METHOD AND APPARATUS FOR GROWING FUNGI

Abstract: The invention relates to a method for growing edible toadstools, comprising the steps of: a) arranging a nutrient layer in a growing space, b) arranging mycelium in the nutrient layer, c) cultivating the mycelium to toadstools, and d) harvesting the toadstools, wherein the nutrient layer arranged in the growing space is substantially compost-free. The nutrient layer can be formed by arranging on a relatively thin compost layer a moisture-absorbing layer whereof the thickness amounts to at least half the thickness of the compost layer. It is even possible for the nutrient layer to be formed solely by a moisture-absorbing layer. While in this way the yield of the culture is reduced, the raw material consumption is reduced even more sharply, whereby the specific yield therefore increases. The invention also relates to an apparatus for performing this method with a frame for placing in a growing space which is provided with a number of substantially horizontal carriers for a nutrient layer placed one above another, which carriers are arranged in the frame with an interspace of less than 40 cm in vertical direction. The carriers can herein be arranged movably in the frame. In this manner the toadstools on the carriers can be harvested outside the growing space. A space-saving is hereby achieved.

Description: METHOD AND APPARATUS FOR GROWING FUNGI The invention relates to a method for growing fungi, in particular edible toadstools, comprising the steps of: a) arranging a nutrient layer in a growing space, b) arranging mycelium in the nutrient layer, c) cultivating the mycelium to fungi, and d) harvesting the fungi . Such a method is known and is generally applied for instance in mushroom farming. In the known method a culture tray arranged in a rack is filled with a layer of compost of for instance 20 cm, in which is arranged a nursery material designated as mycelium, whereafter the whole is covered with a layer of earth of several centimetres. The rack with culture trays is situated in a climate-conditioned growing space. After a period of about 4 weeks sufficient mushrooms have been grown from the mycelium to enable a first harvest. This takes place mechanically or manually, depending on the desired quality of the mushrooms. Because the compost layer is a very fertile nutrient layer for the mycelium, the latter still has sufficient vigour after the first harvest to make one or more additional harvests possible. These harvests take place at an interval of about a week and have a successively decreasing yield. The culture trays remain in the growing space until after the final harvest, and harvesting therefore takes place while the culture trays are situated in the racks. Sufficient space must therefore be created between the culture trays to enable the harvesting operations to be carried out. The total yield of the mushroom cultivation as according to the above described method amounts to roughly 20 to 40 kg/m 2 or more (50 kg/m 2 ) . In a variant of the above described growing method the culture trays or cases are placed loosely in a rack and for each harvest are taken out of the rack and carried outside the growing space using for instance a fork-lift truck. Here the mushrooms are harvested, whereafter the cases are taken back into the growing space and re-placed in the rack until the following harvests. Here also therefore, sufficient space must be left clear in the growing space to enable manoeuvering with the culture trays, while repeated displacement of the culture trays is moreover time-consuming. The above described methods have in common that they are comparatively costly due to the relatively high raw material consumption and the large amount of space taken up. In addition, these methods generally require the use of pesticides, which is undesirable from a public health viewpoint. Finally, with the known method it is possible only with great effort to maintain the temperature in the growing space within a desired range. The invention therefore has for its object to provide an improved growing method. According to the invention this is achieved with a method of the above described type in that the nutrient layer arranged in the growing space is substantially compost -free . While as a result of making hardly any use of compost the yield of the culture per unit area is smaller than in the conventional method, the raw material costs are also consider- ably lower. A single harvesting will moreover suffice in this method, which harvesting can therefore take place outside the growing space, whereby the space occupied by the culture trays is considerably smaller. Furthermore, because the fungi are harvested before the vermin specif- ic to such a culture is fully grown, the use of pesticides can be dispensed with. Finally, the temperature in the growing space can be controlled better in the method according to the invention, since it is particularly the compost which generates a relatively large amount of heat . Through control of the temperature in the growing space the moment of harvesting can moreover be adjusted precisely, whereby the workload of a grower can be properly spread. Preferably applied variants of the method according to the invention are described in the sub- claims 2-10. The invention also relates to an apparatus for growing fungi with which the above described method can be performed. Such an apparatus, which comprises a frame for placing in a growing space which is provided with a number of substantially horizontal carriers for a nutrient layer placed one above another, is characterized according to the invention in that the carriers are arranged in the frame with an interspace in vertical direction, and the interspace is smaller than 40 cm, and preferably smaller than 30 cm. This small