Controlling the growth of mushrooms in conditions of nutrition

Biuletyn Producenta Pieczarek PIECZARKI 4/2015 s. 16-23

Providing mushrooms with resources needed for the expected yield, or the substratum and casing soil and sufficient quantity and weight of the spawn does not automatically mean the possibility of obtaining high yields, even if we have sufficient technical conditions to maintain microclimate conditions required for its growth and development. The wide variation in yields and not achieving their maximum size in relation to available resources is a fact. This means that we still do not really know how to control the behavior of the mushrooms. This is the second problem necessary to solve in order to achieve the intended objective of getting yields of 40 kg/m2 in three flushes. The issue of controlling the nutrition of mushrooms turned out to be much more difficult than expected at the time of acceding to build technology based on it. The current system of microclimate control in the cultivation hall turned out to be not fully useful to obtain stable yields and required development of new rules to ensure control of the behavior of mushrooms (in particular evaporation). Our knowledge about the causes of the variable behavior of the mushrooms during growth is also not full.

Controlling includes three major processes described below.

Recolonization of substratum after sowing feeding supplements. The purpose of controlling is to prevent hyperactive behavior of the substratum and to assimilate the mushrooms with introduced to the substratum feeding supplements. Achieving this goal is the first necessary condition to obtain the planned level of yield. Breakage of spawn in an overgrown substratum interferes achieved during growth balance between it and the thermophilic organisms (Scytalidium). This is due to the fact that – after breakage of the spawn and disengagement of the substratum during removal from the growth tunnel – between the straw there is more oxygen than before disengagement. Once incorporating therein a quantity of water necessary to balance the dose of feeding supplement, and as it has a high temperature, it causes multiplication of these organisms. This results in a rapid increase in heat and even faster proliferation of thermophilic organisms, while inhibiting the activity of mushroom spawn. If this rise is not interrupter before the temperature reaches over 32°C, it is life-threatening for spawn or significantly weakens it. Although the substratum is cooled intensely, by reducing the air temperature and increasing its movement, the balance between spawn and thermophilic organisms cannot be generally restored and to complete the second flush the cultivation is done over large temperature differences between air and substratum. This means that the shock is much more difficult to carry out and it is also hard to control transition to the second flush when the temperature of the substrate is high and tends to rise from the middle of the first flush. The fruiting bodies of the mushrooms are subjected to excessive evaporation of water from them, and thus the yield is reduced.

Please note that adding feeding supplements to the substratum requires an additional amount of water required in the digestion (broken spawn colonizes the substratum once again and digests the feeding supplement with enzymes until the end of the shock) and transportation of nutrients to the fruiting bodies. This requires the development of a program of pouring water into the substratum. This program is modified depending on the season, humidity and behavior of the compost.

Keep in mind that the cultivation of mushrooms on substratum with excessive activity requires a different approach to control its growth.

Transpiration – evaporation of water from the surface of the fruiting bodies, which determines the rate of their growth. The aim is to obtain the maximum weight while keeping the characteristics of fruiting bodies typical of the breed cultivated throughout the harvesting season. Mushroom do not have any slits in its rind, which means that the rate of evaporation of water from its surface (in accordance with the process of transportation of nutrients) depends mainly on the parameters of the microclimate and the temperature of substratum. Both too fast growth of the fruiting bodies and too slow worsen their welfare, its quality and weight. This is due to disturbance of the balance between the collection of water from the casing soil and the substratum, transport of nutrients and growth of the fruiting body weight (number and mass of cells and cell membranes). Transpiration may be too fast or too slow.

  • Too rapid evaporation makes the fruiting bodies lightweight, flat (Fig. 1 and 2), with the husk, prematurely stretched membrane and is often accompanied by shafts that are cracked inside. The result is a loss of weight of fruiting bodies, and thus the yield. Fruiting body with a diameter of about 4 cm (fig. 3 and 4) having the same volume can vary the weight from 40 to 25 g. Assuming a standard of 35 g, this means a large drop in yield, up to 25% with the same amount and the same size of fruiting bodies collected. This decline intensified since mid-flush collection. The appearance of light fruiting bodies, without changing of their shape does not necessarily mean that every time the reason for this is excessive evaporation. This may also be a result of water deficit in the substratum. This also happens when using dry substratum produced during the high summer temperatures. Then the watering will result in a return to the standard weight.
    Loss of water is easy to tell by observing the volume of fruiting bodies in a standard box of 2.5 kg. It can be filled in the middle (heavy fruiting bodies) in the first days of harvest of the first flush, and in following days full when fruiting bodies are lightweight and despite of this fact they have the same weight. Weight of fruiting bodies should be monitored regularly during harvest.
  • Too slow evaporation is causing greasy stains on the fruiting bodies, their growth is slow, skin is pink and yellow and there are dark rings in the stalks from which it is easy to squeeze out the water.

The current evaporation control system is based on measuring the relative humidity but it is imprecise; always indirect. The assumption that the relative humidity reflects the evaporation of water from the surface of the skin (transpiration) does not work in practice. The amount of water that can be introduced into the air, is determined by water deficit. It is not identical with the evaporation of water from the skin surface of the mushrooms. Therefore, a proposal to introduce the term „transpiration” in relation to release of water vapor by mushroom is made as opposed to evaporation of water in the casing soil or floor covering. From the standpoint of cultivation transpiration is essential.

Factors that determine the course of transpiration, are as follows.

  • The deficit of water in the air in the cultivation hall. It is described also as the relative humidity or water content in the air and read from the Mollier chart. The higher it is, the greater the evaporation is.
  • The air temperature. With the increase in air temperature transpiration increases.
  • The movement of air. Transpiration increases with increasing air speed over the fruiting bodies.
  • Atmospheric air pressure. The higher it is, the smaller the evaporation.
  • The amount of fruiting bodies and growth rate of their weight on the shelf; skin surface of all fruiting bodies. The higher it is, the higher the amount of water evaporated. Traditionally, it is advisable to increase or decrease the air changes depending on the number of fruiting bodies on the shelf.
  • The temperature of the substratum. As the temperature is increasing and the difference between the temperature of the air and the substratum is greater, the evaporation of water is greater. Differentiation of activity of substratum during the cultivation in Poland is very significant. This translates into the rate of evaporation of water from the fruiting bodies and the casing soil and the rate of growth of fruiting bodies. The current system does not include this parameter.

The problem complicate even more when we change several parameters at the same time.

Figure 1. Fruiting bodies growing at an excessive transpiration
Figure 1. Fruiting bodies growing at an excessive transpiration
Figure 2. Fruiting bodies growing with proper transpiration
Figure 2. Fruiting bodies growing with proper transpiration


Figure 3. Fruiting bodies before harvest
Figure 3. Fruiting bodies before harvest
Figure 4. On the scale
Figure 4. On the scale

The process of control is based on:

  • maintaining the water content at a certain level (usually it is 12 g, and the range varies from 10 to 14 g),
  • maintaining a constant air movement on such a minimum level at which the air conditioner is running smoothly and there is a movement over all the shelves,
  • air temperature changes during yielding period, mainly being increased to maintain the desired water content in the air (range from 17.5 to 21°C),
  • maintaining the desired relative humidity of the air that is based on the Mollier chart for the particular water content in the air,
  • changes of concentration of carbon dioxide (from 2000 to 7000 ppm) during yielding in order to maintain the required level of water content in the air while minimizing its movement,
  • maintaining the lowest possible air humidification in the tunnel, using watering devices installed under shelves or along the side walls.
  • maintaining percolation of water from the substratum to the casing soil.

Although control of these parameters does not always allow to achieve the desired effect in the behavior of fruiting bodies. This is due to the fact that the amount of evaporation (transpiration) is assessed indirectly.

The current control system of growth of mushrooms is based on the principles of evaporation of water, in our case with the wick of a dry-bulb thermometer. Hence the search for methods to assess the actual evaporation. One such way is to use evaporometer. For this purpose, an attempt was made using 50 g mechanical postal scale (Fig. 5 and 6). This allows to capture the moment when evaporation is blocked, as indicated by no loss of water weight, or the point where evaporation is too fast. The amount of water evaporated will depend not only on the chosen parameter values, but also on the surface of the pan filled with water.

We are currently working on determining the correct size of evaporation, watching both its size and behavior of the pins and fruiting bodies. In addition, observations are used of pace of drying floors and weight loss of fruiting bodies and appearance of the husk. Currently, it is assumed that evaporation should equal 1g over 12 hours from an area of ​​200 cm2. This issue will be returning in the future. The tests used Piches evaporometer.

The location of measurement of the parameters of the air in the cultivation hall is of significance too. At low air movements the difference in the reading of wet and dry thermometers traditionally placed in the hall and  measurement of the same parameters two centimeters above the fruiting bodies, pins or spawn reaches 20°C,  depending of the increased air movement. This means that a significant difference in measuring relative humidity.

The domination of pins. The aim is to obtain the desired density and number of generations of pins in each successive flush. The principle is that all buds are formed during shock and released in each successive flush. They are differentiated, meaning creation of generations, in accordance with the principle of diversified growth of younger and older pins and of stronger and weaker. In other words, they are differentiated by their so-called periodic arrest and release. In the first flush to adjust the density and the amount of generations initially by a shock, and after the formation of a pins differentiating microclimate conditions inhibiting the growth of weaker and smaller pins, keeping the growth of the oldest and largest (Fig. 7). In this article I’m not interested with the issue of controlling the shock, since the outcome is more dependent on experience of the person handling the shock than the process of nutrition. What facilitates replication of its course is the use feeding supplements into the casing soil. In the transitions between the flushes the process of releasing pins is also depends on other factors, of which the most important are listed below.

  • Harvest. Only conducting a selective harvesting and preventing the closure of shelf space by fruiting bodies allows for a gradual release of pins from the middle of the flush practically without interruption or with only a one-day break between harvesting of another one. Closing the shelf will reduce and delay the next flush of the fruiting bodies even up to three days, and significantly reduce the harvest period, notably during the second flush.
  • Microclimate conditions. Raising the temperature in the air and the substratum; renewal of this activity causes the released pins to
Figure 5. Post scale as evaporometer
Figure 5. Post scale as evaporometer
Figure 6. Writing down the changes of water loss
Figure 6. Writing down the changes of water loss

grow simultaneously. After completing a flush it is unadvised to change the microclimate parameters to ensure constant evaporation of water from the surface of the casing soil and its transpiration of pins, supported by a large periodic variation in carbon dioxide from 2000, up to as much as 10,000 ppm, limiting and accelerating air movement.

