain insects, for example, are more abundant in a moist climate, but if special precautions can be taken to eliminate all such pests, the growth problem is confined to the interrela- tion existing between the mushroom spawn and the microscopic flora of the compost. Mushrooms grown in the open will probably show greater varia- tion with reference to the temperature factor than those grown in caves or cellars. The direct effect of a temperature above the optimum upon the sporophores is manifest through the lengthening of the stipes and rapid expansion of the caps, ordinarily accompanied by toughness and decreased size. In other words, the lower-grade market product is produced at the higher temperature. The moisture factor is also one of importance. It is undesirable that the place in which mushrooms are grown should be very damp, or dripping MOISTURE 13 point is lowered and the excess of moisture is condensed on the cooler surface, causing dripping. Applying these principles to the mushroom house, it is cleaily seen that the inside atmosphere must be kept near the saturation point in order to prevent the air from robbing the beds and growing mushrooms of their moisture. This is an easy matter in the sum- nier, because the temperature of the outside air generally exceeds GO degrees F., and when brought into contact with the cooler air of the mushroom house, the saturation point is quickly reached and easily preserved, and there is no loss of humidity. In the winter, however, conditions are reversed. The outside air is colder and has therefore a lower moisture content. When in- troduced into the warmer mushroom house, the saturation point is raised and the newly introduced air proceeds immediately to borrow moisture from the beds. The problem is therefore to supply this air with enough moistiire to bring it near the satur- ation point and thus keep it from robbing the beds of their normal water content. This is done by different growers in various ways. The walls and alleys of the mushroom house may be liberally sprinkled. Some allow steam to escape in the mushroom house and thus provide it with the necessary heat and moisttire at the same time. This process is, however, hard on boilers unless rain water is used. The beds are sprinkled as a last resort, with a fine spray, and then preferably after a picking. It must be re- membered that while the mushroom requires a great deal of mois- ture, it is very sensitive to the direct application of water, and frequent sprinklings are liable to injure it. The mushroom breathes, so to say, and the too frequent application of water closes its pores and interferes with the breathing process. A proper supply of moisture is considered one of the essential requisites of successful growing. The disregard of these rules is responsible for poor yields and many failures. A reliable hygrometer should at all times be hanging in the mushroom house, and the percentage of humidity should never be allowed to drop with water. Nevertheless, a fairly moist condition of the atmosphere should be maintained throughout the growing and productive period. There should be a gradual, but slight, evaporation from the surface of the beds, and sufhcient ventilation to insure this is believed to be essential. It is certain that in poorly ventilated caves mushrooms do not succeed. On the other hand, in a dry atmosphere, or exposed to drying winds, mushroom beds soon cease to bear, while such sporophores as are developing may have their caps cracked or torn. 14 PRACTICAL CONSIDERATIONS below 70, for when the bed has once been robbed of its natural moisture it is well nigh impossible to properly restore it. Since a gradual renewal of the air in the mushroom house is necessary the moisture problem is ever present. VENTILATION Plants, generally, abstract carbonic acid gas (carbon dioxide) from the air and decompose the gas, fixing the carbon that it contains and setting the oxygen free. Mushrooms, on the con- trary, seem to breathe like animals ; they absorb and assimilate the oxygen of the air, throwing off the carbonic acid. This funda- mental distinction should be well borne in mind, as it explains physiological phenomena which are often baffling to the mush- room grower. The quantity of oxygen consimied, and the cor- responding amount of carbonic acid thrown off by the mushroom are enormous. A single mushroom has been shown to exhale 59 milligrams of carbonic acid in the short period of one and one- half hours. It is therefore observed in inushroom houses, where no provision has been made for a gradual renewal of the air, that the growth of the mushrooms is checked or sometimes arrested from the very start; they are said to "damp off", although this condition may also be induced by excessive watering or poorly prepared com- post. Hence the importance of proper ventilation in the mush- room house. The object of ventilation is to remove the carbonic acid thrown off by the mushrooms and incidentally to supply the oxygen so necessary to their development. Carbonic acid gas is about one