Mycorrhizal fungi

Do we need this?
How did we manage without it?
Has Monty Don got shares in it?

 

Yep it is the modern fad.
Having said that there might well be something in it, as the principle seems right.

But I did read there are loads of fungi,mostly specific to each plant, that are beneficial.

 

My understanding is that the fungi helps the roots take nutritions from the soil. It will get there naturally. So you don't 'need' to provide it. But if you do, the roots can start taking nutritions earlier.

I could be wrong though..

 

We don't: plants do
Mycorrhizal fungi can be lost from the soil by over cultivation and fertilisers. So providing some from a packet gives the plant a head start as natural colonisation can be slow due to a scarcity of the fungi.
A while ago I found this site Mycorrhizal Associations: Introduction

 

I've never seen any solid evidence that these products are beneficial for gardeners. There are lots of anecdotal claims about how great they are, but no hard evidence. There's no doubt about the importance of mycorrhizas, but the claims made by the manufacturers of these products aren't backed up by any actual published data.

You'd have to severely abuse your soil to eliminate the naturally occuring mycorrhizal fungi. Inoculation might well be helpful in some circumstances e.g. plants grown in soil-less composts, but you could probably achieve similar results by adding in a % of garden soil to the mix.

 

I am going to do a side-by-side test with my tom and pepper plants this year. I plan to apply the fungi to half of the plants, then grow them in the same bed. Will report the result here - unless I forget.

 

Good idea. Greenhouse tomatoes is a case where mycorrhizal inoculation might potentially be beneficial, since the species is highly mycorrhizal and levels of the fungi in the greenhouse soil could potentially be low depending on the conditions (even more so using soil-less compost). Would also be interesting to try inoculating some plants with a small quantity of topsoil/roots from e.g. an unfertilised lawn with plants like daisy, clover or plantain which are all good host species.

 

Trees use it as their internet. When a pest attacks one tree it sends a chemical message via the fungus to warn the other trees, they then produce chemicals in their leaves that makes them unpallatable to the pests

 

Mycorrhizal fungi are more important to some plants than others. Orchids and heathers are a couple that spring to mind.
@blacktulip I would do the trial in two separate beds/containers rather than on half the plants in one bed as how can you guarantee that the mycorrhizal fungi will not spread to the untreated plants if in the same bed.

 

It's hard to get round this problem if you're growing in beds. E.g. if you have 2 beds and you inoculate plants in one but not the other, you essentially only have 1 independent replicate (each bed, not each individual plant). This makes a statistical comparison impossible. For instance, one bed might have more fertile soil or get more sun than the other.

Growing in pots avoids that problem, but you need to take care to randomise the design at all stages i.e. don't put all your strongest seedlings into one group, and don't group all the pots of each treatment together where one group might get more sun or be better watered.