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What do you think about mycorrhizae fungi?

Posted by leaveswave (My Page) on
Tue, Nov 2, 04 at 7:16

As a commercial product, I mean. Can it really help plants grow better/faster or is the stuff dead/inactive by the time it gets back into the soil?


Follow-Up Postings:

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RE: What do you think about mycorrhizae fungi?

I don't know ... I have Fungi growing in many of my beds and I don't remember anyone putting it there .. ??

Good Day ...


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RE: What do you think about mycorrhizae fungi?

It is estimated that only about 12% of plants do not have mycorrhizae. Many of them are in the mustard family. Chances are that the fungi needed for mycorrhization are already present in your soil. There is evidence that excess nitrogen in the soil can reduce mycorrhizal development. I suppose one question would be, why do you feel that you need to add a fungus for mycorrhizae to develop?


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RE: What do you think about mycorrhizae fungi?

lyc..., didn't say I felt any such need. Please be careful about the assumptions you make.


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RE: What do you think about mycorrhizae fungi?

Just received from my Master Gardener network:

Mycorrhizae--the Friendly Fungi
Rhoda Burrows, Graduate Research Assistant, Dept. of Plant Pathology
U of MN Extension Service

When you hear "fungi", what comes to mind? Mushrooms and toadstools, or mold and mildew? Or plant diseases such as Dutch elm and late blight? Did you know that most plants have beneficial fungi in their roots? These fungi extend from the roots into the soil, and help supply the plants with nutrients such as phosphorous and nitrogen, in exchange for carbohydrates from the plants. This mutually beneficial relationship is known as a mycorrhiza, which translated literally means 'fungus-root.'

There are several different kinds of mycorrhizae, depending on the plant host. Most trees and shrubs in Minnesota form "ectomycorrhizae" (ecto- = "outer"), in which the fungi build a sheath around the roots, and penetrate between but not into the root cells. Since most ectomycorrhizal fungi form mushrooms as their means of reproduction, you have probably seen many of these fungi when walking through a forest after a rainy period. Many trees and shrubs need these fungi in order to thrive, or even to survive.

Orchids, including natives such as the Showy Lady's Slippers, are dependent on their mycorrhizal fungi for early growth because their tiny seeds don't contain food reserves for the newly-germinated plant. Unlike other mycorrhizaes, the orchids don't supply these fungi with carbohydrates - instead, the fungi supply the orchids with energy as well as nutrients obtained from decaying organic matter. In fact, it's unclear whether the fungi receive anything at all from the plants in return for their contributions.

Most Ericaceous plants, such as blueberries, cranberries, and Rhododendron, form "ericoid" mycorrhizae, where the fungi grow into the cells of the root epidermis (the outer tissues of the root).

And finally, 80% of plants form a type of mycorrhizae known as "endomycorrhizae" (endo-="inner"), in which the fungal hyphae do enter inner root cells, altering them to form "arbuscules", which are specialized nutrient exchange surfaces. It is from these structures that these fungi get their name "Arbuscular mycorrhizal fungi", or "AMF". Grasses, wildflowers, and most garden plants (except those in the cabbage family) form this type of mycorrhizae. Fossil evidence indicates that AMF were present when plants first colonized land, which may help explain why they are so common. Many tallgrass prairie species, including big and little bluestem grasses and wildflowers such as butterfly weed, would probably not survive without these minute partners in their roots.

There are a number of commercial companies that will sell inoculum to the concerned homeowner for their plants. Will it help? That depends. If you are planting trees in an area where there are none, inoculation with the appropriate ectomycorrhizae may be of benefit. If you are trying to germinate orchid seed, their fungal partners will need to be supplied. Ericaceous plants may benefit as well. However, few field studies have shown benefit from spreading AMF inoculum on your yard or garden, perhaps because these fungi tend to be fairly common and are likely to be present already. Also, if you fertilize heavily with phosphorous, or use certain soil fungicides, you are unlikely to see much benefit from applying AMF, because their effects will be masked, or they will not do well. However, if you start your own seedlings in a sterile or artificial soil, inoculating them may help them survive transplanting and increase their resistance against soil-borne disease.