and one-half times as heavy as air, and is found at the bottom of the mushroom house, in depressions, etc. The exhaust pipes of the ventilation system must therefore extend nearly to the grotmd where they can gather the carbonic acid and expel it from the house just as water is pumped from the hold of a ship. The gas so removed will, of course, be automatically replaced by fresh air containing a new supply of oxygen. Based on the above principles, the ventilating systems may vary according to the location and construction of the mushroom house. Where the floor of the house and the beds are above grade, it is possible to allow the carbonic acid gas to run off by gravity. But where the floor of the house is below grade, the heavier gas must be raised by suction or exhaust and discharged into the out- side atmosphere. This applies especially to mines, caves, tunnels and cellars. VENTILATION r 15 Specimen of EDIBLE MiSIIROOM /'JRIET/ES (iroicn from ''LJM BERTS PURE CULTURE SPAWN'' ^' Cream 16 PRACTICAL CONSIDERATIONS Ventilation by suction or exhaust is effected by various methods. In all cases a shaft or flue is essential. The lower air strata are made to ascend therein by means of a suitable apparatus utilizing the wind velocity, or by the direct action of an exhaust fan. Some growers as- sist the draught in the chimney by building occasionally a fire at its base. Various devices designed to raise the column of air in the flues may be found on the market. The accompanying sketch will illustrate the principle in- volved, and the device may be easily constructed by any tinsmith. The number and size of these devices, re- quired for any particular building, depends, of course, upon it's size, con- struction and location. It is evident ■however, that in large underground .mushroom plants, the positive action of an exhaust fan driven by power is almost a necessity. While a gradual renewal of the air, through ventilation, is es- sential to the healthy development of the mushroom, direct draughts on the beds should be avoided. Draughts will rob the beds and atmosphere of the mushroom house of much needed moisture, affect the growth of the mushrooms and cause the caps to check and crack and to assume a darker color. As will be explained in another chapter, ventilation is not with- out its influence on the temperature and moisture of the mushroom house. A thorough understanding of this relation and of the prin- ciples underlying it will often allow the intelligent grower to make use of his ventilating system in controlling or regulating essential conditions. He may, for instance, take advantage of cool nights to reduce the excessively high temperature in his mushroom house and close the ventilators when the outside temperature exceeds the optimum. V Zn 1 lLATOR_ PREPARATION OF THE COMPOST The cultivated mushroom is best grown on cured or composted horse manure. No practical substitute has been fotmd for this PREPARATION OF THE COMPOST 17 material. It is the best, and also the cheapest. Mueh depends, however, on the selection of the manure. Tlie best manure is })rocurcd from stables where healthy, j^'rain-fed atid hard-working horses arc kept. The manure should contain a fair i)roportion of straw, well trampled, and saturated with urine; the latter is an essential element which is often lost in well-(h-ained barns. The material should be fresh; not over a week old. Manure from bams where horses are kept for pleasure only is not so desirable because the animals do not receive so much j^ain, and the straw and droppings are removed before they are thorough- ly impregnated with urine. Cow manure is unsuitable for the cul- tivation of mushrooms. Veterinary hospitals and bams where chemicals and disinfectants are freely used in the manure .should be avoided. Manure which has been heaped against an outside wall and has been washed or leached in a rainslomi hv the water from the roof, is of inferior quality. As soon as the manure is assembled, it should be well mixed and the dry jmrts should be sprinkled. It is then made up into a pile 3 or 4 feet in height. While the length and width of the PREPARATION OF THE COMPOST It is not to be understood that there is one and only one method of preparing compost for mushroom growing. Nor is it always necessary that the compost shall be in one particular stage of fermentation or decay. In fact, every change of condition elsewhere may necessitate a similar change in the amount of fermentation which may be most desirable. At the outset it should be un- derstood that it is not the "fermentation" that is absolutely essential. The "fermentation" is, of itself, a minor matter. The rapid oxidation action of bacteria, and perhaps of independent ferments, upon manure causes a considerable rise of temperature. At the higher tem- peratures (which may be maintained as long as there are present rapidly oxidizable food products) bacterial action is vigorous, and is unquestionably injurious to mycelial development. Wholly aside from the rise of temperature accompanying their