NEW: What about 40kg/m2

Biuletyn producenta Pieczarek PIECZARKI 3/2017  S. 28-32

What about 40kg/m2

dr Nikodem Sakson, Poznań

During the Pieczarkalia Mushroom Festival in 2014 a concept of developing the technology of production of mushrooms on fresh market was presented. The goal was to reach the average yearly level of yield of 40 kg/m2 in three flushes. At the time of formulating this goal a yield of 32 kg/m2 in three flushes on phase III substrate with the average amount of 85 kg/m2 with 1,5% of protein supplement in one dose was considered good enough both in Poland and in Netherlands. This issue of Bulletin is supposed to be published after Pieczarkalia 2017. It is a good moment to present the results achieved from implementing changes in technology and further perspectives of its development.

Searching for a cost-free increase in yield is the result of the fact that the prices of mushrooms have been constant for several years. Despite the increase of production costs, the prices that producers get from their clients are still the same. Increase in the yield without the increase in cost of production is the only way to maintain or improve profitability of mushroom cultivation in Poland. Both several percent increase of consumption of mushrooms in Poland and 2% increase in Europe haven’t changed this situation.

Presentation of the concept of technology that would allow achieving yield on level of 40 kg/m2 during Pieczarkalia 2014 was accompanied by amusement and ridicule, which were the result of the fact, that this goal was considered unrealistic in situation when Dutch producers didn’t improve their technology and didn’t increase their level of yield. A good reception of this concept wasn’t helped by the fact that I connected it with a question whether it is possible to produce mushrooms without traditionally produced substrate. Also intention of using starch feeding supplement (based on grains of wheat, mainly corn), is against the interest of several companies specialising in supply of materials to mushroom farms. These are not factors that would work in favour of good reception of Authors actions.

Describing the state of this technology, three questions have to be answered.

What was achieved thanks to implementing changes into the technology of mushroom growth and what changes where implemented?

In 2016 on a total area of 16 000 m2 an average yearly yield of 36 kg/m2 was achieved in three flushes of mushrooms for a fresh market. On every mushroom farm the yield of 40 kg/m2 was exceeded several times during the year. Here I would like to thank those, who took a risk in verification of proposed changes in technology – Mushroom Farm Chełkowscy, especially Mariusz Chełkowski and Zbigniew Marczak, and company Aril, especially Dorota Chmielewska, who took on producing feeding supplements. Without their involvement, those results could not be achieved. They were achieved by implementing following technological changes:

  • using Aril feeding supplement to substrate and casing soil in dosages – to substrate – up to 2,7%, and 150 g/m2 to casing soil,
  • high dosages of water to substrate without any spills were used,
  • controlling the thermal effect,
  • controlling evapotranspiration, by its measurement, using Piche’s evaporimeter in one case, and water deficit in the second (absolute humidity with high level of changes of carbon dioxide and maintaining minimal air flow and system of watering the flooring),
  • substrate’s activity between flushes was minimalised, maintaining constant difference of temperature between the substrate and air for the whole period of yielding,
  • controlling the spread of the flush and density of fruiting bodies, using mentioned above systems of controlling evapotranspiration
  • controlling the volume weight of fruiting bodies, using the controlled evapotranspiration during cultivation,
  • losses caused by diseases and vermin were eliminated

All of the topics were the subject of publications in Bulletin.

Is the goal realistic?

The goal of achieving yearly average yield of 40 kg/m2 in three flushes can be considered a realistic one. Both in Poland and abroad the yield above 40 kg/m2 was achieved sporadically. We want to achieve the same goal using different kind of feeding supplements by company Nutrigain. The results of the last tests indicate that there is a possibility to achieve the level of yield reaching 45 kg/m2.

What is next?