  • Watering. Direct watering after harvest causes the simultaneous release of the pins. Therefore, it is advisable to make one dose of water when pins are varied, for example one or two days after the completion of harvest.
  • Salinity of the casing soil. At high content it permanently reduces bonding in each flush. But this kind of salinity of casing soil is not found in Poland. It has to be induced artificially and is used primarily in the cultivation of portobello mushrooms.

It is important in the process of mushrooms nutrition to maintain a constant gas exchange between the substratum, the casing soil and the air in the cultivation hall and maintenance of percolation of water from the substrate to the casing soil. Constant evaporation of water from the casing soil significantly stabilizes the microclimate in the cultivation hall.

Knowledge of the process of nutrition and controlling it is the foundation of effective course of growth and developing one’s own technology.

Figure 7. Improper transition between the first and second flush
Figure 7. Improper transition between the first and second flush



In the next three issues of the Bulletin I would like to describe the problem of growing mushrooms based on controlled process of its nutrition in a series of three articles. This article describes the process of nutrition. In the next; the second of this series, the process of controlling the behavior of mushrooms will be described, and the third will be on raw materials, tillage and technologies used in mushrooms cultivation. Understanding the fundamental processes of life of mushrooms, especially its nutrition and ways of controlling it allows for efficient use and development of the proposed new technology.

Why current technology based on Dutch experience does not have development potential in Poland?

The classical approach states that the substrate is the basis for obtaining high yields of mushrooms. This means that it should be of a high abundance of nutrients necessary for its yield and stable quality. The requirement of stable quality is not being met in Poland in relation to the Phase III substrate. Let me remind you that the country produces a substrate based on straw and chicken manure under high diversity of quality of raw materials and in highly variable climatic conditions during the year. In this situation, an integral part of the production of Phase III compost is incorporating protein supplements. They provide the expected high abundance of nutrients and stable quality. What the concept of stabilization of the compost by the use of protein supplements is based on? Con Hermans explains it in the article Compost (2) „Good compost needs good nutrients” published in Mushroom Business number 23 (April 2015 p. 4 to 6). Rich compost can be considered as one which has a specific content of nitrogen. In case where it is too low, protein supplements are used to obtain a stability of its contents. They enrich it with nitrogen. As a consequence of using a protein supplement on the substrate with poor content of nitrogen the yield could be increased up to 8 kg\m2. With substrate with the average content of nitrogen the increase is up to 3 kg\m2. In case of nitrogen-rich substrate it is unprofitable. In the article there is no information, at which level the amount of supplement these effects can be achieved. There are no indications in Hermans’ article of ways to practically determine the dose of supplement to obtain desirable effects and not to suffer losses when it is introduced unnecessarily. What further complicates the use of protein supplements has to assess the quality of the substrate through the C\N ratio. While this ratio is important at the initiation of composting and during evaluation of Phase I and II substrate it is significant, the situation with Phase III substrate is quite different. The phase III substrate is a mixture of Mushroom spawn and undecomposed compost. It means that, by determining the level of nitrogen in the Phase III substrate one is specifying its contents in the spawn and substrate but there is no way of knowing how the nitrogen is distributed among them. This makes it quite difficult to ascertain doses of the supplement. It is worth noticing that using maximum dose of a protein supplement for compost rich in nitrogen can lead to a reduction in yield.

In practice, the maximum size of a protein supplement dose does not exceed 1.25% of weight of the substrate. The basic dose is 1.0%. The limitation of the dose is due to the inability to control the temperature of the substrate after application of the casing soil when the doses are higher and in particular, when the compost is not fully colonized by the mushrooms spawn. As a rule, one does not differentiate between doses of protein supplement because of the characteristics of compost, unless upon request of the recipient.

To summarize the use of protein supplements does not allow for the elimination of variable richness in nutrients and stable quality of compost. Fluctuations in the yield of the phase III substrate are still considerable and reach up to 10 kg\m2. Besides, average annual yield higher than 32 kg\m2 cannot yet be achieved.

As a starting point for creating new technologies of growing mushrooms assumption is made that its yield depends on the mass of the spawn in the first and second flush, and in the third and the rest flushes depends on the activity of thermophilic organisms in the compost; Scytalidium thermophilum coexisting with Mushroom after spawn’s growth (cold composting phase). During the period of mushroom’s yield the activity of enzymes is much less important.

To live, grow and reproduce mushrooms need:

  1. Water. It has several functions: it is a component of the cell sap, transports nutrients, and controls temperature. Active water is of particular importance, but its role in the diet has not been fully elucidated.
  2. Nutrients. They are collected in the form of aqueous solutions:
    • energy substances – a source of energy and carbon in the form of polysaccharides, taken as glucose or fat decomposed by lipase, and absorbed mainly in the form of fatty acids (e.g. butyric acid), and glycerol. The issue of mushrooms’ demand for energy is not important in this article. Observations conducted during feeding tests show that incomplete meeting of the demand for energy in spawn during its enzymatic activity restricts the use of the substrate in the first two flushes. The constituents of cell membranes of straw are a major source of carbon and energy for mushrooms. It is composed of lignin, cellulose and hemicellulose. These components are available for mushrooms, because Mushroom is equipped with the enzymes that are taking part in their decomposition. These enzymes are referred to as Carbohydrate Active enzyme system (CAZyme). Lignin is primarily degraded during the vegetative growth of the spawn until placing of the casing soil with the participation of manganese peroxidase and laccase. By contrast, cellulose and hemicellulose are degraded after application of the casing soil by the cellulose. In mushrooms nutrition starch is mainly used as an intermediate element of decomposition of polysaccharides to glucose.
    • Nitrogen in a mineral form – mainly in the form of ammonium ions to create amino acids, and in organic form to create endogenous amino acids from proteins; components of the cell sap and chitin responsible for supporting structure of fruiting bodies.
    • other minerals, especially phosphorus, sulfur, potassium, magnesium, sodium, calcium, manganese. The role of calcium is of particular importance as it is regulating the pH of the substrate and casing soil and it has important effect on binding of fruiting bodies. Most micronutrients affect the process of feeding by enzymes in which they occur. One’s attention should be drawn to the special role of manganese.
    • regulating substances (vitamins – especially biotin and aneurin, and growth substances).

The starting point in determining the nutritional needs of the mushrooms may be its composition. On average, it is assumed that the mushroom has 94 – 97% water, 2-4.3% protein and other organic compounds, including 0.2-0.7% of carbohydrate and 0, 05-1, 1% of mineral salts (mainly phosphorus, magnesium, potassium, calcium, iron) and microelements, vitamins and biologically active substances. Taking the highest indicated content of components in mushrooms, this means that with a yield of 40 kg/m2, it absorbs from a substrate and a casing soil: 36kg of water; the amount of nitrogen and amino acids needed to produce 1.7 kg of protein; glucose and other sugars to produce 2 kg of carbohydrates and to maintain vital functions; unsaturated fatty acids to produce 0.28 kg of fat; mineral salts – 0.44 kg.

The general diagram of nutrition is as follows:

Polysaccharides + enzymes of Mushroom →glucose (C6H1206) →respiration (O2) = 6CO2 + 6H2O + energy                                                              ↓

                                                                 + NH4+ = chitin (spawn and fruiting bodies)

In compost the source of dead cell walls are straw subjected to hot composting process (fiberisation and other) and cell walls of dead thermophilic organisms (mainly actinomycetes) multiplied in the process of maturation.

The mass of spawn depends on the activity of enzymes of mushrooms and the availability of dead organic matter created in Phase II compost. The highest activity of the enzymes takes place at a temperature of 250C. The concept of nutrition as a source of additional nutrients (feeding supplements) uses crafted caryopses of cereal and not protein supplements. The caryopses also contain protein. They – crafted caryopses of cereal introduced into the Phase III compost – are to: stabilize the quality as well as providing additional nutrients than those found in the substrate and also through the casing soil to achieve a specified level of yielding. Why cereals? Cereals are grasses and mushrooms in the wild grow in meadows (Mushroom campestris) and evolutionarily adapted to use the resulting humus formed on them in the composting process; mineralization which the dead grass undergoes. In addition, the caryopses of cereals contain all the ingredients necessary for diet of mushrooms.

The average composition of cereal seeds and soy is as follows::

Cereal seeds          Soy

  1. Assimilative carbohydrates    60 -70%       3,4 – 4,5%
  2. Cellulose                              1 -4%          3,5 – 4,5%
  3. Proteins                                          9-14%         45 – 48%
  4. Fats 5 -4.5%         2,0 – 3,5%
  5. Minerals                        1,0 – 2,0%.       5,0 – 6,0%

The rest is water. Summary shows the basic differences in the carbohydrate content in favor of cereal seeds. These seeds also contain enough proteins, fats and minerals for the nutritional needs of mushrooms. These proportions are most similar to the composition of the Mushroom. It has needed enzymes to degrade components of the caryopsis of cereals, mainly carbohydrates of varying chain lengths consisting of glucose. The shorter the carbohydrate chains the easier the process of decomposition into glucose. Decomposition of cellulose is the hardest. This explains why we do not grow Mushroom on straw as is the case with Pleurotus.

Mushrooms are in much smaller quantities provided with enzymes degrading proteins or fats. Mushroom has considerable abilities to adapt the available enzymes to nutrients in the compost. This explains the usefulness of supplements made from cereal grains to feed the mushrooms by casing soil. In addition, the main source of nitrogen for the mushrooms is nitrogen in the form of NH4+, located in the substrate as a result of ammonification of proteins in the composting process.

The period of the biggest enzymatic activity of mushrooms’ spawn in the process of feeding starts after bringing the supplement to the substrate or the casing soil to the end of spawn’s growth after shock in conditions of access to water in these two environments. During this period, temperature of 250C and a high concentration of carbon dioxide and water access are expected in the compost and the casing soil.

Decomposition of compost by thermophilic organisms continues from the period of yielding of the first flush. It is their enzymes that decompose the compost; the mineralizing it provides Mushroom with additional components. It is illustrated on the diagram provided below:

Organic matter + O2 + aerobic microorganisms Þ


CO2 + NH4 + PO4 + biomass of microorganisms + thermal energy + humus

(After: Mieczysław BŁASZCZYK i Magdalena FIT, Sukcesja mikroorganizmów w czasie kompostowania odpadów organicznych [Succession of microorganism during composting of organic waste])

In case of mushrooms decomposed organic matter in the substrate is the one that was not decomposed by Mushroom and microorganisms are Scytalidium thermophilum. This process explains, among other, why the availability of water in the substrate increases during the third and subsequent flushes. This diagram explains also the way the protein supplements work, the increase in temperature and the increase in nitrogen content in the compost. This mechanism is also a cause of hyperactivity of compost; production of large amounts of heat, which makes it difficult to control the behavior of fruiting bodies; and the process of releasing pins in the second and subsequent flushes.

By mastering this process outside of compost, it would be possible in getting the supplement that would allow nourishing the mushrooms in the third flush.