activities, bacteria are otherwise injurious. In fact, manure which is put to test in a small test tube shows little or no rise of tem- perature above that of the place in w^hich it is incubated. Nevertheless, the mycelium of the mushroom will not grow under such conditions. Rapid bac- terial action is therefore prejudicial. Under those conditions where bacter- ial action is not rapid, fresh manure might be used to advantage; in other words, if the beds are so constructed that the manure ferments very gradually, without either excessive bacterial action or rise of temperature, then spawning might be made in fresh manure. The old belief that rotten manure does not have the necessary strength — that is, does not produce so vigorous a mushroom growth as that which has been less transformed by bacterial action — has been confirmed by practical experiments. This loss of effectiveness is probably due, in part, to a change in texture or to other physical changes. In well-rotted manure there is ample food material to support a very good growth of mycelium in pure cultures. This has been chemically proved by sterilizing such manure and growing mushroom spawn upon it in pure culture. Nevertheless, beds prepared with well-fermented manure and left for some time before spawning do not yield so well. It is beUeved that here the physical condition has much to do with the result. 18 PRACTICAL Considerations piles are conventional, depending on circumstances and conven- ience of subsequent operations, the height is uniform and not less than three nor more than four feet. When too shallow, the pile will not heat enough; when too deep, it will heat too rapidly and dry out, and the progress of the fermentation will be arrested. When thus made up, the manure is left to ferment and heat for about a week. The pile is then broken up, the manure is again shaken, thoroughly mixed, and sprinkled if too dry. In the new pile the outside is placed inside and the inside is placed outside, so as to give every part of the whole mass an equal chance to participate in the fermentation. Under average conditions, three weeks and three successive turnings are required to complete the chemical and bacterial re- actions in the manure and effect its transfomiation into compost suitable for the beds. These turnings arc made at intervals of about one week, in the manner described for the first turning. During these operations the material has undergone a radical change, both in texture and in appearance. The characteristic odor of manure is now entirely absent, and has given way to a rather sweet odor suggestive of the mushroom. The material has assumed a uniformly brownish color, velvety to the touch. It should be sufficiently moist to retain its shape when squeezed in the hand without allowing any liquid to ooze from it. Atten- tion is invited to the technical studies on compost and ferments in Part 2 of this book. The latter does not by any means invalidate the following practice, which has commended itself to some very successful growers. The manure is piled in very large compost heaps, where it is kept moist and is turned only once or twice. It ferments very slowly. Then it is carted into the cave or mushroom house, long before it could be considered in proper condition to be spawned. The beds (usually flat when this is the procedure) are made immediately. These are fairly well moistened and compressed, then left to undergo a general fermentation, which may require a month. When the manure shows a ten- dency to fall to the temperature of the room it is spawned. Meanwhile, it will doubtless be found that a heavy crop of some small species 'of Coprinus will have appeared. The presence of this fungus is not injurious, but rather it may be taken as an indication that the conditions are favorable. drdinarily the manure is obtained as fresh as possible. It should include the straw used in bedding the animals, and the quantity of the straw will determine to some extent the value of the manure. The straw of cereals is far better than that of most of the grasses. The more resistant straws seem greatly to im- prove the texture of the compost for mushroom purposes. Commercially it is a mistake to attempt to get the manure free from straw. If fresh manure is not obtainable, that which has been trampled by the animals is ordinarily rich, well preserved, and desirable. It ferments best in large piles, and these may be of considerable extent, about 3 or 4 feet deep throughout. If not uni- formly moist, the material should be sprinkled. At no time is a very heavy watering desirable. In from four days to a week or more the compost should PREPARATION OF THE COMPOST 19 Si?? 20 PRACTICAL CONSIDERATIONS Some growers, at the last turning, mix about one-fifth of loam with the manure. Such addition may have some advantages where suitable loam is found in abimdance and where beds are made in tiers. It makes it easier to "beat in" a solid layer on the springy boards. . It is known that many insects and fungal diseases may be in- troduced into the mushroom