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Seattle, WA

Hey everyone,

Just thought I'd send an update on some of the latest findings I've had since I started researching commerical mycorrhiza products. It all started when I came across a thread where someone was asking about the "best mycorrhiza product." I posted a link to BioAg's VAM based on my knowledge at the time. I was shocked with how inflammatory people got in regards to any information that didn't support RTI, and also how little actual information anyone had to support their choice (besides testimonials).

The biggest thing I've learned is that it's quite hard to compare products side by side. You can look at spore/propagule counts, but even that won't tell the whole story.

RTI uses g. intraradices, and while the spore counts are not high, they are a fairly inexpensive option. They don't use trichoderma in their mix, which is a good thing, as you want the mycorrhizal infection to occur prior to high P or trichoderma being added to the soil.

My issues with RTI have been that people use them based primarily on their strong marketing and testimonials, without any actual research (I don't consider side by side photos "research"). In addition, when I contacted them via their Facebook page, they blocked me from posting and refused to answer any questions (owner of XTREME Gardening). They also claimed that their Mykos helped a tomato clone root in under 24 hours....complete rubbish.

3/20/2012 12:54:00 PM

Seattle, WA

Since then, I've been emailing with Neil Anderson, the owner of RTI. He has been up front and quite good about addressing my questions, and I've found the dialogue refreshing. Unlike a few of his employees, he seems to have a much better understanding of mycorrhiza and I value his opinion/expertise in regards to our discussion.

While I won’t share the entire correspondence, I will share some of the parts that I think people might find pertinent:

In regards to whether multiple applications of mycorrhiza should be applied to a plant, Neil stated:
the symbiotic association occurs (through) the fine feeder roots.  You are correct, a single application to new roots is all that is necessary and if association occurs, the plant roots are inoculated and additional treatments are not generally necessary, with the exception of giant pumpkin growers.  Because they bury vines to increase root mass, each one of those sites where vines are buried will benefit from further from new treatments. 

Neil also sent me photos, similar to Dr. Mike at Mycorrhizal Applications, showing the efficacy of their product. I don’t consider this to be evidence of much though, without proper controls and scientific methodology. When I started looking at journal articles, the results were mixed. There was one good study that showed single-species dominance (g. intraradices), while another showed good results using g. mossae (which Neil has stated is very genetically similar to g. intraradices).

3/20/2012 12:54:22 PM

Seattle, WA

Overall, I would say that there’s just not enough information out there to say whether it’s best to use a diverse species mycorrhiza like Mycorrhizal Applications MAXX or Bio Ag’s VAM, OR single species products like the ones from Soil Secrets, Premier Horticulture, or RTI.

Personally, I will lean on the side of diversity until I see some good research that shows otherwise. It would be best if someone did a study with giant pumpkins. I’m inclined to think that while g. intraradices will work well in most instances, having a diversity of mycorrhizal species in the mix will compensate for varying environmental conditions across different gardens/patches.

That being said, if you are on a budget and are debating whether to use mycorrhiza in your patch or not, I highly suggest you do so! Just be sure to only use it as a 1X application to the roots of your plant (with the exception being when burying vines). You also only need to add it directly to the roots, it does not need to be spread all over your patch, and ideally it’s not watered in from the surface. You want to put it down in the hole with the roots when transplanting. RTI seems to have the cheapest myco product on the market from what I’ve seen (there are others with higher spore counts but they’re more expensive).

Keep in mind too that if you are using a cover crop in your patch, you will most likely have active mycorrhiza, which is going to be better than any commercial product. 90% of plants have this association and we didn’t even know about it until a decade or so ago! Obviously it’s a highly successful relationship without any human intervention.

Well I hope that people will find the information helpful!

Cheers,
Tad

3/20/2012 12:54:43 PM

Seattle, WA

PS: I’d like to ask Tom to not comment on my thread unless you have something informative to share and can do so without any rude comments or attacks. I have yet to see the so-called myco test that RTI won that you refer to but refuse to share.

PPS: Here’s the thread that sparked my research and where I’ve shared the bulk of my findings: http://www.bigpumpkins.com/msgboard/ViewThread.asp?b=10&p=417609

3/20/2012 12:54:48 PM

Baker City Oregon

Thank you! Very enlightening, informative and interesting.

3/20/2012 1:50:01 PM

(You also only need to add it directly to the roots, it does not need to be spread all over your patch)

hmm have you actully been to a pumpkin patch- just asking tad

3/20/2012 3:10:01 PM

Brooklyn Corner, Nova Scotia

Tas stated twice above that it should only be applied to the roots when burying vines.

3/20/2012 5:06:41 PM

Seattle, WA

Don,

Yes I have been to pumpkin patches. I've toured both the Emmons and Ryan Ewing's up here in my area. What does the information I've posted have to do with any of that?

Do you have any information/research that is contrary to what I've posted? Feel free to share on this thread if that's the case.

