MYCORRHIZA IS

               A GARDENER'S BEST FRIEND

A mycorrhizal fungus is a special type of soil fungus that grows only on or inside plant roots; but it does not cause disease or harm the host plant.

This kind of relationship is described as a symbiotic  relationship. The host plant and the fungus mutually benefit from their close association with each other.This relationship is so special that even if spores of this fungus are in the soil, they will not germinate or grow if the right type of plant species is not growing there.

       How do you know if you have this fungus

                       in your garden soil?

 If your garden is doing well, even without the addition of synthetic fertilizers, you probably have a healthy colony of these beneficial fungi thriving in your soil.

You can only see them by examining the roots with a microscope. You will see masses of white strands along the root tips; or you may also see small, dark, round spore structures within the root tip cells.
 

                        What are the types of mycorrhiza?
 

The two major groups that occur widely are the ectomycorrhiza (ecto- meaning outside) and endomycorrhiza ( endo meaning inside ) fungi. Ectomycorrhiza grow on root surfaces and are associated with the roots many different kinds of forest trees. We see their fruiting bodies as mushroom caps, puff balls and morels. Truffles are underground fruiting bodies of the same large group of mycorrhiza. Not all mushroom caps we see in our garden are mycorrhizal; some are saprophytes, growing on decaying wood or vegetation buried beneath the soil surface.

The second large group, the endomycorrhiza fungi, typically
invade and grow inside the root cells. Here is a delicate, harmonious relationship between the plant and the fungus. This union is so perfectly balanced that the plant does not become ill from this fungal invasion.

A special character of this fungi group is the requirement for very special unknown growth factors. So far no one has succeeded in culturing this fungus in the laboratory on artificially created growth media. 

They do not produce mushroom caps. Spores are produced
in the soil or within the host tissues. In nature, they are found
growing with a wide variety of different species of herbaceous plants such as grasses, flowers and vegetables.

                       How does the fungus benefit?
 

Mycorrhizal fungi cannot make their own sugars required for
 
living. They are fully dependent on the plant for food.
     

                How does the plant benefit from this?
 

Even though the soil may be rich in phosphorus, it is

insoluble and immobile. The fungus transforms phosphorus

to a form that the plant can use.
 

Other benefits to the host plant include:

making micronutrients available,

protect the roots against absorption of toxic heavy metals,

protect the host plant roots against several soil-borne diseases,

protects the plant against drought. Fungal growth on the root tips extends absorbing root surface area.

The health and survival of many trees and shrubs have been documented to be fully dependent on the presence of these important fungi. Many trees and shrubs will not grow, or survive without this special kind of mycorrhiza fungi that they need.

Experiments have shown that when native trees were planted  into other non-native locations, they grew poorly and eventually died. This happened even with applied  fertilizers.

But when native soil from where these trees were originally grown, were mixed into the transplanted soil, surprisingly significant differences were noted in tree growth and survival, when compared to those trees planted without native soil treatment. Those trees that received transplanted original soil grew faster, taller and more vigorous.

The conclusion from these experiments indicated that native soil contained the special type of mycorrhiza fungus that the tree needs to grow, and that this special requirement cannot be replaced by the addition of chemical fertilizers.

 
    
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