Yard & Garden Line News
October 1, 1999


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RE: What do you think about mycorrhizae fungi?

May be the motherlode website on this topic!

neat stuff

Very detailed, very interesting, and lot of pictures.


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RE: What do you think about mycorrhizae fungi?

Leaveswave, I was not making an assumption. My question was related to the proposed application. I am not sure why I would need to be careful though. Were you interested in a discussion or simply looking for a yes/no answer? If so, than the answer is yes.


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RE: What do you think about mycorrhizae fungi?

my first guess is yes, might as well add it. cant hurt.

but then im sitting here thinking...(which is usually a scary process)

lets pretend that ur putting in a native plant that has evolved with the fungi. certainly specific plants have specific fungi. so we put in our pretend tree with the commercial bought generic fungi added. i could imagine that they have like 3-5 spp of fungi in these packages but certainly not running that gambit of what said pretend plant needs for spp. i could imagine that innoculation of pretend plant could inhibut natural fungi for a short amount of time. i would also imagine that native fungi will prob always win out thru time. and eventually the fungi and plant meet and start a family. so the question is, does it help to have that fungi around from the start? i dont know the answer and im sure its plant AND fungi spp specific answer. im sure some will more than gladly accept it whilst others react badly.

moral of the story is that people have been re-planting plants without fungi for, well, forever.
so i say forgo the fungi and spend the $$$ on something useful, like less mow grass and more veggies in ur front yard.

froggy


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RE: What do you think about mycorrhizae fungi?

I think maybe you can compare the use of mycorrhizae inocculants to that of compost starters (to some extend)

If you are trying to compost, compost starters can sometime provide faster result especially if the microbes responsible for breaking down organic matter is not abundantly available in the raw materials. However, in far the most cases, the microbes are available naturally in sufficient qualitities to ensure that compost starters are not necerssary. All you may benefit from the inocculants is a temporary head start, if even that. As mentioned in the above articles: only soils which are deficient in the mycorrhizae will benefit. It is like saying: only soils which are deficient in fertilizer will show a benefit from having more fertilizer added (goes without saying, no ??)

This is one of these cases where the value of mycorrhizae has been documented (just as the value of microbes for composting has been documented) but the real value of having inocculants added seperately may be questionable because the fungi is usually already present and can multiply as needed.

Another issue which I have not touched on yet is the discussion of fertilizer (phosphorus) on the mycorrhizae. It has been proven that excessive amounts of phosphorus (soils high or very high in phosphorus) tend to show lower levels of mycorrhizae. This has been interpreted by some to mean that the addition of phosphorus to soils will make plants "dependent" on the fertilizer (e.g. before plants took up nutrients effectively aided by mycorrhizae but now after being fertilzed with phosphorus the mycorrhizae dies and uptake of nutrients are now reduced requiring even more fertilizer to be added. In effect hurting the plants by high phosphorus fertilization).

The explanation certainly sounds reasonable ? I am not sure, however, that this cause/effect is necerssarily correct or atleast so clear cut as presented. Maybe this has to do with plants not needing the mychorrhizae and the symbiotic relationship no longer is present ? (e.g. high phosphorus being a sign of high fertility in the soil in general). Does this means that mycorrhizae disappears not to return when phosphorus levels are reduced ? or what ? It atleast should make you reconsider the application of superphospate for example as recommended in many garden books. But on the other hand, it could be interesting to learn that when the studies site high phosphorus = low mycorrhizae what other factors were present ? which type of fertilizer used to bring about the high phosphorus reading ? What was the other nutrients at that time ? could it relate to high fertility = low need for mycorrhizae by the plants (if nolonger a symbiotic relationship, why would mycorrhizae be needed). The fact that mycorrhizae and root noodles infected with the fungi is reduced under high phosphorus conditions is that cause by the phosphorus affecting the mycorrhizae ? or by the plants affecting the mycorrhizae due to limited need under high fertility conditions ?