An important novelty of the proposed approach for growing mushrooms is to expand the location where the feeding takes place on to the casing soil. Until now it was thought that it should be deprived of nutrients, as this can interfere with the binding process. Conducted research showed that the mushrooms using their enzymes decompose peat. It was the starting point for the introduction supplements from cereal grains into the casing soil. Initially it was thought that one will need to create double layered casing soil; separate for the nourishment and another one for binding. This proved to be unnecessary. The efficiency of nutrition process is due to two facts: first, there are no microorganisms in the casing soil, so they do not compete and do not consume, even partially, introduced nutrients, and second they are in the near distance from the pins and fruiting bodies. Why is this so important? Because the nutrients contained in the spawn must be transported to pins and fruiting bodies and incorporated into the forming cells and keeps them alive. They must also be accompanied by the transport of water. These two processes are undervalued in the cultivation of mushrooms. They explain many of today’s problems as causes of lower yields in the second flush, loss of quality from the middle of the first flush and also explain the high efficiency of feeding by a casing soil. Nutrients are transported through the mechanism of osmosis between living cells. Transport is relatively slow because it is about 2 cm per day. In contrast, soluble nutrients are transported in the process of water evaporation from the surface of the skin. They move in dead cells that make up a kind of „pipes”. This is practically the same mechanism as in plants. Please note that skin of mushrooms does not have stomata (defending itself against excessive evaporation by creating scales). This means that the transport of water depends on the water content in the air. When too much water evaporates, the deficit is too high which causes the fruiting body to become light and lose its shape. When it is too low or the evaporation is blocked, the fruiting bodies soaks up water excessively, the first sign is a ridge on the shaft, the mushrooms lose color, the fruiting bodies become pink or gray and stop growing. The same applies to pins. When this situation is maintained for a long term they burst and die.

Supplied nutrients are utilized in the increase in the number and mass of cells as long as there is a correlation between water transport and access to nutrients. The pace of transport and weight gain depends on the air temperature surrounding the pins, the fruiting bodies and the spawn during shock. This is often much higher than the air temperature measured by the sensors in the hall. This means that the shortage of water (water content) needed for the evaporation is sometimes (with the rapid growth of fruiting bodies, their high weight and increasing activity of the substrate) significantly different and considerably change over time. In case of disruption of evaporation mushrooms stop growing and fruiting bodies begin to prepare for the production of spores; they form a film under his hat and opens; entire supply of nutrients is used to produce and seeding spores. Mushroom receives a signal that its living conditions are bad and must therefore quickly produce spores, that seeding is its primary life goal. However, if conditions are good it tries to grow to maximum size, because it gives a chance to produce the greatest number of them.

Mushrooms in the subsequent flushes have to transport nutrients from the spawn that is increasingly distant from the surface of the casing soil. Transport is relatively slow. The acceleration by an increase in evaporation leads to a reduction in yield; fruiting bodies stop growing and open. It is therefore important to maintain the conditions providing transport and on the other hand, introducing supplement to casing soil to shorten the transport route. At first glance mushrooms have enough nutrients accumulated in the spawn located close to the fruiting bodies and those located in the casing soil can be used to increase the yield of a second flush. Nevertheless excessively rapid growth of fruiting bodies from the middle of the first flush may lead to a deficit of nutrients. This increase of evaporation is caused by excessive activity of the substrate.

As a side effect of the growth of mushrooms, heat, carbon dioxide and steam are emitted. In the controlled process one must take into account the need to remove them outside the cultivation hall. Otherwise, they distort the course of the expected behavior of mushrooms.

New ideas, technologies and the development of Polish mushroom industry

Nikodem Sakson

Business development is based on one hand on overcoming the existing barriers, and on the other hand on searching for new ideas and technologies, which would allow achieving better results at its everyday functioning. Polish mushroom industry is nowadays a significant part of this business all around the world.

Four unsolved problems of mushroom industry all over the world

  1. Stagnation and variability of mushroom yielding resulting from lack of improvement of quality and stability of produced compost. In Europe for years now the average yield of mushroom on fresh market using the phase III compost has been reaching a level of 30–32 kg/m2. Whereas on the world 40% usage of substratum can’t be exceeded, regardless of the raw materials used and technologies of producing the substratum.
  2. Pests and diseases, mainly dry rot and green mold still cause significant loss of crops.
  3. For years there hasn’t been a satisfactory improvement in reducing the cost of work during the manual picking.
  4. Malodorous odors, which occur during a production of phase I compost, are still a problem in development of mushroom industry.

The production of substratum became nowadays a significant part of poultry production, transferring a part of profit to poultry industry. This means that mushroom industry is participating in maintaining competitive prices of poultry. In this situation poultry industry doesn’t bear the costs of utilization of excrements emerging during the production of broilers and eggs. This at the same time means that production of mushrooms is more and more becoming an element of environmental protection. How to assess such role of mushroom industry? Especially, that composting plants largely take part in utilization of other wastes from other animal productions, not only poultry. The reason for this is that some of supplements of phase III compost have animal waste. Clients buying mushrooms bear the costs of this utilization.

New ideas solving current problems of mushroom industry

  1. The growth and stabilization of mushroom yielding and the level of substratum usage.

Problem: If the production plants are equipped accordingly, why isn’t it possible to achieve regular yield of 20 kg/m2 in the first and second flush? Periodically the yield achieved in the first flush sometimes reaches the level of 23 kg/m2. The same can be said about the yield from the third flush, as it doesn’t exceed the level of 5 kg/m2, and the abundance of compost allows reaching the same level in the fourth flush.

Still not less than 60% of compost mass has to be utilized, even though mushrooms should be able to go on yielding.

Solution: A new paradigm: „growing mushrooms is a controlled process of its nutrition”.

It is based on four assumptions. First two relate to nutrition:

1. Mushrooms take part in a process of mineralization of galenical dead matter. Mushrooms’ nutritional needs are based on acquisition of energy, carbon, water, oxygen and minerals from it. Dead organic matter with adequate composition provides all the nutritional needs of mushrooms. Achieving the yielding of a certain level it is necessary to provide an access to needed amount of nutrients, balanced by the need of water and with access to oxygen.

2. The yield of first and second flush is dependent on the mass of the spawn, where the nutrients and water are accumulated. The growth of spawn’s mass can be controlled by the process of recolonization, when transfer of nutrients and water from the substratum to spawn takes place. The spawn of mushrooms in a casing soil shouldn’t dry out nor should casing soil have deficit of water during the whole yielding process. Yielding in third and later flushes depends on the course of the process of cold composting of the substratum on a shelf without its active participation.

The other two assumptions relate to controlling the way pins and fruiting bodies behave:

1. To achieve an expected level of yield by supplying the nutritional needs of mushrooms it is necessary to use the effect of domination of pins and growing fruiting bodies by creating and controlling the behavior of its individual generations.

2. The process of nutrition has to be carried out in conditions of controlled growth of the mass of fruiting bodies, which at the same time provides water and nutrition uptake by them. This means maintaining the welfare.

  1. Cultivation of mushrooms without using pesticides.

Problem: Is using pesticides necessary to protect cultivation of mushrooms from diseases and pests?

Solution: It isn’t necessary because mechanism of biosuppression of mushrooms can be used in relations to competitive mushrooms, located in a substratum. During the process of biosuppression mushrooms eliminate microflora unfavorable for her. They achieve this goal by increasing concentration of carbon dioxide, by changing the PH of the environment and by producing hydrogen peroxide during enzymatic digestion of nutrients (compost and supplement). In case of green mold (there are no infections at the moment) the problem may possibly be solved by intensive recolonization connected with increasing the amount of water during this period.

The same mechanism can be used in case of germinating spores of fungal diseases, which attack the spawn during the period of yielding (dry and white rot). Those fungal diseases are residue of primal infections, which means the residue of spores of those diseases in a casing soil after placing on the substratum. This process can be supported by adding salt to casing soil with large dosage of water, which washes the casing soil. Effectiveness of biosuppression is additionally enhanced by very short period of time from putting the casing soil to shock (4 days), with balanced dosage of water and added supplement.

A special diet can be used in the nutrition of mushrooms, which elements would also deter diptera.

Rapid growth of spawn’s mass during the recolonization period can secure substratum from colonization from nematodes.

  1. Production of substratum without malodorous odors.

Problem: How can odors are eliminated during production of compost?

Solution: They can be eliminated by omitting phase I during the production of compost. It is yet an unsolved question whether on such substratum the same or bigger level of yield can be achieved in comparison to cultivating mushrooms on traditional compost.

American research using cut corn stover in production of substratum omitting phase I is a beginning of work on solving this problem. Theoretically it can be assumed that it is possible. The process of nutrition of mushrooms allows this. But more research on wider scale is needed.

  1. Improving effectiveness of selective harvesting.

Problem: Can selective harvesting be simplified such way that its efficiency is enhanced, yield and the quality of collected fruiting bodies is improved?

Solution: It can be achieved by introducing a device choosing fruiting bodies to collect automatically (Advanced Mushroom Research). It could choose only those fruiting bodies, which should be collected. Harvesting too early (loss of mass) or too late (loss of quality) could be avoided. Such way additional lowering of costs could be possible, by hiring cheaper, less trained workers. Possibility of controlling effect of domination and incubation of fruiting bodies without loss of quality should improve results of using this device.

Other ideas

Other ideas existing in the industry can be pointed out:

1. Balanced production of mushrooms by taking ecological actions, especially conserving energy used in production. Mushroom Business propagates it the most.

2. New strains of mushrooms which give improved level of yield and better quality.

3. Nutrigain develops other concept of growing based on nutrition of mushrooms on every stage of its production, by using their own products from natural nutrients.


Using grinded and crafted corn as a supplement for substratum and controlling nutrition of mushrooms.

Using controlled nutrition based on a supplement containing grinded and crafted corn is a technology of production of mushrooms that should be done in following stages:

  1. Replacing protein supplements with supplement from crafted corn on a level of 0, 5–1%.

This change allows reducing the cost of supplement and stabilization of the yielding if small decreases of quality of substratum occur. The possibility of increase of quality of fruiting bodies also occurs, only if the amount of corn and mushrooms’ need for water in compost is balanced. This technology allows improving the quality of fruiting bodies and stabilization of yield on a level of 30 kg/m2.

  1. Stabilization of production on average yearly level of 32–34 kg/m2 and 2% dose of corn as supplement.

There is a possibility to improve yielding level to 37 kg/m2, with a dose of supplement up to 2% and putting casing soil in amount of 85–90 kg/m2. It allows improving the usage of fresh substratum mass up to 43–44%. In this case the necessary condition of achieving mentioned effects is also balancing the amount of water with the dose of used supplement in the recolonization phase and applying procedures of control of the behavior of pins and fruiting bodies during the whole period of incubation. Yield of this level is probably the limit of this supplement’s ability of improvement. Further additions to compost most likely do not balance the needs of mushrooms, so it could improve yielding based on nutrients contained in minimal amounts in compost. Problems with nutrients like for example microelements could be the reason for this.