house with the compost by the care- less grower. It is advisable to scatter quick-lime over the ground where the manure is to be cured. This will dry out the soil and destroy eggs, larvae and foreign spores. When the compost is ready for the beds it is reduced to nearly one-half of its original volume. A Simple Method for Beginners — The principles governing the composting of the manure ^ though familiar to the experienced grower, at first appear complex to the beginner and often dis- courage him at the start. For the benefit of amateurs who desire immediate results with least amount of trouble, we suggest the following method: Mix in a barn or shed, where material will not freeze during the manipulation, G bushels fresh horse manure (free from long straws), with 2 bushels of good garden loam. Manure should be fresh, not dried, and loam should be moist. If material is fresh, no addition of water is necessary. Leave a few days, provided there is no danger of frost, which would freeze the ma- terial into cakes. be turned, or forked over, and a second turning will be required a week or ten days later. Water should be added only when necessary to maintain a moist (but not wet) condition. With this amount of moisture, and with the piles deep enough to become fairly compact as a result of their own weight, there will be little danger of any injurious fermentation. During the normal fermentation the temperature may rise higher than 150° F. In from fifteen to twenty- one days or more, depending upon the conditions, temperature will begin to fall, and the compost may be used in the construction of the beds. When used in the beds, it has ordinarily lost all objectionable odor, and the color of the straw has changed from yellow to brown. It has been the experience of some of the most successful growers that the use of shavings for bedding material in the stables does not injure the value of the product for mushroom work. The presence of a large amount of sawdust, is, however, objectionable so far as the writer's experience goes. Compost containing much sawdust is necessarily very "short," and therefore the physi- cal condition is not the most favorable for Agaricus campestris. In another chapter attention is called to the fact that the value of the manure depends to a considerable extent upon the feed given the animals. It would not be wise to depend upon that obtained from stables in which hay and green foods are used to too great an extent. Moreover, it is not believed that compost made from the manure of cattle barns in mushroom growing is as desirable as stable manure. INSTALLATION OF THE BEDS 21. Build a small box or i)arlilion in your collar one yard square, twelve inches hi^^h. Brin^' in the material and spread one bushel at a time evenly in the box; tamp it fimily with a brick. Then l)rin<; in the next bushel, and so on. Ascertain the tem]jcrature of the bed at frequent intervals, us- ing a mushroom thennometer. When temperature of the bed has fallen to 7.")° F., plant the spawn, breaking the brick into - killed by strong antisejjtics, it will be reali/x'd that these remedies must be used before the compost or the si)awn are present A. FLAT BED IN A BARN Two t>-pes of beds are in general use, the flat bed and the ridge bed, as shown in the illustrations. Both have their advantages, and disadvantages. If the additional item of labor is not too great, the ridge bed is probably the best. The cone-shaped ridge has a width of IS to 22 inches at the base and an equal height. The smaller ridge is used in wann houses and the larger in cold houses. The ridge bed is more easily INST.\LLATION OF BEDS Mushroom beds are of two general types, (1) the flat bed, frequently re- ferred to as the Enghsh, and (2) the ridge bed, known as the French tj'pe. In making the former the entire floor space may be utilized as a bed, and the beds may be arranged in the form of tiers or shelves, as shown in the figure. In low cellars or caves, and, indeed, wherever the amount of floor space is not the most important cori.sideration, it would be well to avoid the use of shelves; but where the amount of floor space is an important factor they may be adopted to advantage, although the additional labor involved in the grow- ing of a crop under such conditions is an item to be considered. When the shelves are used one should be careful to whitewash these after each crop, in order to avoid the increased danger from insect depredations. In any case, flat beds should be made from eight to ten inches deep. Ridge beds enable one to get a somewhat greater surface space in a given area, but they are also more expensive, so far as the labor of construction is 24 PRACTICAL CONSIDERATIONS ventilated ; it allows the carbonic acid gas, which is heavier than air, to dpain off from its surface into the walkway, being replaced by fresh air containing a normal supply of oxygen. The dimen- sions above given should not be materially departed from. The ridges should be well packed and carefully combed. A path- way of about 15 inches is left