My personal opinion is that the use of mycorrhizae additions is probably overrated partly because this fungi is already present where it needs to be and sometimes the plants it is being applied to may not enjoy the same symbiotic relationships as the test plants used for documentation purposes (e.g. some trees depend significantly more on the fungi compared to most perennials for example). It depends largely on the root structure, soil fertility, and the growing conditions.

Another opinion of mine is that having to buy mycorrhizae fungi inocculants is not worth the money is used outdoors, but if added to, say, an indoor bonzai plant it may prove more useful. Then again, if you grow indoors, you can control lots of things with an occational feeding with some fertilizer, and the benefits again comes into play.

Just a few thoughts.


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RE: What do you think about mycorrhizae fungi?

An organic method: if you are planting native trees similar to the trees that surround your planting area (say you are planting in a soil degraded area clearcut for a housing development), take some soil from a nearby treed area and mix it with the degraded soil, thereby innoculating the soil
with native mycorrhizae.


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RE: What do you think about mycorrhizae fungi?

That works for compost too. Toss some soil in between the layers when you start a new pile.


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RE: What do you think about mycorrhizae fungi?

A few additional thoughts in answer to your question. In general it is not necessary for the home gardener to add commercial MF (mycorrizae fungus)to plantings, especially if planting something in the same family common to your area. However, if you are starting a new strawberry bed or grape arbor MF has proven to be a excellent addition to the soil.

Leaveswave has posted an excellent, but scientific site on the the subject. Let's simplify it a bit for better understanding on the subject. In the natural, undisturbed plant world plants grow, die, shed leaves and litter. This, in turn, COLD composts on the ground year by year and encourages the development of MF. As you know, tree feeder roots lie just under the surface of the soil where they can find a ready supply of MF in the forest floor.

MF will develop in a finished compost pile if the pile is spread out a bit and allowed to remain untouched for a year or more. I "grow" my own MF. It is easy. Under an out of the way, shady shrub grouping I secured a piece of landscape cloth about 6' long on the ground. On top of this I shoveled an inch deep layer of finished compost and then added a 4" layer of shredded leaves from trees and plants. The whole pile is about 5" high replicating nature's method. This cold composts over the winter and when I am planting shrubs/trees in the spring I top each planting hole with a small shovelful of this. The pile is replenished every fall with shredded yard leaves. It is an on going process. Bonsai growers will find this method of developing specific types of MF very helpful if they add all their clippings from bonsai trees to this type of cold composting pile.

However, the commercial forms of MF do have their place and can be very helpful. Oak trees respond well to a treatment of MF plus fertilizer injected by a qualified arborist around their outer roots. Ditto other types of trees which might be showing signs of stress. It is very common for a heavily wooded lot to be purchased, cleared of all but a few significant trees, built upon and lawns planted. Suddenly, elderly trees have been robbed of their source of MF as tidy homeowners rake and removed the annual leaf drop. The trees begin to decline, robbed of MF. This is the type of situation where I would encourage a MF treatment. Not inexpensive...but not as expensive as having a tree removed.

Those of you who rake and shred your leaves every fall then spread them back under shrubs, trees and on garden beds as mulch are encouraging the growth of healthy MF which means healthy plantings. It's as simple as that.


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RE: What do you think about mycorrhizae fungi?

Thanks Nandina, Just shows again how important organic matter is for healthy soil.


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RE: What do you think about mycorrhizae fungi?

Nandina's comments are interesting. Here are some additional thoughts. A colleague of mine was researching mycorrhizal fungi a few years ago. When soil minerals and moisture were ample, he found that the mycorrhizal associations were not made with the plants even when the fungi were present. He found that mycorrhizal inoculants were very useful when transplanting nursery plants grown in a sterile medium into poor soil low in organics where the plants did not receive follow-up fertilization and irrigation. In particular, this was useful when transplanting native plants into restoration projects.