  1. The 40+ technology of nutrition – average yield on a level of 40 kg/m2 of mushrooms with over 95% of best class, with reduction of production costs by changing the diet further. Continuation of research of technology allowing such results is needed.

In a longer term a new standard of quality of Polish mushrooms should arise. It should be promoted on main markets, improving competitiveness of Polish producers.

Technological gap

One can say that a technological gap occurred in Poland this year. It is connected to mushroom production on phase III substratum that is available on a market. This gap is a result of development of technology in Poland. Right now from technical point of view the gap reaches 5 kg/m2 and it will increase possibly up to 10 kg/m2 next year. This gap is even bigger from economic perspective, because such results can be achieved by reducing the need of energy by around 10% and reducing the cost of pesticides by 2 zł/m2. It is also achieved by increasing the level of the yield by 5% and 5-10% increase in income as a result of improving the quality of collected fruiting bodies and prolonging the time of their usefulness for sale. Gaining such results doesn’t require additional investments and is accompanied by reducing the fixed costs.

This technological gap can be intensified after development of new technology of production of substratum with omitting phase I, which was up until now necessary in production of compost. It could reduce the cost of producing substratum even to 50%, but some other additional investments will then be needed. Scale of this investment is difficult to estimate, because of lack of specific technology. At the moment it can’t be indicated when or where such technology will appear, and what will be the level of yield of mushrooms.

Implementation of new technologies

The basic question is: who will be implementing new technologies in a situation when companies which create their own efficient new technologies and bear the costs of adapting them, will master the production of mushrooms and will get desirable effects, are not interested in sharing it. It is in their interest for technologies to be popularized slowly, because it provides them with longer period of innovative profits. Those profits can reach 20% of production costs without additional costs of acquiring and adapting the technology, which are relatively low.

Is it possible nowadays to repeat the situation from years 2000 – 2004? At this time thanks to the transfer of technology from Holland and adaptation to polish conditions essential improvement of the level of yield was obtained (around 2 kg/m2 bigger than in Holland).

Mushroom industry in Podlaski in consideration of technological gap.

It is mainly in Podlaski Region where the biggest development of Polish mushroom industry takes place. This question can be asked: is it true that in this region 90% of Polish mushrooms are produced, or is it just information created by media? Regardless of these facts, changes in this region will shape the future position of Polish mushroom industry. It is in Podlaskie, where the production of mushrooms is growing the fastest and it is there, where the biggest investments into area of cultivation are located. The biggest producers groups are working in a best way at this region. The location of Podlaskie is very favorable considering the market and this region has the greatest access to cheap labor, this is why it is the most competitive in relations to other countries of EU. However the amount of compost production is insufficient, what requires supply from other regions of Poland. But the amount of production of casing soil is larger than the local demand. Additional advantage of Podlaskie is employed people, they are diligent and resistant to difficulties, and they also have advanced skills in trading with the East.

In situation when new technologies are introduced the basic questions are: how will conservative local community manage the necessity of creating and using new technologies of production and will typical for peripheral regions trends of staying competitive by using cheap labor and imitating solutions introduced by other producers be preserved? Does it mean that preferable model of development will be the one using investments and innovations that are introduced somewhere else, as it successfully worked in a past? At present there are no actions towards creating new technologies in Podlaskie. Obtained additional financial resources are allocated for other purposes.

Why does functioning in existing now satellite mushroom production system does not allow development?

The reasons of lack of development in satellite mushroom production system, which dominates in Europe at present, are:

  • This system leads a market game with zero results. It doesn’t endeavor revenue growth and reduction of the costs of production by innovation, especially soft innovation. The game applies just too sharing profit between participants of the system (producers of raw materials, producers of mushrooms, suppliers of means of production, sales organizers). At present the improvement of production and keeping the profit level is done by investments increasing the production area. Permanent decrease of profits is a result of the continuing fixed prices of mushrooms and increasing costs of their production. This last phenomenon is counteracted by the industry by conducting promotional campaigns that support the growth of consumption of mushrooms. The goal is to induce growth of demand over supply, at the same time inducing growth of prices, for produced mushrooms. The effect of this situation is that interest in other actions concentrated on development is reduced.
  • Producers functioning in the satellite mushroom production system do not take independent actions in which the goal would be to create and adapt innovation, gain knowledge and raise their qualifications, because they do not want to bear the costs. So far information and training were given to producers in Europe for free from state or as a part of marketing strategy of producers of raw material. In mushroom industry information is not treated as a commodity, and sharing is considered a social mission. When state stopped being the source of information, and is not responsible for qualification of farmers, producers of mushrooms are having problems with navigating themselves on a market of information, ideas and technology. At the same time the creators of those information, ideas and technology treat them as a commodity. Besides, if new, effective technologies and innovations will be popularized slowly, the innovative profit for their creators will last longer and will be bigger.
  • The most of suppliers of raw materials are presently not interested in popularization of new technologies and innovations too. The reason for this is that they are afraid that new technologies and innovations could destroy the balance of the forces on the market. Transfer of information and counseling given by companies supplying raw material are a part of marketing and this determines the scope of their free offer.

Following question is essential: will the change of generations (that is undergoing right now) favor innovation of the mushroom industry in this field or will it favor growth and preserving the current model of production?

The location and people are not without significance. Poland, despite the size of its production and the position of the biggest exporter of fresh mushrooms in the world, is seen as a peripheral country that can only adapt innovations and not create them. It is the Dutch who are still considered the ones to create innovations and share them around the world.

Creating necessary technological innovations, especially in the field of automation of controlling the cultivation or using robots in production is the other issue here. There is no indication that this type of actions have been taken in Poland.

It is very important to answer the question how will the mushroom industry in Holland (which is the biggest competitor of Poland in production of mushrooms on fresh market) be developing? Will there be at least a partial transfer of production on fresh market from this country to Poland? Will other competitors arise, who will choose to use the same development mechanism and even cheaper labor?

Forecast of development

It can generally be assumed that present direction of change will be maintained. That means investments into bigger areas of cultivation. This situation could be maintained by introducing in more and more EU countries minimum wage on increasingly higher level. Presently and in the near future Polish minimum wage will stay on a level of 25% of minimum wage of countries which are the biggest consumers and producers of mushrooms in EU. As a result the market can still grow at the cost of local producers in the countries mushrooms are exported to. That means that Polish producers will reach the limit of demand, when 70% of production of mushrooms on fresh market will come from Poland.

Changing regulations about odors, crop failure of straw, arising of competitive market or invasion of pests or diseases can be considered the most important threats for the smooth functioning of the industry. Russian market collapse could only mean a temporary downturn.

Development by new technologies will accelerate during the time of crisis. However one shouldn’t expect it in times of prosperity.

Industrial production as a development factor

Industrial production can become essential factor of development of production of mushrooms on a fresh market. Following characteristics should determine this:

In my opinion popularization of innovation and new technologies can be much faster in companies that lead industrial production of mushrooms

The rules of industrial production

  1. Mini/max. Minimal dependence on nature and maximal control of the technological process
  2. Full cycle of production – from raw material to individual sales (including marketing).
  3. Effect of the scale
  4. Internal sources of development of technology, as building strategy of development.
  5. Management and organization focused on development.


The technological gap is a fact and it has opportunities to increase, not decrease. Because there are difficulties in creating and adapting soft innovations in satellite mushroom production system and there is no market pressure on reducing the costs of production, it is to be expected that implementation of new technologies will be on smaller scale and only in companies interested in moving towards industrial production of mushrooms. The main participants of the market in the satellite mushroom production system, in Poland and Holland as well, are not interested in changing the principles of functioning and leading in this system. The low costs of labor will encourage preservation of the present model of development.

Substrate and nutrition

At present technology of growing mushroom without phase I composting, developed by A.M. Slater, is considered the most promising solution. The purpose of this change is to eliminate the malodorous emissions from compost production. The basic raw material used in this production without malodorous emissions is cut corn stover. It is subjected to a process of pasteurization and incubation, and obtained as result compost undergoes the process of spawning and millet – produced strains of Scytalidium thermophilum are introduced. The main change of this technology in comparison to classical method of producing compost is renouncement of phase I, which helps with full elimination of the sources of malodorous emissions, mainly chicken manure. The rest of cultivation is not changed. Which means, that the main assumption – that growing of mushroom is a controlled process of its usage of substrate – stays unchanged? The question whether such prepared environment of nutrition of mushroom could be called a substrate remains open. From my point of view this solution could eliminate the problem of malodorous emissions, but doesn’t solve the problem of stagnation and changing yielding of mushroom on compost. It yet doesn’t answer the question of the ways of controlling compost’s abundance in nutrition available for mushroom. Cut corn stover is a structural part, being a carrier for spawn and, at the same time, serves as nutrition. The same is with straw compost and chicken manure. This means that the process of nutrition cannot still be controlled.

I myself think that other solution of a problem of substrate for mushroom (also with malodorous emissions reduction) is possible, under a new proposed paradigm – growing Mushroom is a controlled process of its nutrition. For this purpose a model of such substrate was made and is now being tested. First of all the goal is to achieve an answer on how does a nutrition process of Mushroom itself work. Only then, after collecting information about a process and conducting multiple tests on usefulness of different diets, it could be possible to build a new technology of growing under a new paradigm.

Available tests and changes in technology of growing mushroom on compost using crafted corn as a supplement allow indicating the key elements of new technology, which are:

  1. Control of the process of transfer from compost to spawn of mushroom of bigger doses of crafted corn in a process of recolonization. This allows to achieve essential improvement in yielding above those which are obtained from compost. It requires skillful control of balancing of water introduced to compost with increasing doses of crafted corn.
  2. It is confirmed that yield from the first and second flush depends on nutrients and water that are collected in spawn. The process of collecting, that is enzymatic decomposition of substrate (compost and supplement) done by enzymes produced in hyphae and transferred of achieved this way nutrients to ryzomorphic mycelium. This way an average yield in two flushes of 40 kg\m2 of fruiting bodies yearly can be achieved, maintaining the full welfare. Efficiency of third flush is relatively low. 5 kg\m2 of fruiting bodies is a still unbreakable barrier. In this situation collecting fruiting bodies of third flush can be treated as additional effect achieved without additional expenditures or one can just resign from it. In case of resignation from a third flush, the process of cold composting can be omitted.
  3. Mastery of effective control of the process of domination of pins and incubation of fruiting bodies with full maintenance of welfare means that the effects of change in the composition of substrate on achieved yield can be compared to yield achieved on compost with its own supplement (crafted minced corn) oscillating around the level of minimum 35 kg\m2 in two flushes and in then yielding in third and fourth flush on a level of minimum 5 kg\m2.