between the ridges. SHELF BEDS IN CELLAR concerned. Nevertheless, under many circumstances they are obviously de- sirable. They should be about 2 feet wide at the base, tapering gradually to the apex, and not more than about 18 to 20 inches high when compressed and cased. The custom is to make two such beds in contact and then to leave a walk-way of 8 or 10 inches between the next two, and so on till the space is occupied. Next to the walls slanted beds may be prepared. In any case, the manure is made up in the form of the bed desired, and should be firmed or compressed in order to prevent drying out and burning when the second fermentation takes place. At this time the manure should be neither wet nor dry, but merely moist. The only practical test of the proper mois- ture content of the manure which can be relied upon is when upon compres- sion water cannot be readily squeezed out of it. The prevalent opinion among amateurs that the bed should always be deep enough to maintain considerable heat is believed to be erroneous. Grown under more or less uniform conditions, mushrooms seem to require no bottom heat, and the bed should fall to the temperature of the room some time after spawning. Bottom heat, and hence large beds, are, however, desirable when sudden changes of weather would so reduce the temperature of the bed as to delay growth. Under similiar conditions, as well as in the dry air, mulch- ing may be required. INSTALLATION OF THE BEDS 25 » «;: ■Wife'* « « . # '■;t>V -***»' -''^^\v ^^^ ' ^t> ^'- «■■ • -.««»»^ 26 PRACTICAL CONSIDERATIONS The flat bed is probably more generally used in the United States because it is more easily constructed and involves less labor. Flat beds are made about ten inches deep. There is no advantage in making them deeper, and the foregoing remarks, about the larger ridge bed may well be applied to the deeper flat bed. Mush- room beds do not require bottom heat. In caves and tunnels, flat beds are ordinarily built on the ground. The floor may be of dirt, cement or boards, and should previously be disinfected with quick-lime. Provision should also be made against seepage. In cellars or mushroom houses, beds are often built in tiers ; the same precautions should be taken to insure clean- liness. To prevent the accumulation of carbonic acid gas on the flat beds, they should, if possible, be slightly inclined towards the al- leyway in the center, so as to allow this gas to drain off as fast as it is exhaled by the mushrooms and be replaced by a new supply of oxygen. In making the beds, either flat or ridge beds, the compost should again be mixed and divided so as to be of unifonn composition. It is then well packed and tamped, preparatory to spawning. The critical stage of the operations has now arrived. The temperature of the beds may rise very materially, and again the rise may be insignificant. A reliable thermometer is now an absolute neces- sity, as the beds must be constantly watched until spawning. SPAWNING The best temperature of the beds for spawning has been found by repeated experiments to be about 70° F. It is dangerous to spawn at a higher temperature, and a proper start may not be secured if spawned at a lower temperature. Spawning should never be attempted when the temperature of the bed rises, as it is likely to rise beyond the danger point and kill the spawn. This SPAWNING AND CASING THE BEDS From what has been said concerning the temperature requirements it will be evident that spawn should not be inserted in the beds until the temperature has fallen low enough to insure successful competition on the part of the my- celium with other organisms. In many articles on mushroom growing it has been suggested that beds may be spawned when the temperature has fallen to about 90° F. From e.xperience and observation, the writer can only conclude that such a temperature is frequently fatal, and it is believed that the temperature of the beds should be permitted to fall to 70° F. be- fore being spawned. In fact the most successful results have been obtained at temperatures from 65° to 70° F. It was formerly believed that if the spawn were inserted at 90° F. this higher temperature incited the rather SPAWNING 27 is the fatal mistake which is often made by beginners who have otherwise carefully observed cultural directions and who are at a loss to account for their failure. The thermometer in the beds should be constantly watched, and as soon as the temperature of the beds has dropped to 70° the spawn should be planted immediately. If this opportunity is lost.