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RE: What do you think about mycorrhizae fungi?

If you live anywhere near a city, then chances are that your soil has been depleted of Mycorrhizal Fungi. If you have ever seen a house being built then you know what happens to the top soil. In today's landscape environments, many of which are created from large earth moving projects designed to accommodate park-like office complexes, high density housing, factory buildings, suburban housing developments, large landscape projects, urban construction, highway construction, municipal settings and many others, the soils are virtually void of essential mycorrhizal fungi and are generally lacking in essential mineral elements. In order, to successfully establish plantings of any kind, from large trees to small shrubs, beneficial mycorrhizal fungi must be present.
When you add mycorrhizal fungi during transplanting, the plants:
Have improved water and mineral element uptake and assimilation.
Have better transplant survival and growth rates.
Have improved heat and drought tolerance.
Have better resistance to root disease.
Have better root and shoot growth rates after planting.
Survive better in poor soils.

Adding or attempting to grow mycor in compost will not work. It is too hot. You can obtain your own from the forest, if you would like to dig it up yourself.
If you plan on purchasing it, make sure that you are getting spores and not "probagules," or "viable organisms." Separating the Endo spores is a very difficult task, so most companies will not make the extra effort. Also, Ecto spores can be watered through the soil, Endo spores are too big and must be applied during planting.
The most innovative company (and the ONLY one with endo spores) is Plant Health Care, Inc. They have a website if anyone would like more info: www.planthealthcare.com I welcome all responses.


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RE: What do you think about mycorrhizae fungi?

"If you live anywhere near a city, then chances are that your soil has been depleted of Mycorrhizal Fungi."

If you live anywhere in the US, chances are that your soil has been depleted of mycorrhizal fungi to some extent! At the very least you can assume that the species composition of your soil has changed fairly drastically.

This tends to be most important for growing native species. Most plants that are commonly cultivated are non-mycorrhizal or just not too picky about the species they grow with. Many natives, on the other hand, have species-specific plant/fungal interactions. Not only are the plants often not going to do well without the right fungi, the fungi often aren't going to do well without the right plants; as a result, many of these fungi will have disappeared from areas that have been drastically disturbed, a category into which most of the US falls. This has led to failure of many a restoration project, and is probably a major factor in the fact that, while some natives are very easy to cultivate, others that can be very prolific in the wild never seem to do well in cultivation. So the gist is, commercial mycorrhizal inoculants are going to be useful to the extent that:
1--your soil is lacking in the right mycorrhizal species for the plants you're trying to grow, and
2--the inoculant contains those mycorrhizal species.
Both of those, of course, depend entirely on what inoculant you're using, what's already in your soil, and what plants you're trying to grow. This makes generalizations virtually impossible.

Patrick Alexander


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RE: What do you think about mycorrhizae fungi?

There are 4 main species of Vesicular-arbuscular Mycorrhizal fungi that colonize the roots of ALL garden flowers, perennials, and plants commonly used in landscape plantings. They are Endo mycor:
Entrophospora Columbiana
Glomus Etunicatum
Glomus clarum
Glomus Intraradices
It doesn't matter Whether you are planting native or non-native species of plants. These mycor species are world-wide.
Mycorrhizal fungi can not grow unless it has a plant to attach itself too. It forms a symbiotic relationship with the plants and cannot be grown on its own.
Pisolithus Tinctorius is the main Ecto Mycorrhizal fungi species that colonizes with almost all tree and shrub species.
Rhododendrons, azaleas, and mountain laurels are picky about their mycorrhizal associations.


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RE: What do you think about mycorrhizae fungi?

"There are 4 main species of Vesicular-arbuscular Mycorrhizal fungi that colonize the roots of ALL garden flowers, perennials, and plants commonly used in landscape plantings. They are Endo mycor:
Entrophospora Columbiana
Glomus Etunicatum
Glomus clarum
Glomus Intraradices
It doesn't matter Whether you are planting native or non-native species of plants. These mycor species are world-wide."