To get substrate without composting it is necessary to establish the list of assumptions, which it has to realize and a list of unanswered questions related to the process of nutrition. The questions arising from analysis of theoretical knowledge, constructed models and technology. Getting precise answers on established assumptions will not be possible due to lack of possibility to perform laboratory tests and also lack of precise statistical testing. The reason for this situation is that all the research is being made during the process of production and because of its pragmatic character. Undergoing works are an element of growth of a company which has limited resources on founding research and development. The main goal of this research is to answer the question about developing new technologies and not to explain why such effects of introduced changes occur.

Following assumptions were established:

  1. All the components used in the process of production will have to be biodegradable and will have to be a part of the circulation of organic matter in nature.
  2. All the components used will have to be a subject to standards related to food and feed of plant origin.
  3. New technology will not be using pesticides.
  4. The structural part will be separated from the part responsible for nutrition. Structural part will be responsible for keeping spawn’s position after incubation and not to change it after introduction of water to substrate. It is also responsible for gas exchange during the whole process of cultivation. The nutrition part will have to have balanced composition meeting the nutrition needs and planned yielding in the welfare.
  5. The water must be available during the process of transfer, covering the needs of cooling of the substrate and keeping the needed for the process of transfer temperature. The transfer of water and nutrients will be controlled.
  6. The period of transfer will be dependent of the amount of nutrients introduced during the time of recolonization. The bigger the dose of nutrients the longer the period of transfer.
  7. The components of substrate must be free of pathogens and will have to provide worse conditions for competitive mushrooms. They will have not to lure pests of mushroom, mainly diptera.
  8. In case of cultivating in three or more flushes, Scytalidium thermophilium must be introduced.
  9. The production process must not be dangerous to the environment and has to be the shortest as it is possible. The best solution is that the amount of time from the beginning of the process of production of substrate to the beginning of putting the casing soil and the start of recolonization lasts no longer than seven days.
  10. The substrate has to be much cheaper. Especially the usage of non-renewable energy in its preparation must be much lower.
  11. Used up substrate should still be suitable to be used in a production of mushroom or to other purposes. It will be best if it meets the requirement of sustainable production, especially that corn is used as a part of human diet and animal feed.

 Which hypothesis will be verified?

  1. Which nutrients do the mushroom collect form the substrate? Does it behave like an animal or a plant? If like a plant, does it mean that it needs – in relations to assimilation – reversed source of energy, carbon, minerals and oxygen, and the rest – proteins, fats, other nutrients and components regulating incubation and development – produces for itself. Or like an animal, there are some components like amino acids or vitamins that it cannot produce for itself and has to collect them from the substrate.
  2. Does Mushroom need monodiet and compost is the one? Does it, for example, need dead matter of mesophyll microflora, actinomycetes (humus complex)? Or is it an organism with a diversified diet and could feed on for example corn or potato starch, etc.? In other words, what is the range of opportunism of mushroom?
  3. Is crafted corn enough to achieve a planned goal of yield of 40 kg\m2 in two flushes? How much should be used, what groups, and how much water is needed during the process of transfer?
  4. How long will the period of transfer take? What are the signs of its end? How to control spawn’s need of water during the process of enzymatic decomposition and transfer to ryzomorphic mycelium? Would measuring the suction force be helpful in control of introduction of water to substrate?
  5. Is microflora needed in the process of nutrition, if yes what kind? Is it possible to produce a substrate in which the process of biosuppresion and commensalism would not be needed? Are they specific only for compost?
  6. Could spawn placed on a substrate produced without the process of composting (without rotting and pesticides) after the end of production is used as a component of human diet or could be used as animal feed? Every cell of mushroom, no matter where it is located has the same nutritional value. Is it true to spawn in substrate considering increased content of insoluble calcium oxalate?

Growth of Mushroom bisporus on corn stover colonized by thermophyllic fungi (Scytalidium thermophilum and Myrioccum thermophilum) and their influence on substrate selectivity. Amber Marie Slater; Daniel Joseph Royse; Schreyer Honors College, Pennsylvania State University, 2010.

12.2014 Summary

The primary purpose of a new approach to mushroom production is to develop a new mushroom cultivation technology. The implementation of this technology would allow the collection of a regular harvest of an average annual yield in three flushes at a minimum of 40 kg/m2 of high quality mushrooms, with the highest grade content not less that 95% and minimum 7-day marketable shelf life.  This goal should be achieved without any increase in the operating costs. The operating costs such as supplements, common salt, higher water amount, carbohydrates, and calcium chloride are included in the costs planned for protein supplements in an amount of up to 1.5% of the weight of the substrate phase III. This is accompanied by a reduction of production unit costs of one kilogram of mushrooms. It amounts to 10 – 20% and depends on the increase in the yield and reduces the amount of energy used in the production process that contains a microclimate control by changing production parameters.

The end of the test cycles and advancement of mushroom technology based on the new definition (as controlled feeding), allows summarizing the following facts regarding the mushrooms cultivation and making the first assessments regarding the proposed approach. They have been presented in 12 Reports.

Initially, this situation allows answer the question: Is the proposed collection of the most important concepts and statements on which the new technology is based on allows for better explanation (understanding) the production process, better system known facts and allows the development of new cultivation methods? The production practice will be answered if the obtained responses are correct and truthful with the actual situation.

Basic principles concerning the mushroom cultivation based on a controlled feeding application:

  1. The yield of the first and second flush of mushroom production depends on the mass of mycelium in the compost and the casing layer; the content of nutrients and water available during the phase of overgrowing the substrate, and its recolonization after the application of supplements. Recolonization plays an important role in a production cycle because it creates nutrient resources for the mushroom.
  2. Mycelium mass depends on the amount and type of available dead and organic matter that is a source of energy necessary for mushroom yielding (compost, supplement and water) and the process of its decomposition by the CAZy enzymes produced by mushroom mycelium.
  3. The water must be balanced with the applied supplement. The water should ensure the required temperature (without thermal effect) of the substrate during the entire cultivation period, efficient utilization of the supplement during the process of enzymatic digestion, transport of nutrients into the rhizomorphic mycelium and further to fruiting bodies and mushrooms.
  4. Water (free) applied into the compost during recolonization is utilized for the digestion of nutrients present in compost enhanced with the supplement and also transferred to the substrate. This process protects the substrate against decay despite the use of water doses significantly exceeding water capacity of the substrate and the supplement (50-70% of the fresh weight). Water shortage significantly decreases compost moisture when a supplement is provided and in result reduces the yield.
  5. Water availability during the feeding process needs to be controlled by measuring the suction force in a substrate and casing.
  6. Nutrients accumulated during the vegetative mycelium growth are used in the controlled process of initiation and growth of mushrooms to keep their well-being. Either stimulus or linear approach is used to changing the microclimate parameters. The stimulus approach is applied when the domination of the stronger and older fruiting bodies, and mushrooms over weaker and younger needs to be employed. It allows in the increase in number of harvested mushrooms and the control of their size at harvest. In contrast, linear approach, which introduces small but permanent changes in microclimate parameters, allows keeping a water shortage in the cultivation hall and providing the required evaporation of water from mushrooms and casing, essential for growth of fruiting bodies and mushrooms. Linear changes need to be implemented ahead of time to guarantee expected constant growth and increase of mushroom mass. Water evaporation from the mushrooms can not be faster than the transport of nutrients from the mycelium. It also applies to the casing layer because excessive evaporation results in water shortage and thus causes earlier spore production and loses of volume weight. To avoid high looses earlier harvesting is crucial.
  7. Planned changes of carbon dioxide content in a cultivation hall play a key role during the feeding process. Carbon dioxide concentration is very important during the process of growing fruiting bodies to provide an environment, which enhances a required shape of fruiting bodies (bulbous). To maintain an appropriate interval between generations of fruiting bodies it is also necessary to control the dominance of older fruiting and stronger bodies over the younger and weaker. At application of water dosage greater than 1% of a supplement dose, mycelium produces carbon dioxide at such a high level that it can be used for the control of growth of fruiting bodies and mushroom under conditions of balanced water. Increasing carbon dioxide concentration for a short time to very high levels can inhibit the growth of fruiting bodies and mushrooms.
  8. Higher air and substrate temperature is required during yielding. It is supposed to create more favorable conditions for increase of cell mass and cell membranes, and water in the cell. Throughout the harvesting period it is also required to maintain a constant temperature difference between the air and the substrate.
  9. Water shortage in the casing that results in mycelium decay decreases mushroom yielding due to reduction of mushroom mass and number of fruiting bodies in the following flushes. Weaken mycelium during water shortage is more sensitive to the development of dry bubble disease (or brown spot).
  10. Cultivation in the subsequent flushes should be carried out according to a feeding cycle assumption.
  11. Yield of the third flush depends on available nutrient ingredients being dissolved in water during cold composting and also during feeding through casing with utilization of carbohydrates. Quality of nutrient ingredients available during cold composting depends on Scytalidium thermophilum activity and feeding program. These postulations need further verification.

The presented statements are not conclusive yet and along with the development of technology, exploring new scientific facts and testing of developed models will get their final shape, especially with regard to the third flush.

The establishment of new idea and based on its technology and accompanying innovations allow for reflections on the course of hypothesis dissemination in the future. The question that is worth asking is the following: will dissemination spread out according to the theory of “diffusion of innovation” formulated by Rogers during the Internet era  (Diffusion of Innovations, 5th Edition Everett M. Rogers)? Or could this be controlled and deliberately disseminate the information? These questions should be addressed separately in relation to the ideas, technologies, and particular, single innovation. It seems that dissemination of the new idea and a single, simple innovation using the Internet can be efficient and quick. However, dissemination of new technology is much more difficult.  Overall, I think both the individual innovations that are a base for new technology, and the technology alone will be propagated very slowly during the era of satellite production system, which dominates in Europe today. The reasons are following:

–        A system runs a market game with a zero result. It does not aim at an increase in profits and decrease in expenses by implementation of new innovations, particularly soft innovations. The game refers to the distribution of profits between the participants in the system  (producers of materials, mushrooms, provision of the means of production, sales organizations). Currently, an increase in production and maintenance of the profit level occurs through investments escalating production area. Permanent reduction of income is due to the fixed prices of mushrooms at the rising costs of their production. The latter issue is being taken care of by running promotions that would increase mushroom consumption. It is supposed to result in the increasing demand that should be higher than supply and in consequences higher prices. .