-a poor crop is sure to result. This emphasizes the necessity of having the spawn on hand before the critical time. It should therefore be ordered at the early stages of the operations, so as to make liberal allow- ance for delays in transit and for other unforeseen contingencies, it is safest to order the sjjawn before the preparation of the com- ]jost is undertaken. Under i^ropcr conditions of storage, brick spawn will keep for sc\'eral months without deteriorating, and it can be shii)pcd by freight, in quantities of fifty bricks or over, at lower rates. Special emphasis is laid on the foregoing consider- ations because there is a tendency on the part of the grower to deku' ordering his spawn until he is nearly ready to use it, under the mistaken impression that it will be fresher when he receives it. The brick of spawn is broken in about eight pieces, which will spawn about eight square feet of beds. The practice of sawing the spawn is to be discouraged, as it tears and destroys a consider- able portion of the mycelium. Brick spawn alone is considered in this article, as it is not practi- cable for the average mushroom grower to handle or use loose spawn on account of its very perishable nature. It has been found advisable to dispose the spawn about to be planted on the bed a few days be- fore time of spawning has arri\^ed. The natural moisture of the bed will thus cause the mycelium of the spawn to gradually swell, and thus more readily run in the beds when planted. The spawn thus treated could not, however, be dried again for future use without material injury. Under no circumstances .should the si)awn be dij^j^ed in water before planting; such treatment is al- most sure to result in ])emianent injury. This warning would seem superfluous to the experienced grower, except for the fact that we have actually seen the practice recommended in some publi- cations. dormant mycelium to rapid and vigorous growth. It is clear, however, that the rapid development of the new mycelium from the pieces of spawn brick inserted is not so important a factor as suitable conditions for continued growth. If the temperature falls rapidly from 90° F. after spawning, however, no injury will result. Nevertheless, it is to be considered an un- fortunate condition. 28 PRACTICAL CONSIDERATIONS When the beds are in proper condition, they are spawned by inserting a piece of spawn about one inch below the surface. The hole is then filled, and tamped so as to insure intimate contact between the spawn and the compost. Care should now be taken that the beds do not lose any of their moisture. The walls and alleyways should be sprinkled to keep the atmosphere moist. The direct application of water on the beds at this stage is ex- ceedingly dangerous ; it is most likely to cause the delicate fibrous mycelium to rot and die. The beds should, however, contain a nonnal amount of moisture if the compost, has been properly cured. The mycelium of the spawn, whose life has been suspended, will now soon show signs of activity, and in a few days will radiate from the piece of spawn and slowly permeate the compost. Cas- ing of the beds should not be undertaken until the growth of the spawn has taken a fair start and extends a few inches into the bed. About a week after planting a small quantity of material near the spawn may be removed in the hand and examined in a strong light. If the spawn is running, a grayish fuzz will be observed in the material, and, if sufficiently extended, the time for casing has ar- lived. This occurs ordinarily from one to two weeks after spawn- ing. Casing should not, however, be delayed too long. CASING THE BEDS Casing consists in applying to the bed a layer of loam from 1 to 13^ inches deep. It is essential that this loam be free from lig- neous or putrefying matter which might introduce into the bed injurious molds. The loam should be neither clay nor pure sand. Calcareous loam, or calcareous sand mixed with some good loam, The bricks of spawn may be broken into from 10 to 12 pieces, from 13-^ to 2 inches square. These pieces may be inserted about 1 inch beneath the surface of the manure. In flat beds they may be placed from 10 to 12 inches apart throughout the bed, and in ridge beds should be inserted on each side alternately, one near the top and the next near the bottom. It is well to in- sert the pieces vertically, as the mycelium does not then seem so readily to suffer damping off. After spawning the beds should again be firmed, and they are then ready to be cased or loamed, whenever this process may seem most desirable. At the time of spawning the beds should be in the best con- dition possible for the growth of the mycelium. Delay in growth at this time is one of the surest indications of a light yield. If the bed contains the proper amount of moisture, and if the walls and floors of the house or cellar are sprin- kled occasionally, so as to maintain a moist condition of the atmosphere, it is possible to avoid wholly the use of water upon the beds immediately after spawning. In no case should a bed recently spawned be heavily watered. CASING THE BEDS 29 is the best. The loam used for the casinj^ should be fairly moist, and that condition should be preserved by keeping the atmosphere of the mushroom house saturated with moisture, or by a very light spraying on the casing. A casing which is in a muddy con- dition, or which is too dry, may be injurious to the growing mush- rooms. The casing should not be applied until the spawn has been observed to nm, but should not be delayed much