interspace can be achieved because no side edges are required along the carriers due to the small thickness of the nutrient layer. The growing space is utilized optimally by making use of carriers received in the frame with small interspacing. By placing for instance four times as many carriers above each other as would be possible in the conventional culture methods, the decrease in yield resulting from the omission of the compost nutrient layer is already partially compensated. Preferred embodiments of the apparatus according to the invention form the subject-matter of the sub-claims 12-15. The invention will now be elucidated on the basis of an embodiment, wherein reference is made to the annexed drawing, in which: fig. 1 shows a perspective detail view of a nutrient layer which is arranged on a carrier and which has therein fungi which are grown according to the method of the invention, and fig. 2 is a perspective view of a part of a growing apparatus according to the invention. In the culture method according to the invention a nutrient layer 2 is arranged in a growing space l (fig. 2) . A nursery material for fungi, known under the name mycelium, is then placed in this nutrient layer. This mycelium is then cultivated to produce fungi 3 which can subsequently be harvested. The method according to the invention is herein distinguished from the conventional methods in that no or hardly any use is made of compost for the nutrient layer 2. In the shown embodiment the nutrient layer 2 is formed by a very thin compost layer 4 of for instance 1 cm, onto which is_ arranged a thicker layer, here for instance of about 2.5 cm, of moisture-absorbing and retaining material 5 such as for instance top soil (fig. 1) . According to the invention the thickness of the moisture-absorbing layer amounts to at least half the thickness of the compost layer, but is preferably equal to the thickness of the compost layer or, even more preferably, amounts to twice this thickness. By hardly making use of compost the mycelium has less nutrition available, whereby the yield of fungi 3 per unit area will be relatively low. Surprisingly however, it has been found that this relatively low yield enables shorter growing cycles, whereby this drawback is already partly obviated, while less space can moreover be taken up in growing space 1. In addition, no or hardly any use need be made of pesticides in this new growing method. Because the yield per unit area is relatively low in the new growing method, it is possible to suffice with a single harvesting. This harvesting, which can take place about 3 to 4 weeks after the beginning of the growing cycle, produces for instance a quantity of fungi of 2 kg - 5 kg/m 2 of nutrient material. Because only one harvest is required, harvesting need not take place in the growing space 1 itself but can be carried out outside. The nutrient layer 2 can be arranged for this purpose on a displaceable carrier 6, for instance in the form of cloth 7, for instance nylon cloth, slidable on a board 16. Because the fungi in growing space 1 do not have to be accessible for harvesting thereof, these carriers 6 can be arranged with relatively small interspacing in a growing apparatus 8. This growing apparatus 8 herein comprises a frame 9 formed by a number of uprights 10, a number of longitudinal girders 11 and a number of transverse connections 12. Carriers 6 are placed with interspacing one above the other in this frame 9. Because only a very thin nutrient layer 2 is arranged on carriers 6 , the frame does not have to have any standing walls or side edges. This interspacing between two carriers 6 placed one above the other can thereby be less than 40 cm, and preferably less than 30 cm. The interspace more preferably even amounts to less than 20 cm, for instance 15 cm. In this manner a large number of carriers 6 can be placed one above another in frame 9, whereby a considerable quantity of fungi 3 can still be cultivated and harvested per unit area in growing space 1. A frame which can contain for instance 5 layers of carriers with use of a conventional growing method is able to accommodate 20 layers of carriers with use of the method according to the invention. A relatively large amount of space is further required around the carriers in the conventional growing method in order to enable interim harvesting in growing space 1, whereby fewer racks with carriers can be placed adjacently of each other. The movable carriers 6 are formed in the shown embodiment by strips of nylon cloth 7 which are slidable over the boards 16 of frame 9. For harvesting use is herein made of a harvesting device 13 which consists of a portal 14 which is displaceable in the direction of arrow D between guide rails 15. Portal 14 has a table 23 with a winding roller 21 which is driven by a motor 22. The portal can be displaced upward and downward by means of a winding motor 18, whereby two suspension cables 17 are paid out or hauled in. In portal 14 are further suspended rotating knives 20 driven collectively by a motor 19. It is also possible to apply translating knives. Other knives can of course also be envisaged, such as for instance two flat knives which are placed one above the other and movable reciprocally in opposing directions and which extend over the whole width of the cloth. For harvesting the portal 14 is displaced such that table 23 lies in the line of one of the carriers 6, whereafter the cloth 7 present thereon is connected to a lead-in strip fastened to drum 21 and drum 21 is then rotated by motor 22, whereby cloth 7 is pulled from board 16 onto table 23. The knife 20 is herein moved reciprocally in transverse direction of the cloth strip, whereby the fully-grown fungi 3 protruding above the nutrient layer 2 are cut off. These are then discharged via a belt 26 extending in