–        Producers of mushrooms functioning in the satellite system do not take independent actions such as implementation of innovations, development of knowledge and skills, as they do not want to pay additional costs. So far, in Europe individual country or companies promoting their products provided information and trainings. The information is not in the commodity and dissemination is treated as a social mission. Mushroom producers do not find information, new ideas and technology easily available since when a country ceased to be a creator of information and is not any responsible for qualifications of producers. At the same time the creators treat them as a commodity. In addition, if new, efficient technologies and innovations are slower disseminated, the innovative annuity for producers manufacturers who implemented them, will be higher and obtained for a longer time.

–        Most of the producers of raw supplies are also not interested in the dissemination of new technologies and innovations. This results from a concern that new technologies and innovations might disrupt the current market situation. The transmission of information and counseling provided by the companies that provide supplies are part of marketing, and it determines the range of their free offer.

The place of their origin and the person creating them play a significant role. Poland, despite a large mushroom production and the largest exporter of fresh mushrooms in the world, is recognized as a peripheral country that can only assimilate innovations but cannot create them.  The Dutch are still considered as the only nation that is able to develop and disseminate new technologies.

In my opinion, the dissemination of innovations and new technology can be much faster in companies carrying industrial production of mushrooms.

Principles of industrial production

  1. Mini/max. Minimum dependence on nature and maximum control of technology.
  2. The full production cycle – from raw material to independent sale and marketing
  3. Effect of scale
  4. Internal sources of the development of both technology and strategy.
  5. Management and organization of pro-development.

So far there has not been work on the cultivation process that would include a reduced amount of compost and usefulness of strain from the group U-1 under the conditions of full coverage of nutritional requirements. Evaluating the cultivation process with a reduced compost amount has not been possible to perform due to the technical problems; lack of measures that would allow filling boxes with a substrate in an amount of 50-60 kg/m2. Work on the strain from a group of U-1 has not been carried out because of difficulties to obtain a commercial mycelium.

Within a month, I plan to present my views on the desirability and opportunities to create technologies for growing mushrooms without composting (currently compost in produced in the process of hot composting). This will complete the cycle presenting publications on this website.

11.2014 Harvest and utilization of compost


Mushroom yield is dependent on mature mushroom harvest, i.e. method and organization of harvest under the conditions of fulfilling mushroom feeding requirements and the effective control of pinning and the growth of mushrooms. So then:

  • Mushrooms retain quality longer; therefore the harvesting is easier to organize. This requires the maintenance of an adequate rate of mushroom growth and high concentration of carbon dioxide throughout the harvesting season.
  • Harvesting mushrooms too early reduces the yield in accordance with the rule of 50% weight gain per day.
  • The role of thinning the fruiting bodies and the maintenance time between generations increases. The goal is to preserve the welfare of mushrooms and their dominance in reference to the principle that the stronger and older ones restrict the feeding of smaller and younger mushrooms. This significantly improves the quality.
  • It is very easy to loose the welfare in case of significant changes in microclimate, accelerating the growth of mushrooms caused by presence of collectors and the activities improving working conditions such as blowing cold air on the shoulders, dripping water from the humidification system, etc. The restoration of microclimate parameters is significant. Rapid changes usually cause excessive water evaporation; mushrooms are light and rust discolorations (rust spot) occur on mushroom caps due to water condensation after 2-3 days of storing in a cold room.
  • The first appearance of voids at the interface of the cap to the stipe is the beginning of the welfare loss. They can be seen when cut across mushroom cap. The second sign is a gradual loss of volume weight. The mushrooms are getting lighter and flat, and then a hollow in the middle is being formed.


At present yield sizes that can be achieved in each flush might be predicted.

  • First flush up to 23 kg/m2. It is assumed to be the maximum yield without quality loss.
  • Second flush up to 17 kg/m2. Further yield increase; yield similar to the first flush is planned to be obtained by increasing the dose of carbohydrate and water provided to the compost
  • Third flush up to 7 kg/m2 with prolonged duration up to 10 days. Solving problems with the transition to timely yielding and higher yields should allow further increase of the yields up to 10 kg/m2.

09.2014 Third flush problems

  • Fourth flush 5–7 kg/m2. It is necessary to improve feeding with easily digestible carbohydrates. Cultivation in the hall with a constant microclimate does not allow performing all activities required in the feeding cycle.

Presently an average weekly yield is about 40 kg/m2 and is higher on average by 5-10 kg/m2 than yields collected in the same production system (compost, casing) with protein supplements. Decreased yields during the spring season are due to difficulties of making good compost from very hard straw derived from the 2013 harvest. This situation is a very good time to test the technology based on the process of feeding mushrooms.

Compost utilization

A degree of compost utilization at obtained yield of 40 kg/m2 in three flushes and a load of 83-87 kg/m2 of compost, phase III is 46-48%. It did not exceed 50% but further conducted work should result in higher expected level.

Spent compost

Lack of diseases and pests, and very low sensitivity to further infection, and infestation by pests allows the completion of the production without disinfection. This practice has been carried out at the Chełkowski mushroom farm for years. This is due to the construction of cultivation halls. Non-steamed off used compost is a much better organic fertilizer than steamed off compost. The reuse of compost is a separate issue. The microbiological purity and the development of appropriate technology is the basic requirement for re-using it.

10.2014 Control of the behavior of fruiting bodies and primordia

The observations from last summer and the past winter concerning the behavior of fruiting bodies and primordia on a substrate enriched with corn meal that would guarantee to achieve the planned yield, were the starting point for a debate regarding the control of the microclimate.

The basic observations are:

  1. The size and quality of yields collected during the summer were close to the prognoses. At that time the standard microclimate parameters could not be maintained, thus the standard microclimate conditions could not be created either. The application of higher amounts of water into the substrate was required, as this would reduce thermal effect. Yielding proceeded at higher substrate and air temperatures, air humidity, and a higher concentration of carbon dioxide along with significantly faster air movement.
  2. During winter, upon implementation of the standard microclimate parameters and generally accepted principles of its configuration and reduced dose of water applied in the compost, decreases in the yield and quality of mushrooms were recorded. The yield decrease corresponded to a dose of supplement i.e. higher doses of supplement resulted in larger yield reduction.
  3. At the end of winter, the „summer” microclimate parameters and stimulus changes of selected elements of microclimate, especially the concentration of carbon dioxide (at the level of several thousand ppm) were introduced. This resulted in the return of yielding to the level of 35 kg/m2 in two flushes, while maintaining the welfare of fruiting bodies in the first flush.
  4. During the second flush, the introduction of the summer microclimate parameters resulted in extraordinary pinning without distinction of generations. Despite a satisfactory yield, the need for thinning of fruiting bodies and the high cost of harvesting of small primordia forced the search for the procedure that would allow reproducing generations. A significant differentiation of microclimate parameters that were introduced from few to several hours, in order to stimulate and inhibit fruiting bodies turned out to be a good solution. This effect was achieved by the utilization of different susceptibility of fruiting bodies „strong” and weak (the phenomenon of dominance) to these changes.
  5. Problems in the third flush occurred despite an improvement in the first and second flush yielding.

Conclusions based on the comparison of microclimate and yield between summer and winter:

  1. The overall fulfillment of nutritional needs changed the approach to the effect of the quality of used products (mainly compost) on the yield of mushrooms. The yield depends on the capability of the control of feeding of primordia and balancing the nutritional and water requirements. This implies the necessity to disregard a creation of microclimate parameters as the goalalone. This illustrates the willingness of recreation regarding their course in accordance to the published graphs. Also, an attempt to find one universal solution that would allow creating the microclimate, which repetition in other halls could provide a reproducible yield reflects the same approach as the development of microclimate.
  2. Controlling the mushroom feeding requires precise selection of parameters and/or their combinations as well as their modification in behavior of fruiting bodies and primordia in regards to the change that is expected. These actions must be undertaken from few to several hours before the expected change can occur, mainly in regards to a growth rate of fruiting bodies and primordia in correlation to their number per unit of casing surface in comparison to a current status and expected change. Possibilities of controlling the required parameters by using air conditioning and air movement in production hall should be taken into account, as this would allow controlling the growth of fruiting bodies and primordia. Controlling mushroom feeding by changing microclimate parameters is very effective however; it is not an easy practice.

On the other hand, changes in the microclimate after the occurrence of unfavorable effects, for instance dying out of fruiting bodies, tension membrane under the cap, rupture of stipes, water-soaked spots on the surface and water excess in the fruiting bodies that shorten shelf life, and also flat fruiting bodies with a cavity, a small bulk density, etc., can only further destabilize the expected behavior of mushrooms.

Providing high, stable yields of good quality, under conditions of full coverage of nutritional requirements and control of feeding process requires the development of a separate model of control during the course of mushroom cultivation.

The controlling process includes two stages:

1)      Differentiation of fruiting body generations and small primordia in each flush in accordance with the principle of diversified growth rate of fruiting bodies of first, second and third generation as well as the stronger and weaker.

2)      Maintenance of the growth rate of fruiting bodies in accordance with the process of nutrient transport allowing maintaining welfare (white, shaped fruiting body of high bulk density). Bothgrowth too fast and too slow will worsen the welfare; quality and weight of fruiting bodies. This causes an obstruction between the absorption of water from the casing, transport of nutrients, and weight gain (quality, cell mass and cell membranes). This is the principal mechanism applied in the production process that consists mainly of weakening growth rate by evaporation of water from the surface of fruiting bodies.

Initial assumptions of the control model of the behavior of fruiting bodies and primordia under full nutrient coverage, balanced with accessible water, the nutritional requirements of mushrooms require a new tool that would be able to provide:

  1. An equal movement of air at any place above the casing (micro-sensor system air flow).
  2. A range of measurement of carbon dioxide to 12 000 ppm will be increased. It is worthy to mention that under the conditions of balanced nutritional requirements of mushrooms that the concentration of carbon dioxide in the cultivation hall raises easily.
  3. Measuring the diameter of growth of fruiting bodies with a camera that would further allow the analyzing of the image.
  4. Measurement of life activity of fruiting bodies and primordia by controlling the temperature difference between the casing and fruiting bodies and primordial, and among fruiting bodies and primordia with the thermographic camera.
  5. Measuring the amount of applied and evaporated water by continuous measurement of the weight of the separated section of the crop.
  6. Integration of these variables measurements with the developed algorithm regarding the control of behavioral changes of fruiting bodies and primordia.

