Myco in DTW coco/perlite

[KonopCh]

I am aware of snake oil, overpriced watered nutes, false claims, etc. in canna business. That's why I have some questions about mycorhizae, but for coco. We know they're good in soil, they break up nutrients etc., but what about coco DTW? We are already using "break down" nutrients, dry salts, so they don't need do that. I know some swear by it, but I am looking more for scientific standpoint or some "side by side" tests to check claims about growth rate, health of plant, and of course yield.

Also I know @Rahz mentioned couple years ago he doesn't go over 70-80 ppm P, because microbes dies at that point. Any papers for that claim too?

@Renfro @Hot Diggity Sog @DoubleAtotheRON @TintEastwood and any other commercial growers (or big scale growers) please come in and discuss if you have some data on this. Not only opinion. Let's debunk myths once after all.

 

[Hot Diggity Sog]

Unfortunately I do not know but am curious.

 

[Rurumo]

There are so many studies about high P fertilizer and its effect on the microbiome. Nothing shows any kind of mass die off. Most studies show that adding a high P fertilizer will suppress the microbiome, but that the effects of all that instantly available P more than make up for it in higher yields. Of course, organic growers would rather just nurture the microbiome and make use of the P solubilizing effect of mycorrhizae, trichoderma, plant growth promoting rhizobacteria, etc. I don't know of any studies done on coco specifically, but I do know from experience that coco can maintain a microbiome as well as any other media. Now as for which of the mycorrhizae, trichoderma, or the PGPRs solubilize P best, that hasn't been studied. In my experience, in the short time that we grow cannabis in pots, indoors, I think that trichoderma sp and the PGPR colonize the media more quickly than mycorrhizae, but I don't see any reason not to use all three. There is a good study showing considerable synergy between mycorrhizae and trichoderma. It's a really interesting topic, I'm looking forward to seeing what others have to say. Many of these work to increase yield not just by solubilizing P, but by inducing systemic resistance in the plant, so they directly increase yields and indirectly, by reducing disease pressure.

 

[KonopCh]

And now I have question for you @Rurumo - what ranges of ppm P do you talking about?

 

[Rurumo]

And now I have question for you @Rurumo - what ranges of ppm P do you talking about?

I can look up the studies I mentioned for you, but they were all done in fields and so I'll only be able to give you the dry measurements they used. I think the big question, which I don't have an answer for, is how useful it is to cultivate a microbiome if you're using straight chemical nutrients. My feeling is that it probably help a plant get established and increase root mass during the vegetative stage (im talking indoor cannabis cultivation), but becomes totally irrelevant during the bloom stage when the PPMs increase-both because the high P suppresses the microbiome and also because there is already more soluble P in the medium than the plant can even use. So I still think it's a good practice to use mycorrhizae/microbes initially in a chemical grow, but they really shine when using organic nutrients-even liquid organic nutrients in coco. You don't need to do a full living soil type grow to take advantage of the microbiome.

 

[KonopCh]

Yea, exactly my words.
It would be really cool to see some side by side with clones.

 

[SnoopyDoo]

I use Great White in Peat. I'd say it does nothing for yield, but it does help prevent root rot and keeps PH in the soil stabile when using chemical nutes. I do feed the soil molasses, but recommend against putting molasses in the rez or using molasses if you're recirculating.