transverse direction and provided with carrier members and a cross conveyor 24. When the cloth is wound up nutrient material 2 falls onto a laterally placed conveyor belt 25 and is discharged in the direction of arrow S in order to be disinfected and made suitable for reuse or to be disposed of . In this manner the nutrient layers 2 with fungi 3 can be removed successively from all carriers 6 and the fungi 3 thereof harvested. ~ The apparatus can otherwise be made suitable for manual harvesting of fungi 3. For this purpose the table 23 is then lengthened by a few metres, while knife 20 can be omitted. Along the table 23 extended to form a picking line one or more passageways or benches can then be placed on which a number of pickers can stand or sit. At the end of the picking line a cross conveyor 25 is again then placed for discharge of the nutrient material . Preparing the apparatus 8 for a following growing cycle takes place in similar manner. A lead-in strip is herein also connected to a fresh strip of nylon on which nutrient material and mycelium is then spread before cloth 7 is pulled into frame 9. Both harvesting and filling of the apparatus 8 with new culture material therefore takes place from the ends of frame 9, whereby the space taken up is minimal . Growing space 1 can thus be very densely filled with carriers with culture material. As stated, roughly four times as many carriers can be placed one above another compared with the conventional growing method. Racks 9 can moreover be placed with smaller interspacing, whereby the total yield of growing space 1 is still practically the same as in a conventional growing method despite the fact that hardly any use is made of compost . Furthermore, the raw material costs are considerably lower because less relatively expensive compost, or none at all, is used. Nor are pesticides required, or hardly so, since the vermin specific to fungi has a growth cycle roughly the same as the growth cycle of the fungi, whereby the vermin does not develop before the fungi are harvested. In conventional growing methods full use must be made of pesticides, particularly during the second and third harvest, since at that moment the vermin has developed. Finally, cultivation can be better controlled with the method and apparatus according to the invention and less equipment is necessary to condition the climate in growing space 1. This is a result of the fact that compost develops heat, whereby the growth of the fungi is indeed accelerated but it also becomes more difficult to maintain the required temperatures in the order of 17 or 18 °C in growing space 1. By making hardly any use of compost the temperature can be readily controlled and the growing process can thereby be regulated such that harvesting is not necessary for instance at weekends or outside normal working hours . The workload for the grower can hereby be spread and the cultivation costs limited still further.

Claims: CLAIMS 1. Method for growing fungi, in particular edible toadstools, comprising the steps of: a) arranging a nutrient layer in a growing space, b) arranging mycelium in the nutrient layer, c) cultivating the mycelium to fungi, and d) harvesting the fungi, characterized in that the nutrient layer arranged in the growing space is substantially compost-free. 2. Method as claimed in claim 1, characterized in that the nutrient layer is formed by arranging on a relatively thin compost layer a moisture-absorbing layer whereof the thickness amounts to at least half the thickness of the compost layer. 3. Method as claimed in claim 2 , characterized in that the thickness of the moisture-absorbing layer is at least equal to the thickness of the compost layer. 4. Method as claimed in claim 2 or 3 , characterized in that the thickness of the moisture- absorbing layer amounts to at least double the thickness of the compost layer. 5. Method as claimed in any of the foregoing claims, characterized by the step of: e) disinfecting or replacing the nutrient layer and subsequently repeating steps b) to d) . 6. Method as claimed in any of the foregoing claims, characterized in that the nutrient layer is arranged on a displaceable carrier. 7. Method as claimed in claim 6, characterized in that the mycelium is arranged in the nutrient layer outside the growing space and the carrier is then moved into the growing space . 8. Method as claimed in claim 6 or 7 , characterized in that after step c) the carrier is moved out of the growing space and harvesting is carried out outside the growing space. 9. Method as claimed in any of the foregoing claims, characterized in that the growing space is substantially kept free of pesticides during steps a) to d) . 10. Apparatus for growing fungi, in particular edible toadstools, comprising a frame for placing in a growing space which is provided with a number of substantially horizontal carriers for a nutrient layer placed one above another, characterized in that the carriers are arranged in the frame with an interspace in vertical direction, and the interspace is smaller than 40 cm, and preferably smaller than 30 cm. 11. Apparatus as claimed in claim-10 r characterized in that the interspace is smaller than 20 cm and preferably amounts to about 15 cm. 12. Apparatus as claimed in claim 10 or 11, characterized in that the carriers are arranged movably in the frame. 13. Apparatus as claimed in claim 12 , characterized in that the carriers comprise conveyor belts movable through the frame. 14. Apparatus as claimed in claim 13 , characterized in that the carriers comprise strips of cloth slidable through the frame.

Inventors: OOSTVOGELS JOHANNES PETRUS COR, OOSTVOGELS, JOHANNES, PETRUS, CORNELIS
Applicants: OOSTVOGELS JOHANNES P C, OOSTVOGELS, JOHANNES, PETRUS, CORNELIS
Application year: 1997
Main classification: A01G1
IPC codes: A01G1