It is essential to develop a control algorithm. Observations of mushroom behavior under conditions of complete feeding indicate the need to take into account the following changes occurring between the microclimate and the fruiting bodies and primordia, and in particular:

  1. The influence of stimulus and the changing of the direction of the linear course of microclimate parameters. At phases regarding the differentiating of fruiting bodies and small primordia, small changes of microclimate with considerable variation are required, but for a period of few or several hours in order to give an effect of stimulus – behavioral change. During fruiting, when the course of the parameters should be linear, it is necessary to periodically change the direction (vector) in order to maintain the desired growth rate through a small variation of microclimate parameters with prediction and monitoring the pace and direction of changes. This is to guarantee a transport of nutrients coordinated with the propagation and growth of cells and their walls at the rate imposed by the level of evaporation.
  2. The stimulation of excessive growth of primordia causes intense evaporation and accelerates the transition of primordia to the production of spores. It results in stopping weight increase; flattening and opening of primordia.
  3. Higher temperature of air and substrate. The use of the principle that the rate of life processes increases by 10% as geometric progression at an increase of temperature by 1 ° C. During the growth of primordia the temperature is 19-20 ° C and the substrate up to 23 ° C.
  4. Not increasing the temperature difference between the air and the substrate. Keeping control of the substrate temperature during yielding is dependent on the water content in the mycelium and the substrate.
  5. Increasing the role of carbon dioxide concentration. To maintain the welfare of fruiting bodies a concentration at the level of 2500 to 3500 ppm is required and for some varieties it may be higher. However, to inhibit the growth of fruiting bodies and small primordia, the carbon dioxide concentration at a level close to 8-10 000 ppm is efficient. In addition, it is required to monitor the shape of the bulbous fruiting bodies.
  6. Maintaining a constant water shortage, and not the level of air humidity in the hall cultivation.


Balancing the nutritional needs in accordance to water requirements and with the expected yield does not automatically guarantee success. The system of control of density of primordia, their weight increases at a constant preservation of their welfare needs to be implemented. Controlling the growth of fruiting bodies and primordia is a significant part of the new approach. Balancing the supplement with water is relatively simple, but it determines the further expected course of cultivation. The current knowledge about the control of feeding is the result of practical measures. It will require a broader analysis, based on scientific data and, in consequences, the development of a new algorithm and the tool allowing independently and effectively control the growth of fruiting bodies and primordia through changes in microclimate parameters.

The initiation of primordia is an independent issue, which requires a separate discussion.

09.2014 Problems of the third flush

Two mechanisms of mushroom feeding were considered in the implementation of the concept of controlled mushroom feeding. The first mechanism refers to a direct feeding by the enzymatic degradation of dead organic substances when the obtained nutrient ingredients are collected in the mycelium. Their amount plays a significant role in the production process and affects the yield in the first and second flush.

The second mechanism is the indirect feeding, consisting of the absorption from the compost easily soluble nutrients produced during the cold composting (commensalism). Thus, nutrients dissolved in water are transported through the mycelium to the fruiting bodies and therefore affect the yield in the third and fourth flush. The change of the feeding method results in substantial yield decrease. The average yields from these flushes do not exceed 5 kg/m2. This situation raises the question as to whether the yields in these flushes, particularly the third one can be increased up to 10 kg/m2. Two hypotheses were examined. The first one assumes that yield gain can be achieved through an increase of nutrient stocks during the direct feeding. It should guarantee the yield at the level of 40 kg/m2 in two flushes and additional 5 kg/m2, which in total could provide the yield of 50 kg/m2 in the third flush. So far this concept has failed. An increase of nutrient stock could not be balanced efficiently with water, which was required to complete requirements of higher dosage of corn feeder. The compost was not able to absorb more water therefore the increase of water amount could have resulted in compost decay. Not balancing water needs caused a yield reduction due to the drying out of compost. The obtained result was opposite of the planned goal as the yield in the third flush decreased. As the second flush yield increased above 17 kg\m2, a short-term retention of fruiting body growth occurred on the casing surface and caused a delay of their emergence from the deeper layers. This situation resulted due to the dying out mycelium on the casing surface during the second flush that was caused by the casing drying out. The production stabilized yielding (5-6 kg/m2) in the fourth flush when the fruiting bodies developed normally. Regarding this situation the second hypothesis of using a standard amount of corn feeder was tested. This approach assumes that the yield can be increased by an addition of monosaccharides and citric acid into casing. Also, in order to stimulate the growth of fruiting bodies an effect of changes of microclimate, mainly lowering an air temperature would enhance growth of fruiting bodies allow the obtained generations to be tested. The first results indicate that this approach might work and would help to collect additional yield above 5 kg/m2 in the third and fourth flush up to a predetermined limit of 10 kg\m2. It still requires some improvement and gradual implementation throughout the plant where the mushroom production and tests are carried out.

The development of this first concept has not been given up. These efforts to increase the compost water capacity and also using the possibility of soaking water placed in the bottom of the box lined with tightly foil have been undertaken.

08.2014 Casing

Colonized substrate that contains sufficient volumes of water and nutrient ingredients will not guarantee high yields if casing does not support the feeding process. Several performed tests followed by the implementation of the concept regarding controlled mushroom feeding provided data that lead into the conclusions describing conditions that are required so that casing will not decrease expected yields. It is obvious that the casing must have a uniform composition and structure, and should be evenly applied; not higher than 5 cm. The intense production requires medium or heavy casing. Light casing is not recommended due to its low water holding capacity. The specific requirements supporting the process of feeding besides water holding capacity are the following:

  1. Water shortage can not occur between casing application and end of the production process. Casing should be “shiny”, not matt. Water deficit causes mycelium drying and fruiting bodies, and in consequence a considerably decrease in the number of fruiting bodies particularly in the second and third flush. Water shortage worsens the quality of fruiting bodies, deprives their color and reduces yield by decreasing unitary weight: fruiting bodies are light. The mycelium should be white and alive on the casing surface during the entire production period. The addition of water into casing is easy, despite the growth stage of fruiting bodies irrigation will not worsen their quality as their nutritional requirements are fulfilled and their growth is controlled.
  2. Dry bubble disease (or brown spot) develops more intense on weakened and yellow mycelium.
  3. The casing must have a much higher salinity that is presently recommended and maintained, and it should be sustained at the same level throughout the entire period of cultivation. Appropriate salinity improves the quality of fruiting bodies and the yield by an increase of their mass and also pinning during flush is easier and more reproducible. Under these conditions the fruiting bodies are not exposed to short-term retention of their growth and respond better to activities aiming at the development of different generation stages. The salinity can easily be controlled, as there is a method, which allows taking direct measures from the casing. Effects of stable and higher salinity on mushroom yields in the third and fourth flush are expected.
  4. Stable calcium content. Research studies indicate a significant role of calcium in the feeding. The performed tests confirm the usefulness of calcium chloride in the feeding process. First, the pH should be stabilized as its decrease can enhance a risk of green mold occurrence on the casing surface in the third and following flushes. It is probably easier to fulfill calcium requirements of fruiting bodies if its source is provided in the casing. The transport time is shorter than that from the substrate. Besides, often application of calcium chloride induces a reaction with concrete and causes sealing concrete pores. This significantly reduces the risk of survival of spores of causal agent of dry bubble disease, as the concrete is the main source of infection within the cultivation hall.

Two-layer casing

So far the individual tests with the two-layer casing were performed. The collected results indicate that it might be a potential useful solution. An application of a hydrogel filled with liquid nutrients is a new idea that will be soon examined. This should create conditions supporting more sufficient colonization of the casing and better connection of mycelium with the substrate, and also shorten transport of components into fruiting bodies and primordia.

07.2014 Green molds and mushroom feeding

Green molds are the most important pathogens infesting substrate in the mushroom production. Their presence and the development of their colonies still present the potential cause of the most serious losses. I have been interested in this problem since early 2000. In Poland, the highest losses resulting from green molds infections occurred in the years 2002 – 2009. In 2009, I published the book “Green molds in mushroom production” (PWRiL) regarding this topic.

Presently, two genera of fungi, which are considered the green molds, are described as the main causes of losses in mushroom production. The highest losses result from infections by the genus Trichoderma, particularly by Trichoderma aggressivum. The recent data indicate potential serious threats from other pathogen Penicillium hermansii (smoky mold) Hermans C., Houbraken J., Smokey Mould: the smoke screen lifts, Mushroom Business, 061 November 2013. Both these species (strains) share one feature i.e. they are considered the aggressive mushroom pathogens.

How can one characterize a current concept of losses caused by the green molds that develop in the compost and infect mushrooms?

This theory assumes the existence of a correlation between the presence of spores of pathogens such as Trichoderma aggressivum and other species of Trichoderma spp. with competitive behavior and the smoky mold (Penicillium hermansii) in the compost, and also the development of their colonies as the result of infections with spores or mycelium, and destabilizing the selectivity of compost. This hypothesis can also be illustrated in other words i.e. colony size might be larger if more spores of pathogens survive during the compost production process and the compost is less selective. The losses resulting from the primary infection are the most severe particularly if colony development occurs in the tunnel. Whereas the secondary infections that happen between the completion of compost phase II production and at spawning until applying casing cause much less losses. It means the early and severe infections while the compost is less selective results in higher losses.

Despite numerous scientific studies there are no satisfactory results that would help solve the problem regarding how to protect the compost against infections of mentioned above pathogens. This situation becomes more difficult as a current problem of losses caused by Trichoderma aggressivum disappears in itself and the smoky mold does not indicate an increasing threat. There is no information regarding new green mold infections. Personally I have seen the infection with smoky mold several times over 20 years of my consulting practice. For instance, in the past the smoky mold infections were observed occasionally and did not cause significant losses. They are not perceived in many countries with the mushroom production. Regarding this situation one can ask the question if this problem solved itself and forever? Will we experience new infections in the coming years? If the infections do occur, how do we prevent the losses? So far there is no satisfactory answer.

Preparations of the concept regarding development of mushroom production technology as controlled feeding and its implementation requires additional review of this issue. Solving the problem of yield losses caused by the green molds considers two potential possible approaches.

