About Mycorrhizal Fungi

Mycorrhizae are promoted as friendly fungi and when introduced onto the feeder roots of plants they develop on the roots and act to extend the natural root of the plant.  A natural relationship is then formed between the plant and the fungus, this is called a symbiotic relationship.

I have been inoculating all my Fuchsias with Mycorrhizae and I am very pleased with the results.  If, like me watering and feeding can sometimes be a bit hap-hazard, by installing this natural pipeline between the soil and the plant, it will help compensate for margins of human error.  The result is generally better, healthier plants.

In effect what Mycorrhizae does is it reduces drought stress, reduces water and fertiliser needs, reduces disease losses, reduces transplant shock, increases plant quality and yields, increases resistance to soil born diseases, promotes extensive root system, promotes soil structure and reduces insecticide dependency, all good things.
What follows is a very brief overview of Mycorrhizae with links to more detailed resources at the bottom of the page.

The term mycorrhiza, literally means fungus-root.  It refers to an association or symbiosis between plants and fungi that colonise the cortical tissue of roots during periods of active plant growth.  The association is characterised by the movement of plant-produced carbon to the fungus and fungal-acquired nutrients to the plant. It is a bi-directional movement of nutrients where carbon flows to the fungus and inorganic nutrients move to the plant, thereby providing a critical linkage between the plant root and soil.  In infertile, nutrient-poor or moisture-deficient soils, nutrients taken up by the mycorrhizal fungi can lead to improved plant growth and reproduction.  As a result, mycorrhizal plants are often more competitive and better able to tolerate environmental stresses than are non-mycorrhizal plants.

The benefits afforded plants from mycorrhizal symbioses can be characterised either by increased growth and yield or by improved fitness (i.e., reproductive ability).  In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil.  Mycorrhizal fungi usually proliferate both in the root and in the soil.  The soilborne or extramatrical hyphae take up nutrients from the soil solution and transport them to the root.  By this mechanism, mycorrhizae increase the effective absorptive surface area of the plant.

There are several types of associations in form and function and many specific to a particular species, an estimated 95% of all plant species belong to genera that characteristically form mycorrhizae.  The mycorrhizal condition is the rule among plants, not the exception.  Fuchsias form relationships with Endomycorrhizae also known as Arbuscular Mycorrhizae which belong to the order Glomales and form highly branched structures called arbuscules within root cortical cells.

In simple terms what the fungus does is form a sheath-like structure at the root tips of the host plant through which it passes to the plant various nutrients it has gathered from the soil in exchange for food the plant has produced through photosynthesis.  It can be considered a highly effective transport system, like a pipeline, between the soil and the plant, moving water and nutrients to the plant in exchange for direct access to the carbon-rich products of photosynthesis.  This becomes a mutual relationship for the benefit of both the host and the fungus.  Whilst the plant will survive without the fungus the fungus needs to ensure the plant survives or the fungus itself will not survive.  The obvious benefit to the plant is that the fungus ensures the plant is maintained in the best way possible to optimise its health.

When we grow our Fuchsias in pots, I would say the majority of us use a sterilised growing media.  This implies any beneficial bacteria or fungi as well as parasitical entities are destroyed to give us a safe, clean and essentially unnatural media to grow our plants, not a living soil as one would expect in any natural habitat. By inoculating with Mycorrhizae you are effectively putting some of the natural components back into the soil.

Listed below are some links to additional resources :-

Mycorrhizal Associations Web Resource

Mycorrhizal Applications Inc

What the RHS say about Rootgrow

For further information watch this Rootgrow video