thereafter. Under nomial conditions this will occur from 1 to 2 weeks after spawning; this is under normal conditions. When clay loam is a])plied to the beds in a muddy condition, it will completely shut off the air from the beds and will at the same time to some extent check the escape of the carbon dioxide which is continually generated in the interior of the beds. Moreover, such a mudd}' surface will later on dry and fonn cracks on the sur- face of the beds, thus breaking the mycelial threads, if any, that may have reached the surface to fonn small mushrooms, and damp- ing off is almost sure to follow. If, before the casing is applied, the beds show moldy areas as if a plaster had been sprinkled in patches, it is evident that such beds are affected by the plaster mold (MoniHa fimicola). Such patches should be sprinkled with powdered quick-lime when the surface is wet, or sprinkled with a one or two per cent solution of water and lysol if the surface is dry. This treatment is recommended when the infection is on the surface only where it has been brought from without. If the mold is found also in the interior of the bed (the result of poorly- composted manure) there is scarcely any remedy for it, and a maximum yield cannot be anticipated. The surface may be sprinkled, if there is a tendency toward drying out . The same test for moisture content as has been outhned previously in these pages in the chapter on preparing the manure should be followed. The beds should become, gradually, somewhat drier, however, during the growth of the spawn. The absolute water content for the bed at the time of spawning should be about 40 per cent, although this will vary considerably, according to the con- ditions, and especially with relation to the quantity of straw in the manure. If the spawn grows rapidly at first and spreads throughout the bed, it will not be injured by a slight drying out, or by a temperature even as low as 32° F. On the other hand, a continuous high temperature for several days, or excessive watering, is sure to result in irreparable injury. In several in- stances where the experimental beds of the writer have been made during the late autumn and where a vigorous growth of spawn has been secured before the advent of the coldest weather, the beds have remained unproductive throughout the winter months, or so long as the temperature remained in- termittently below 40° or 50° F. With the warmer weather, these beds have come into bearing several months later, and where the temperature has then remained favorable for some time a good yield has been obtained. In this case, moreover, the bed will bear much longer at a temperature of G0° 30 PRACTICAL* CONSIDERATIONS Several theories have been advanced to explain the function of the casing in the production of the mushroom. One thing is certain: without casing, little or no crop would be obtained. It is claimed that following a biological law peculiar to cryptogams, when the mycelium meets a changed medium which is no longer nutritious for it, it will become at once transformed into cylindrical stems and, upon contact with the air, will expand and fonn the button which later becomes the mushroom. Under this theory, the function of casing would be purely physical and the addition of fertilizers to the casing would seem to be superfluous. As a matter of fact no absolute time can be laid down, for the appearance of the mushrooms is not only dependent upon the uniform temperature in the mushroom house, but also upon the quality of the compost, the care used in its preparation, the quality and condition of the spawn, the degree of moisture of the beds, and even the composition of the casing. Beds have been known to lay dormant for a number of months, and again have commenced to bear within six weeks after spawning. As long as there is spawn in the beds which is properly rvinning and is not being re-absorbed, a crop may be looked for. If there is much delay in the appearance of mushrooms, the cause should be investigated and remedied. If the spawn has been killed by a material rise in the temperature of the beds after spawning, or by other causes, there is, of course, no remedy. WATERING Mushrooms, like other plants, require water; yet surface water- ing on the mushroom beds causes more or less injury. The mushroom requires oxygen to live; a sprinkling of water falling on a pin head mushroom completely covers it and consequently F. or above, than if the temperature has been constantly in the neighborhood of 60° F. throughout the growing season of the spawn. As a rule, beds thus filled with spawn and then subjected for a time to cold conditions yield at the outset much larger mushrooms than beds exposed to a more constant temperature, even if this constant temperature may be optimum. At any rate, the beds must be "cased" as soon as convenient after the spawn is inserted. As a rule, one should wait from one to two weeks in order to be sure that the spawn is growing.' Casing consists in applying to the bed a layer of loam from 1 to IJ^ inches deep. In