Artificial meteorochory

Fungal hyphae grow on surfaces in hairy filamentous structures. These should grow around plant seeds which could not fly by nature and thus enable them to be spread by the wind. Examples are hair- or paragliders like taraxacum seeds.
For this purpose, the plant seeds are coated with a thin layer of substrate, which serves as food for the fungus to form appropriate structures.
The resulting mutualistic flying objects can be used for continuous, autonomous seeding of endangered plant species or contribute to the fertility of wastelands through the soil-opening combination of certain fungal and plant species.

video of Eric’s project
Eric Geißler
project:mutual affairs

full concept text

Usually the hyphae follow nutrition gradients in the soil but when they reach the surface they can also grow above the ground in fluffy mycelium structures in order to find new nutrition sources. The phenomena about this is that they spread the weight of what they eat into those hairy structures and thus produce layers of lightweight construction.

The length of the hyphae and so the fluffiness of the mycelium depends on various factors. Most significant seems to be the type of the mushroom and the atmosphere around it. In comparison to conventional breathing air the above ground mycelium grows bigger when the concentration of oxygen in the atmosphere is slightly less and the amount of carbon dioxide is higher (see: Ross,P.(2019). Mycelium growth bed (11032982). United States Patent Application).

For my experiments I chose the mushroom Schizophyllum commune with the most luscious mycelium in the BioLab. I wrapped fennel seeds with a very thin layer of substrate made from malt extract and inoculate it with fungi liquid culture. Then I pined them up on needles in order to enable growth in most possible directions and put them in a closed box with distilled water to provide high humidity. The best growth results happened in the incubator at 29°C.

Up to two weeks of growth, the mushroom is fed just by the nutrition of the substrate layer until it starts to assimilate the outer layers of the fennel seed. It’s fascinating how big and fluffy the mycelium gets within that time. The result is a short living parachute for the seed.

Threatened plant species could benefit from the autonomous and continuous dispersal of their seeds by the wind. Nature can be quite hostile to life also during the optimal seeding period, depending on the weather conditions. A permanent flow of seeds increases the chance for an organism to sprout in it’s individual best fitting conditions. Furthermore the mycelium could help the seedling as a protective coat or, when dying as a fertile soil. When we think of mycorrhiza mushrooms as partner for the seedling, even a mutualistic relationship between the plant and the mushroom is thinkable. Another use case could be the fertilization of wasteland like desertificated areas, salinated lands or brownfields. Therefore the soil building effect of both organisms could be helpful: While mushrooms could open up minerals, plants could mechanically open the ground with their roots. Former mining wastelands got soil without hummus, which is heavily agitated and compacted or even contaminated. In this case small-grained legumes bind the nitrogen from the air and thus make the soil sustainably fertile when they rot again. Some mushrooms are able to do break down stubborn chemicals (mykoremediation).

Different breeding concepts for the mycelium parachute could be thinkable: One concept is the “SeedGun”, which breeds the parachutes around the seeds and set them in the flow of the wind totally autonomously. While the mycelium is growing bigger in a constant airflow, the object is rising in the cylindric tube until it’s got soaked out of the device when the wind is right. The streamlined outlet is rotatable and follows the direction of the wind. The device could be set up as a fleet in barren areas, reminiscent of wind turbine farms. Another option is to grow the flying objects on PTFE or mesh mats, harvest them afterwards and sow them by a drone using the broad spreading effect of the parachutes: A few flights over a big area should be enough rather than sow every seed with a gunshot, as is done by drones seeding treeseeds.

Or imagine a snow canon like machine is blasting the objects much further than seeds without the mycelium parachute. For intercropping periods between profitable harvests such a cannon, packed on a trailer, could seed an entire field with clover which would take maybe just one than 20 tractor trips.