Just because I don't know giant pumpkins doesn't mean I don't know how to grow plants or garden.

The information you quoted was also supported by Neil Anderson of RTI. To spread it homogenously around your patch would be a waste of time and money in my opinion, which is also why I don't buy potting soils with it mixed in already. Typically they just put enough in to get it on the label, but not enough to get good inoculation. That's why we add it separately,.

3/20/2012 5:36:20 PM

just curious if you knew how extensive roots can grow in a comptition patch. some in starting hole and some used when rooting down secondarys seems to be what most of us do
were all looking for little improvements that with many, if little things can all add up to breaking records ya it can be a little costly im all for saving money but not at that extent where il only add to starting hole-thats just my opinion

3/20/2012 5:51:51 PM

Seattle, WA

The myco grows with the plant though (it's a symbiotic relationship). Not to mention all the dormant and possibly active spores you probably already have in your patch from previous years applications, as well as any native spores.

I see what you're getting at Don, and unfortunately there is not enough evidence to conclusively decide this in regards to giant pumpkins (based on the research I've seen).

I'd rather concentrate the spores where I know they will do benefit, rather than spread them out over a larger surface area where they may never come in direct contact with roots. I heard somewhere a few years ago (I think it was a lecture from Jeff Lowenfels "Teaming with Microbes") that if the mycorrhiza spore is 2 mm from a root hair, it will not form the association and will stay dormant for the life of the plant.

3/20/2012 5:57:20 PM

Okla

You are telling some growers, who follows certain practices, using specific products, that there is not enough evidence, and they have successfully grown pumpkins over 1500 lbs year after year. This should be considered evidence in itself by those who have grown such huge pumpkins using those products. Lets take the top 10 or 20 percent of the biggest pumpkins grown and see how many have used these products, then you will have the evidence you need.

3/20/2012 6:41:30 PM

Seattle, WA

I'm basing my information off of the current body of research on mycorrhiza (based on what I've been able to access and research) as well as what Neil Anderson of RTI stated.

I'm sure there are good growers who have mixed mycorrhiza throughout their entire patch and grown world record pumpkins. However, you have no way of knowing if they got better mycorrhizal infection based on this practice. Just because they're world class growers (no one is challenging their ability to grow a giant pumpkin), doesn't mean there are not more efficient ways.

I don't consider personal anecdotes or testimonials as evidence, regardless of who they come from because there are zero controls in a grower's patch. That's not to say they don't have value, but I don't think that you can claim that there isn't room to learn and grow and improve upon current practices. If we did everything like the world record holders from the early 90s, would everyone still be using tons of synthetic chemicals?

There are definitely trends in the giant pumpkin community in regards to "best practice." I'm not trying to challenge any current growers or say their wrong, I'm just sharing information, take it and do what you will, or you can ignore it.

Cheers,
Tad

3/20/2012 7:43:30 PM

Colorado

Thanks tad-good info.

3/21/2012 12:18:55 PM

President - GPC

SO Tad, interested in your take on this soluable Myco....From what I understand microniZing iZ not a good thing. From other than doing trialZ...iZ there any other way for us to look inside theZe bottles...for quality mycho?

3/21/2012 12:36:08 PM

Washington State

Thanks for the info Tad. I just wanted to make known that our BioGrow Endo Plus made for us by Dr. Michael Amaranthus no longer has Trichoderma added as most growers are using stand alone sources. The 4 species of Endomycorrhizal Fungi in BioGrow are Glomus Intaradices, Glomus Mosseae, Glomus Aggregatum, & Glomus Etunicatum at double last years rate. We also have the Soluble Maxx which you mentioned from Dr.Mike which has 9 species of Endo and 12 beneficial bacteria. We now have Promot Plus which has both Trichoderma Koningii at 30 million colony forming units per gram and trichoderma Harzianum at 20 million CFU per gram.

Thanks, Joel & Mari Lou Holland

3/21/2012 6:51:01 PM

Seattle, WA

Wiz,

I cannot comment on the micronizing aspect, as the only research I've seen on it has come from the companies making the products (mycorrhizal applications). I do know that it has to still come in direct contact with the roots, so it still seems highly inefficient (unless we're talking established plants and you don't have the means to do a root injection).

3/21/2012 7:01:24 PM

Seattle, WA

Don,

You got me thinking and while I'm not convinced that you need to spread mycorrhiza throughout you patch (though I do see you point about the roots going everywhere). My thought while I was running on the treadmill was that it may be worth looking into the growth rates of mycorrhizae in association with the root growth rates of pumpkins. I realize that pumpkins have much higher growth rates than most plants and it seems to apply to the roots as well. If in theory the mycorrhizal association couldn't keep up, then maybe have more dormant spores near the feeder roots could have benefit. Who knows? Just a random thought I had at the gym and thought I'd share.

3/22/2012 1:28:58 AM

Muddy Waters

Very good post!

3/23/2012 8:14:25 PM