France the casing soil consists of cal- careous earth, sometimes mixed with loam. Ordinary loam of almost any quality will suffice. This should be secured in advance, and it is well to pro- tect it from the weather, so that at a convenient time it may be worked over, and if necessary screened, in order to free it from large pebbles or trash. When the loam is applied, it should, on ridge beds, be carefully firmed. When cased, a bed should require watering for the most part merely to maintain a moist surface. PICKING AND PREPARING FOR MARKET 31 shuts off the air necessary to its existence. It practically drowns the mushroom, so to say. Likemsc, on the beds, a film of water will seal them, especially when clay loam is used, and thus prevent the escape of the noxious gases generated in the interior of the beds as well as by the mushrooms and growing sj^awn. Water vapor used in saturating the atmosphere is the best means of supplying the needed moisture without causing any injury. The walls and alley^vays of the mushroom house can be liberally sprinkled, but the sprinkling can should be used on the beds only as a last resort. PICKING AND PREPARING FOR MARKET The experienced mushroom grower can readily ascertain, by surface indications, when the mushrooms are about to appear on the beds. White, fuzzy patches, more or less regular or cirailar in form, may be seen around the places where the spawn has been planted. The casing will bulge and crack here and there, showing white globules. These growths may appear in the shape of white filaments, or may be composed of white vesicles running together. These manifestations should not, however, be confused with the efflorescent growth known as Monilia fimicola, the common "plaster mold," resembling in appearance an accumulation of white grantilations suggesting plaster spots. Hence the popular name of the disease. WATERING As previously indicated, the spreading spawn should receive no water, or at least as Httle as possible. When, however, the mushrooms begin to appear, more water will be required, and a light sprinkling may be given once or twice each week, or as often as the conditions demand. Beds which come into bear- ing in proper condition should never be drenched. It has been found by ex- perience that under the most favorable conditions a bed will require occasional sprinkling, since, owing to continual evaporation, there will be a gradual loss of water, at least after the mushrooms begin to appear. Sprinkling should be made after the mushrooms have been gathered, and the loam disturbed by the removal of the mushrooms should always receive a light sprinkling. PICKING AND PREPARING FOR MARKET When a bed is in full bearing the mushrooms should be gathered at least once in two days, and it is well to pick them every day, particularly if the tem- perature is up to 60° F. or more. Picking is itself an art, and the intelli- gent owner will soon find that the yield of a bed may be greatly lessened by lack of judgment in picking. To satisfy the general demands of our markets at the present time it is not recommended to take the buttons; yet, if there is a fancy trade for these, it should be met. Little or no gain of weight occurs in the mushroom, however, after the veil begins to break, so that mushrooms should not be left after this time. Flat tops are a third-grade article, but these, as well as all defective mushrooms, should be sedulously removed from the bed every day. 32 PRACTICAL CONSIDERATIONS It is often found that some strange fungi appear on the beds in advance of the regular crop, the germs of which may have been introduced in the mushroom house with the compost. Chief among these intruders is the Coprinus, a species of which is here- with illustrated. Another species of the same genus is more squatty in appeal ance. They are short-lived, and the gills soon COPRINUS COMATUS (SHAGGY MANEJ Before and after the gills have been dissolved dissolve, forming a black, inky liquid; they are sometimes called "ink caps." The appearance of these fungi, which are edible, is considered by some a rather favorable omen. The picking of the mushrooms should not be left to unintelli- gent or inexperienced hands. It is an easy matter to lose or waste half of the crop through careless picking. In harvesting the crop one should not be guided by the size of the mushrooms, but rather by their condition and stage of maturity. For example, a mush- room with a small cap and a long stem should not be allowed to In picking, grasp the mushroom by the cap (a large one by both cap and stem) , twisting it to remove it easily from the soil. Where the mushrooms come up in large united clusters, it will be best to cut them, in order not to disturb the mycehal connections of all. Some good growers practice "cutting" through- out, but the stubs must decay and are a source of danger. After all good mushrooms from a cluster have been taken, remove any fleshy spawn masses adhering and add fresh loam. PICKING AND PREPARING FOR MARKET 33 remain until the following day, for it will not