  1. The first approach would exclude using compost in the mushroom production that would eliminate primary infections. Instead of the compost it is recommended to apply a substrate within control of its microbiological environment; lack of primary infections and protection against secondary infections by the simultaneous introduction of mycelium and casing application.
  2. The second approach considers changes in a feeding process that would protect the mushrooms against secondary infections and minor primary infections. In this case the compost plays the secondary role in a mushroom feeding. Properly composed feeders create conditions for full control of microbial composition of compost during its recolonization after their addition into a substrate phase III. The mycelium will become so strong that it will not allow pathogens to develop and compete for nutrients. The nutrient competition and pathogen presence are a main cause of losses in mushroom production. This means necessity to provide a surplus of mushroom mycelium during the recolonization process and during feeding after the casing application that a minor primary infection will not occur, and in consequences secondary will not take place either at a stage of placing on the shelves. This is a significant advantage regarding dominance over nutrients and competitors that might be present in the compost. This proceeding should be efficient enough. This approach is based on two assumptions that are accepted as legitimate. Although the genus Trichoderma and Penicillium are the competing species and more opportunistic towards food source that the mushroom, they show different food preferences. They utilize protein better than the mushroom, suggesting that there should be lower protein content in mushroom feeding. The second approach assumes that these species are not aggressive and they become destructive only in certain environmental conditions, and this aggressiveness is transmitted into another environment via vegetative way. Aggressive behavior occurrence among competing species has already been reported and it is not very rare phenomenon. The question is what causes this aggressive behavior. The following factors might be the deciding elements: colony size of pathogen, disruption in compost selectivity and process of compost colonization by mycelium. What is the reason that aggressive species and aggressive behavior have been discussed? It results from the fact that I have never observed secondary infections with Trichoderma aggressivum in places that had prior infections. It confirms that secondary infections do not occur in production facilities with high hygiene procedures that include steaming after compost production and also in facilities with very low hygiene without steaming measures. These observations refer to hundreds of reported cases. In contrast the losses caused by dry bubble disease (or brown spot) show a clear correlation between hygiene practice and the level of colony development of this pathogen. Performed observations indicate that a diet based on high polysaccharidecontent results in very rigorous expansion of fungous in the compost and that inhibits Trichoderma and Penicillium infections that might take place during the placing of substrate phase III on shelves.

I am interested in both solutions.

However, the pathogens might colonize the supplements and cause significant losses in production if these supplements based of vegetable origin, such as ground corn, are improperly prepared and stored.

A separate aspect is a potential mushroom strain that would be resistant to the green mold present in the compost. In my opinion, it is difficult to count on such a solution mainly due to the difficulties of identification of genes that should be modified to obtain such a resistance. Besides, finding these genes is one problem and another one is an implementation of genetically modified mushrooms into production and acceptance among producers. Presently the resistance can only be achieved in the genetic modified material and that also requires funds and executor. The current lack of real threat to mushroom production yield makes this issue of little interest among mushroomproducers.

06.2014 Water in compost and feeding

Water availability in compost should go through a review due to the implementation and development of the controlled mushroom feeding concept. The amount of available water must be significantly higher than in mushroom production that provides yields in range of 30-32 kg/m2 in three flushes.

All things considered, an important factor for good production appears to be water availability in compost that is reffered to as active water or built into compost water. Currently the active water plays a significant role primarily in the compost production phase. Stored water; built into compost water source is not sufficient to achieve high yields of very high quality mushrooms. Water shortage increases when thermal effect occurs in the compost. High temperature and necessity of intense cooling decrease the amount of water availability during the feeding process.

Compost moisture content during its production phase III cannot be increased above 67-69% due to the risk of incorrect course of production process. Water excess, particularly not built into compost during phase I causes disturbances in a balance of oxygen and proper course of the phase called hot composting. It can result in developing anaerobic environment. In turn in the wet compost phase II it is difficult to control a required compost structure during stage of overgrowth in tunnels or yielding spaces such as shelves, boxes, blocks. The compost with long period of cultivation creates the most difficulties. This favors the process of rotting.

High yields require absolutely much higher amounts of water availability for mycelium rather than currently used after placing a casing layer. This can be achieved in a correctly prepared compost, particularly if straw is loose and pliable with good structure and without the presence of competing and pathogenic organisms. These high water amounts are used in feeder enzymatic degradation and transferred into mycelium from substrate. The transfer of water into mycelium protects compost from rotting and overheating. Water shortage causes dryness of the compost.

The time period during which water is added is relatively short, less than 3 days after the recolonization and achieved compost temperature min 23oC with a trend of increase. The process of adding water should be performed after blocking air availability; placing casing. Water dosage should be determined in relation to the expected yield based on the rule 2 l/m2 and introduced feeder dosage. Presently, feeder dosage has been established for processed corn grain. The schedule of adding water must be established individually for each compost. It needs to include both its quality and quantity, and dosage and type of feeder. One can not forget that the added feeder absorbs water equivalent to its wage.

Lack of a balanced feeder dosage associated with deficiency of water availability will negatively affect the mushroom production. It will result in yield decrease and worsen its quality more than without a feeder.

All tests and cultivation are carried out on a substrate made of straw and chicken manure without horse manure.

05.2014 Condition of mushrooms after an application of a maize meal as a supplement.

During the first phase of the introduced changes that were examined at the Chelkowski Farm, the supplements based on soybean meal used in the past were substituted with soybean meal prepared according to the developed own recipe. The new product was applied at the same rate i.e. 1.5% mass of substrate phase III, the same amount as others available supplements. The completed observations were implemented in further tests, which goal was at increase in yield in three flushes up to 40 kg/m2.

The most important findings are as follow:

  1. Quality improvement of primordia in the first and third flush. It was then when a concept of well-being (fruit bodies welfare) was developed. The obtained yields varied from 32 to 35 kg/m2 despite variable cultivation conditions and both quality and quantity of purchased substrate and casing layer. The yields at this level were achieved when provided substrate and casing layer were a very good quality. The level of production in a range of 25-27 kg/m2 that was observed on other mushroom farms who used the products from the same supplier was not considered as a reduced yield.
  2. Mycelium regenerated faster and the mycelium turned white sooner.
  3. Temperature increase in the substrate after an application of a casing layer was easy to control. If local overheating took place, the inner part of the substrate did not decay and there were no signs of green mold growth, which were observed when the supplements containing soybean meal were used. Overheated substrate was dry and loose. The mushroom kept producing primordia although the substrate surface has been collapsing in the following weeks. Red pepper mites did not show up.
  4. Periodically, shock could be initiated 5-6 after an application of casing layer.
  5. The substrate producer provided a compost of phase II colonized with two strains of fungi that resulted in better results. Over pinning was easily avoided and the improved quality of fruiting bodies of the more demanding strain, that was related closer to the strain from a group of U-1 was observed.
  6. Occasionally water shortage in the substrate was noticed, particularly when the substrate characterized low moisture and too hard straw, which was caused by poor removal of a wax layer and it resulted in blocking water access.
  7. Waving eelworms were found on the surface if either incorrect granulation of meal was applied or improperly mixed, and when large quantities on meal occurred between the casing layer and the substrate.

The positive results obtained from the implementation of the controlled mushroom feeding with an application of a feeder allowed gradual increase in its dose and extension of cultivation period up to four flush.

04.2014 Colonization and recolonization of the substrate and mushroom feeding

The growing period during which the mycelium grows throughout the compost and the casing layer is known as the vegetative phase and must precede a feeding process. The vegetative growth refers to the colonization and enzymatic degradation of the substrate inhabited by a mushroom. The colonization occurs from the moment during which the mycelium contacts its surroundings, and ends when the colonized environment is fully overgrown. First, available environment structures i.e. compost and casing layer get covered by mushroom mycelium. This period is relatively short and usually takes about 3-5 days. The colonization rate depends mostly on the ratio of mycelium volume to the volume of the occupied environment, as well as the availability of usable carbohydrates, moisture, structure and temperature.  During colonization a gray mycelium develops covering substrate or casing layer and subsequently changing microflora within feeding environment.  The changes happen in two independent courses of action, the biosupression that is an elimination of unwanted microorganism, particularly antagonistic microorganism and the commensalism, which is a process favoring development of useful microorganisms, mainly Scytalidium thermophilum – in the substrate, and Pseudomonas putida – in casing. The entire process is dependent upon carbon dioxide content and the amount of hydrogen peroxide production. A feeding process begins when enzymes become active.  At the beginning of the process obtained nutrient ingredients are used to continue mycelium growth in order to control environment. Subsequently, nutrient ingredients that are obtained from enzymatic degradation and their transport to fruiting bodies cumulate in rhizomorphic mycelium (white, thick strings). This phase is considered complete with a transition into generative phase, and forming fruiting bodies stage begins.

The producers address the important question in regards to the duration of the time required for compost colonization that would provide the highest yields at well-balanced feeding conditions.

To achieve the best results the following conditions should be provided.

  1. The colonization period should be short. Only fully colonized compost can be an effective source of substrate nutrients in enzymatic feeding. The duration of compost colonization by mycelium is a very important feature, which allows evaluation its selectivity. Quick colonization protects the compost against the development of unwanted, competitive organisms. Based on the conducted tests it has been concluded that the presence of soluble carbohydrates and the amount and form of used mycelium are the most significant factors. Shorter colonization time results in extended enzymatic feeding at the constant mycelium growing period. At the same time, loose and pliable straw creates a larger surface, which increases mushroom enzymatic activity.
  2. Potential yield of fruiting bodies is determined by the mycelium mass developed in the compost. Consecutively the mycelium mass depends on a length of carbohydrate chains, that need to be degraded, amount of decay fungi in the compost and size of mycelium surface contacting compost. Cellulose, the main component in straw, is the most difficult element in enzymatic degradation. The process of starch degradation is much slower.  The increase in mass of rhizomorphic mycelium depends on the compost structure as well.
  3. The temperature range of 23 – 27oC and high CO2 concentration support the quick compost overgrowth by mycelium.
  4. The duration of the compost overgrowth process under production conditions is 12-18 days. Regardless of the unchanged length of overgrowing stage, this process can affect the yield level. In principle, a period that is too short will cause destruction in the process of biosuppresion and commensalism and there is a risk that none of them will complete. Therefore, the competing organisms will develop sooner and the temperature effect will occur. If the ingredients contained in the substrate are difficult to assimilate, the overgrowth period should be longer. Can this period be too long? A decision regarding when to end a digestion process and unwanted energy usage is difficult to make. Under the laboratory conditions mycelium mass has been growing up to 45 days.


It might be worthy to consider the introduction of a new term – recolonization, it is second growth of mycelium after breaking the compost removed from a tunnel or after mixing the compost on a shelf – at overgrowth phase II in production hall. This period is relatively short, 2 – 4 days and it depends on the existing temperature, water application and CO2 concentration. Compost density is also very important. Excessive compaction of the substrate makes it difficult to increase its volume while too poor makes it difficult to control the temperature in the substrate during shock (aeration).  Regarding further feeding, especially when introducing feeders, the control of the course of aeration is very important. Throughout this period, water is applied to the compost, and the thermal effect is controlled. Improperly applied water, along with air, low concentration of carbon dioxide in the compost and the absence or late reaction to the start of the thermal effect results in high substrate temperature increases. This causes a disturbance in feeding or in extreme cases leads to the overheating of compost.

Casing colonization

When fulfilled feeding is provided and water is well balanced in the compost, mycelium develops better and does not continue vegetative growth despite starting a shock. Thus pinning is easier. The colonization of casing and its role in feeding, particularly in cultivation without compost, and application of two layers will be examined after the establishment of a substrate content and an evaluation of substrate conditions without compost, based on fixed feeders.