What's your source of this information? I think this was essentially the accepted view earlier, but has since been discredited by more recent research. One of the major reasons for this is that earlier VAM fungal taxonomy tended to be very conservative, lumping large numbers of disparate taxa into a few highly polymorophic and artificial species. Another reason is that simply whether or not a given VAM species will form a mycorrhizal relationship with a given plant species in pure culture turns out not to be a very meaningful indication of whether or not that VAM fungi will form mycorrhizal relationships with that plant in an actual community or of whether that plant is actually getting any significant benefit from that VAM fungus.

Patrick Alexander


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RE: What do you think about mycorrhizae fungi?

My info comes from my own trials, and a biologist named Dr. Kernan. You are more than welcome to contact him- mkernan@planthealthcare.com.

What recent research has discredited VAM? I would love to see that!


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RE: What do you think about mycorrhizae fungi?

I have had some benefit from inoculating seeds and seedlings with a commercial mycorrhizae when I grew them in a sterile potting soil. I used to have a native plant perennials nursery in northern Arizona. I started using MF as an experiment and kept records of which species had noticably larger root systems and which had larger top growth. At the age of plants I was working with, I found that most had improved root systems (more branching, more length) when treated with MF. Very few showed any improved top growth. Some species did not respond at all. I did find that a few species I had that often grew poorly and had weak root systems, did much better with the MF. This included Asclepias tuberosa and Lupinus sericeus. I also was able to grow Castilleja integra only after using MF. Granted suitable species of these fungi likely were present in the native soil where they eventually were planted, I do believe many benefited from the inoculation while they were in the nursery.


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RE: What do you think about mycorrhizae fungi?

"What recent research has discredited VAM? I would love to see that!"

Discredited VAM? I was referring to work that has indicated both a much greater level of diversity within VAM fungi and a much greater degree of host-specificity than was previously thought to exist; this makes VAM more important in many ways than previously thought, rather than in any way discrediting them. The work I'm familiar with is by Dr. J.D. Bever, at Indiana University. He seems to be the main one doing work on the role of VAM in community structure &c. I worked for him for a couple of years. It's the view that VAM diversity is essentially irrelevant that no longer seems tenable.

Anyways, another thing occurs to me that's worth mentioning--in cultivated plants, there's a strong bias towards non-mycorrhizal or very non-specifically mycorrhizal species, for the simple reason that plants with high mycorrhizal specificity can be extremely difficult to cultivate (although once you know that the VAM are the limiting step, inoculation can generally circumvent these difficulties). So within the realm of the commonly cultivated plants, it might well be true that using a small number of VAM species will get you by just fine. OTOH, VAM diversity is definitely important in maintenance and structuring of native plant communities, and the implication that VAM diversity can be safely ignored--whether we're talking native plants or not--is the main thing I was reacting to in your earlier post.

Patrick Alexander


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RE: What do you think about mycorrhizae fungi?

...utilizing leaveswave's link to the Mycorrhiza Information Exchange site, I might suggest a few key words utilizing their search engine:
"disturbance";"phosphorus"; "VAM isotypes";"Legume propagules + tilling"; "water pollution"


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RE: What do you think about mycorrhizae fungi?

  • Posted by SoCal23 USDA10/Sunset23 (My Page) on
    Sat, Nov 12, 05 at 12:52

Just one observation about phosphorus and its impact on mycorrhizal associations. Phosphorus binds very tightly to soil colloids; in an undisturbed environment there are normally only two ways for a plant to obtain phosphorus: 1.) Periodic application of a phosphorus that can be temporarily held in an available form or 2.) mycorrhizal symbiosis, as fungal mycelia are quite adept at direct mining of phosphorus (and practiced by non-symbiotic soil fungi which is one of the reasons why ruderals like disturbed soil). Direct interception accounts for a very small amount of a plant's needs with the exception of Proteaceae (which incidentally, are completely non-mycorrhizal).

