Diatomaceous earth and mycorrhizae?

[RJG2]

Recently I've seen references that state DE has anti fungal properties. I haven't dug too deep, but Harry H mentions it here:

An Introduction to Bonsai Soils – Bonsai4Me

bonsai4me.com

That being said, has anyone seen problems with DE with species that benefit more from their mycorrhizae relationship like pines?

 

[PA_Penjing]

Huh, cool, glad I switched to pumice and bark. I have grown trees in 8822 and never noticed myco fungi but non of them were pines. I would bet if you diluted it enough in the mix the fungi would pop up.

 

[RJG2]

Huh, cool, glad I switched to pumice and bark. I have grown trees in 8822 and never noticed myco fungi but non of them were pines. I would bet if you diluted it enough in the mix the fungi would pop up.

I put my JBP clumps from @cmeg1 in pumice and DE - wondering if that was a mistake now.

They're young enough I can probably get away with removing most of it and substituting pumice and bark.

 

[penumbra]

I have noticed no detrimental effects of 8822 diatomaceous earth. I'm sure it is a problem for all nematodes, both parasitic and beneficial, but my mycorhyza on my young pines with about 20 - 30% DE is doing dandy.

 

[yashu]

I started prying into this on another thread last week and couldn’t find anything stating directly that DE was anti fungal except for the occasional anecdote. However, I did find the following;

https://www.groundworkbioag.com/wp-content/uploads/2021/02/GW181002_Rootella_X.pdf

This is an industrial agricultural mycorrhizae inoculant. So this is a soil additive that inoculates the soil with mycorrhizae, the very thing we want in our pines (and others). Examining the attached pdf tells us that the product is 30% active ingredient, Glomus intraradices and Glomus mosseae which are your beneficial fungus. That leaves 70% filler, or vehicle to carry the inoculant into the soil. So guess what that vehicle is…

yep, you got it, diatomaceous earth.

Now we have to ask ourselves; if DE is a fungicide why on earth would a big ag company with all the research choose it as a vehicle for their fungal inoculant???

my guess is they wouldn’t

 

[RJG2]

Now we have to ask ourselves; if DE is a fungicide why on earth would a big ag company with all the research choose it as a vehicle for their fungal inoculant???

So you buy more and more?

Good to know though. Everything I've read does seem anecdotal too, but Harry is a pretty trusted source. I haven't search too hard, but I haven't seen any real research papers yet.

 

[hemmy]

I think @yashu is spot on. I think other authors are making some “logical” leaps that might not hold up. I’m also skeptical of the anti-fungal properties as a particulate that is saturated with water. I think any negative impact on fungus could be from powered DE that has the ability to absorb available water and dehydrate a surface.

I also found mushrooms stores that sell it for various purposes
https://www.mycopath.com/diatomaceous-earth-horticultural-grade-1lb-p-57.html

We should remember that the mode of action against insects is mechanical with the ground silica diatoms having sharp edges that abrade the insect’s waxy cuticle. The absorbent nature of DE absorbs the waxy coating. This leads to death from water loss and desiccation.
https://www.ncbi.nlm.nih.gov/pmc/ar...ion for,at absorbing protective waxy covering.

 

[yashu]

So you buy more and more?

Good to know though. Everything I've read does seem anecdotal too, but Harry is a pretty trusted source. I haven't search too hard, but I haven't seen any real research papers yet.

Right, this article was sited on the other thread and unfortunately because of H.H.’s reputation there was some pushback. Even the gurus get it wrong sometimes. Hell, Ryan Neal almost killed his whole garden with compost tea.

 

[yashu]

I have used, do use and will continue to use 8822. It works well for me, it’s inexpensive and my collected pines are doing well in it. If you search “where to find diatomaceous earth” you can see the thread I was referring to.

 

[RJG2]

I’m also skeptical of the anti-fungal properties as a particulate that is saturated with water. I think any negative impact on fungus could be from powered DE that has the ability to absorb available water and dehydrate a surface.

I think this is the key here as well, and would make the most sense based on the articles I did read.

 

[yashu]

I think this is the key here as well, and would make the most sense based on the articles I did read.

I don’t know about that even. I think in the RootellaX product the DE is also powdered. My guess is that it would have to do with the moisture content as hemmy suggested.

*edit: I mean I agree I misread the comment

 

[RJG2]

I have used, do use and will continue to use 8822. It works well for me, it’s inexpensive and my collected pines are doing well in it. If you search “where to find diatomaceous earth” you can see the thread I was referring to.

I've seen the thread; guess I hadn't read the updates.

 

[TomB]

I’ve seen good growths of mycelium in substrates containing moler clay (same as HH used) as recently as today. I think if you only use it as part of your mix, and make sure it doesn’t stay too wet, it’s unlikely to be a problem.