Further increase of yield over 36 kg/m2 is connected to solving the problem with maintaining maximum volume weight of fruiting bodies during the whole yield of all the flushes and increasing yield in the third flush. At this moment it is impossible to increase the yield in the first and the second flush by increasing the number of fruiting bodies. The reason for this is that – because of limited number of workers for picking mushrooms and because of the increasing cost of picking – the only acceptable solution is not allowing for too many buds to bind. There is a necessity of spreading the flush by manually removing the excess of small fruiting bodies. The heavier the fruiting bodies, the bigger the harvesting efficiency is. The volume mass and the ability to maintain it after the harvest depends on the number of cells in the fruiting body and on constant accessibility to water. The bigger the number of cells, the higher the volume weight and the longer it is maintained after the harvest. The fruiting bodies can be heavier too, if one can introduce water between the space of the cells (stopping the evaporation), but the quality and durability of those fruiting bodies is low.

The number of cells depends on accessibility of nutrients in the mycelium and their transport and accessibility of micro- and macro elements which regulate the process of using carbohydrates, mushroom’s main building material and its source of energy. The tests with TOP VITAL 7 and TOP VITAL 8 are conducted to reach those goals. They should allow increasing the level of yield for minimum 5% or more and stabilizing them.

Transportation of nutrients is a significant setback in maintaining high volume weight of fruiting bodies, especially in the second and the third flushes. That is why we were trying to achieve different arrangement of nutrients in casing soil and substrate underneath, so the transport would be the shortest. Answering the question whether this assumption is true or not is limited because of lack of technological possibilities of this kind of arrangement of feeding supplement in substrate.

Another issue is the question why can such different yield on substrate from its different batches and from different producers occur? I will return to this question in the next issue of Bulletin.

There is still lack of progress in increasing the yield in third and sequential flushes. The problem occurs because mushrooms feed using the different method at this period. In this flush Agaricus uses the nutrients that were dissolved in the water, and were produced by microorganism that continue the process of cold composting of the substrate. At the moment there are no possibilities of testing the solutions to this problem. Maybe a supplement to a phase III substrate, especially prepared used substrate after cultivation, can be a solution.

Improvement of availability of nutrients, leads us to search for races of mushrooms with a higher nutritional requirements, which would give higher yield. There are no typical races of group U-1 mycelium on the market. Only races that are similar to this group like E-58 Premium, VIP, Magnum, or Triplex are available. They are still waiting for their place in the mass production. To achieve this, substrate containing those races should be delivered only to this producers, who are able to provide them with required conditions.

An issue that wasn’t solved in a satisfactory way is the danger of green mould occurring, caused by Penicilium mushrooms in the third flush. The result of which is development of buds on fruiting bodies in a form of brown spots. Jos Hilkens in the issue 39 (20017) of “Mushroom Business” as a cause of this problem considers: “(…) the remains of the mushrooms, underdeveloped or dead parts of susbtrate, sometimes feeding supplements, which get into substrate from casing soil by CACing, or are deliberately placed in the casing soil.” When spots of green mould occur on a casing soil it is necessary to isolate them by covering them with paper towels dipped in a solution of disinfectant. It is recommended that the concentration of carbon dioxide is very low, about 500-600 p. p. m. during the period between the ends of harvest of the second flush till the beginning of harvest of the third flush. Creating such conditions isn’t hard, taking into consideration low activity of substrate which is the cause of small production of carbon dioxide in this period. It is necessary to control the weight of the fruiting bodies, the activity of substrate and to match the level of evapotranspiration to these conditions by regulating relative humidity. We are searching for other forms of feeding supplement used for casing soil, and we block the movement of pins of Penicilium with water or air, protecting from losses that result in development of green mould on a surface of casing soil. Another solution can be resigning from harvesting the third flush and concentration on achieving level of yield of 18 kg/m2 in the first and second flush, so limiting the goal to 36 kg/m2 with using feeding supplement in casing soil.

The effect of proposed technology is higher usage of starch feeding supplements in the last months. It allows reducing the cost of production, which is especially noticeable on big mushroom farms.

Photo. 1. Tests with liquid feeding supplement to the casing soil – high shelf.

Photo. 2. Tests with drip irrigation on the whole cultivation area.

Fot. 3. Another tests with vermiculite

Polska wersja artykułu / Polish version