Ryan


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RE: What do you think about mycorrhizae fungi?

I suggest that the sustainabilty of population densities throughout tenuous stages of of reproductve development may not be dependent on exceeding threshold limits of one chemical input.
"Ball in your court..."


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RE: What do you think about mycorrhizae fungi?

Another good link...

Here is a link that might be useful: Mycorrhizal Management


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RE: What do you think about mycorrhizae fungi?

Rose;Patrick Alexander is correct.H.Marschner;2nd.edition, (chapter 15:The Soil-Root Interface(Rhizosphere) in Relation to Mineral Nutrition>>15.11 Mycorrhizas:Practical Implications, suggests a series of limitations. If one interfaces this book with journal sites where other considerations are further elucidated,I might be more interested in intercropping with legumes...


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RE: What do you think about mycorrhizae fungi?

i would like to do an experiment in connection with mycorrhiza and (hopepully) African trees used in agro-forestry. So far i have considered to use Prunus africana; i am going to go to Africa for some months, but thinking to do the experiment (e.g. propagation .. ) when i'm back. at the moment i have no motivation for this project; has anyone ideas to make it more relevant/ useful/ interesting ? it would be better to do it in Africa, but i may have no time or facilities there.

Grace


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RE: What do you think about mycorrhizae fungi?

A new book 2010 --Tiber Press showed up in my local library:
TEAMING WITH MICROBES ---The Organic Gardener's Guide to the Soil Food Web. The hype on the cover stated ""A breakthrough book for the field of organic gardenening--AMERICAN GARDENER" I was skeptical but American Gardener is no slouch magazine. I was not disappointed. The book goes through all the aspects of bacteria and fungi (including various mycorrs) So my garden project list is to build an 'aquarium bubbler' to aerobically oxygenate a wad of finished compost and 'brew' some compost tea--unlike like my previous compost teas which I let set in a barrel and become anaerobic. There is a message here worth exploring. PII


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RE: What do you think about mycorrhizae fungi?

petiole2 yours is the second recommendation I have seen regards 'Teaming with Microbes' in the space of a few weeks. I really must try to secure a copy for my perusal as I am very interested especially in bacteria's role in nutrient cycling and how to culture beneficial microherd including fungi.


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RE: What do you think about mycorrhizae fungi?

A botanist I am not - but I think I can contribute an observation finally arrived at in my own garden. I have a prize spot in my backyard (prized because it gets all day sun, is in full view from my kitchen window) that gave me headaches for almost 12 years because nothing I planted there would grow, let alone thrive. I tried every tree, shrub, bush, bulb and what have you in that spot and everything died. Like clockwork, dig and prep hole, mix new soil with existing soil and gentle fertilizer, plant plant, firm soil, water attentively for about two weeks and there they went - a succession of roses, citrus trees, gardenia bushes, etc. All dead after two weeks. And no, there was nothing different about that spot from a spot just three feet further on either side, no tree, plant structure or anything had been there so I ruled out all possible factors I could think of, nothing ever was happy there. Ultimately I put a compost bin there, been there ever since and whatever I plant right next to it now grows gangbusters so it's become the spot to either "rescue" marginal plants or grow on specimens for transplant after a few months. I have noticed that every plant, once there for a while and then dug for final planting has many, many webby roots and rootlets, just masses of them just under the surface of the mulch layer. Few other plants in my yard have them unless they first were in the "recovery" spot next to the compost bin. Any connection there? I think yes. I for one am sold on composting and using it to colonize all of the soil in my garden - little by little. Btw, I love lurking in here.


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RE: What do you think about mycorrhizae fungi?

The Micros in question will not survive without plants association. They will not thrive under stressfull cultural practice. If you are planting in a sterile medium, on land that has been left fallow for more than 6 months, or want to grow a prize winning petunia or tomato than it would be benifficial to add the fungus. The fungus can move only about 30cm/year in the soil, so it may take a long time to repopulate a large area of once fallow ground by colonizing from the edge. When planting an ornamental grass in sod, there would probably already be compatable micros present, or an evergreen in a boreal forest, for example. If planting an evergreen tree in a wheat field, add some ecto micros. use common sense.

But definatly if you wish to grow a prize winning plant say for competition, exhibition, or want to get 20% more peppers from your vegetable garden, have limited ability to nurture a plant, expect drought, tough or adverse conditions, use supplemental micros to better your plant's chnces of survival.


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RE: What do you think about mycorrhizae fungi?

They grow Mycorrhizae in vitro with new technology that provides:
Pathogen free bioreactors(in laboratories with negative air pressure) guaranteed spore counts and viability for consistent homogenous ecto and endo spores.
Largest mfg-supplier with awesome results.
www.usemykepro.com harc@premiertech.com

Here is a link that might be useful: Premiertech web site


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RE: What do you think about mycorrhizae fungi?

All organically-produced endomycorrhizal fungi (AMF) are currently cultured in a granular format. The only invitro-produced mycorrhizae are lab cultured in petri-dishes utilizing genetically modified carrot roots (no carrot attached). Since there are no fruiting bodies (carrots) all the carbohydrates exuded by the root stock go into fueling the mycorrhizae. You gain the advantage of high-spore counts, but loose the "conditioning" the spores gain from being grown in their natural environment. These GMO mycorrhizal species are produced in several locations world-wide, the most notable being India.

Invitro spores look identical under microscopy (like clones) and contain no fatty cells (the fuel source which allows mycorrhizae to sporulate). The resulting spores have a very low rate of success and often do not survive under real world conditions.

It is also of great importance that a mycorrhizal inoculum contains a vast amount of inner-species diversity. It was once thought that diversity between multiple species was a key factor in gaining a successful colonization, but recent studies have shown it is more important to have diversity within a single species of mycorrhizae. This is due to the fact that mycorrhizae like all life, goes through stages of development. It is important that you have all different maturities of the same species in order to ensure that the spores will be able to correctly associate and reproduce.

For more info on the importance of diversity within a single mycorrhizal species:
Mycorrhizal Symbiosis, Third Edition
Sally E. Smith, David J. Read

Ecto-mycorrhizae are not produced, but rather harvested in forests across the US and abroad. They appear like "puff balls" on the forest floor, usually around old-growth trees. The cost of producing ectomycorrhizae is much greater than the cost of harvesting it. Ectomycorrhizae are readily available and if you live within 10 miles of a forest, it will surely be present in your yard as it is easily dispersed through the air.

If you are growing conifers, oaks, hardwood trees, then you want to use ectomycorrhizae. If you are adding mycorrhizae to your home garden (fruits, veggies, flowers, etc) then you want to use endomycorrhizae. Note � ericoid and orchids require their own unique form of mycorrhizae. Also, nut and fruiting trees respond to both endo and ectomycorrhizal species.

The most effective inoculums currently produced are delivered in their pure form without fertilizer, humates, kelp, and specifically trichoderma (which consume mycorrhizae as a food source when packaged together and left on a retail shelf). Many of these ingredients have their own beneficial effect on plant growth and can mask the potency of the product being used. For incontrovertible results, use a mycorrhizal inoculum which states it is pure, fresh, and alive such as those used by many of the top competitive vegetable growers.

Here is a link that might be useful: Google-found source of pure mycorrhizae


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RE: What do you think about mycorrhizae fungi?

Many trees associate with AMF, maples in particular. While some of the ectomycorrhizal fungi are the "puffballs", many are the common mushrooms people find in the forest, like boletes and russulas. Truffles are EMF as well.

As I pointed out many years ago, an excellent source of inoculum is soil from a healthy ecosystem. The diversity is generally lower in soils that are cultivated, but sow sterilized seeds into almost any soil and the plants will develop mycorrhizae. Certainly plants will benefit from addition of fungal inoculum when propagules are lacking but the vast majority of people have no idea of what is already present in their soil. Glomus intraradices is likely to be present in even the most disturbed soils, while Scutellospora and Gigaspora spp. are likely to be wanting in recently disturbed soils. One would probably be better off adding soil from a healthy forest to restore a woodland than adding commercial Glomus intraradices spores.

If you are growing plants in the mustard/cabbage family don't bother with mycorrhizae because those plants do not form them. Many spring ephemerals don't either. Mycorrhizae are also likely to diminish where fertilizers are applied because the plants will be less dependent on them. The extent of the mutualism also tends to change throughout the growing season depending on the needs of the plants.


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RE: What do you think about mycorrhizae fungi?

Glomus intraradices is endo (AMF). Why would anyone add it to a woodland? Ecto mycorrhizae is extremely prevalent in forests and there is little need to add an inoculum unless you're in the forestry business where successful plantings are crucial each and every time.

Glomus intraradices and other species of endomycorrhizae will not be prevalent in disturbed soil due to the lack of vegetation to survive off of. You may still have numerous hyphal filaments but they ahve a limited life span and will not reproduce. Gigaspora has limited benefits as a species and would not be worth adding to home gardens. It's also worth mentioning that retail companies with mycorrhizal inoculum will often double name the species on their labels to make it look like they have 7-9 species or a higher-diversity (ie. glomus intraradices and glomus aggregatum are actually synonymous, also glomus mossae and monosporum, etc) You can verify this through the link below http://invam.caf.wvu.edu/fungi/taxonomy/Glomaceae/Glomus/intraradices/intrarad.htm (view NOTES section for relevancy)

It is of greater importance to have inner-species diversity (different maturities within a single species). The "shotgun" approach that attempts to rationalize the need for diversity is a fallacy.

Think of it this way. If you were going into battle, would you want a handful of men, women, and children...or would you want 5 marines who are trained and proven to be the best ? The same applies to mycorrhizae. Endo (AMF) associate with roughly 95% of plants. Why not choose the best species, the one that is proven to deliver the best results instead of wasting valuable roots space on less beneficial species (ie the punk kids in front of 7eleven who are basically loitering and have no idea what they're doing)?


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RE: What do you think about mycorrhizae fungi?

Herbaceous woodland plants do not associate with EMF but about 70% of them form AM. Certain trees like elms and maples also associate with AMF and to a lesser extent EMF. The fungi present will vary considerably from one forest type to another.

While soil disturbance reduces the number of AMF propagules in soil, it does not eliminate them. Glomus spp. are more commonly found in agroecosystems than other species of AMF. Gigasporaceae form extensive external mycelia and large spores and are therefore poorly adapted to soil disturbance compared to species that produce limited external mycelia and abundant smaller spores. Glomus mosseae is cosmopolitan and known for being common in disturbed soil. Chances are most people already have it in their soil.

Recent research dispels the old thinking that all mycorrhizal fungi associate equally with all plants. I think one of the earliest studies was this one

Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity van der Heijden et al Nature 396, 69-72 (5 November 1998)


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RE: What do you think about mycorrhizae fungi?

I realize this is an old thread and I have read it all. Since I am not deeply soil structure wise I would like to know if roses that are planted on a previously rocky meadow that was heavily excavated for housing ten years ago would benefit from some sort of mycorrhizial inoculation to the roots when planted. I do not add phosphates or fertilize with anything except fish meal, compost, and untreated alfalfa pellets. I am guessing a reliable source of endo would be the most beneficial, if at all. I am across the street from miles of undisturbed meadow. Could I harvest anything beneficial there?
Mary


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RE: What do you think about mycorrhizae fungi?

I am a hydro gardener and the use of mycorrhizae fungi increases the availability phosphorus and nitrogen dramatically. Reverse.Osomosis water contains no naturally occurring myco fungi or Rhizobium bacterium. Growth will occur readily w/o either but the addition of both root innoculents creates a significantly healthier root environment.


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