I was wondering if anyone could identify this issue or possibly confirm my suspicion.
I harvested some plants with powdery mildew issues recently. When I dismantled my airpots I noticed these black spots in the soil. Can someone tell me what this is?
With all the research I’ve done in dealing with my PM issue I learned that it can eventually turn black on plants if left untreated and that’s when you know it’s gone too far. Is this just PM on the outside of the soil or something else?
Thanks!
It looks as if the Air Pots were put together “backwards” with “pointed dimples” being inward. Did you “flush” out plants before harvesting? If not, possibly “salt buildup”, IMO. Then again, I can certainly be super wrong. SS/BW…mister 
NOTE: Did you determine the cause of the PM issue?
I think that’s just a weird perspective thing in the photo. I definitely had them the correct way. I did flush, for 7 days but I used florakleen.
And no, I’m still trying to figure out the PM issue. I believe it’s air movement but not 100%. My oscillating fan broke and then I had trouble finding a small tent fan that oscillated so I bout a few stationary fans. The PM showed up shortly after that. Looking into a tower fan now.
Haha I’m not familiar with this meme.
I looked it up… I guess you’re implying that I’m shifty? Why?
Take it easy man, was just my reaction to that black stuff, it looks gross, is all. Don’t take it personal now. I don’t know what you’re using and I don’t know much about synthetic nutrients, all I know is that they don’t make sense to me personally, that’s all. I see you’re using organic methods too, might as well go all organic?
Not sure what I did to imply that I wasn’t taking it easy… I was just asking what your meme was all about. It’s all good. I’m not mad just maybe more on the annoyed side of things. I came here looking for help not to be the butt end of a joke. I know you’re just having fun but you have to ask yourself before you post… Is what I’m posting going to encourage this forum to go in a positive direction? Did you think I would see that picture and feel awesome about continuing to post and ask questions here or no? Perhaps maybe it would be more positive for you to offer advice and guidance to someone asking for help instead of making fun of them and encourage a conversation so that maybe we can all learn something.
I think it just follows the pattern of the “air holes” of your airpot, where roots are pruned, could be just salts buildup for lack of roots (you can see them around those holes). Nothing to worry about I guess … 
Cheers bud, ya I was thinking more about it and maybe it’s just build up. I usually see a lot of it when I use fabric pots so I think you may be right. Thanks for the reply.
The coco coir substrate is not cleaned properly, or has become contaminated in transport. It may host aspergillus, fusarium, penicillium species and the like. Using products with simple carbohydrates, like molasses/agave and so on can help feed these organisms. Constant moisture helps in their proliferation as well.
It looks as if the spores of whatever it is were reproducing in the places where airflow was greatest; the tapered side openings and bottom mesh of the air pot each show higher concentrations of mildew present.
The pathogens most likely present no explicit immediate issue to your crops, and the manufacturers of the coir are not necessarily the origin. If you were growing cultivars extremely susceptible to molds/mildews, this source of inoculum may prove an issue. In theory a strain of botrytis may persist through veg and affect flower. But this is unlikely. What is more likely is that some benign harmless spore may cause a microbial test failure, if your crops were being tester for that.
I doubt the same strains which may be harbored in strata will also affect flowers. It is more likely that simple airborne spores affect plants in flower, or living soil type systems with mulch and cover crops which may harbour spores more commonly.
Chances are it’s just some opportunistic mold that decomposes coco coir. It probably hasn’t affected your harvest storability, and there is no reason (except for those who routinely experience urges for excessive precautions) to change/augment anything in your cultivation regime. I wouldn’t even switch coir brands.
Cheers,
-z
Thank you for your knowledge and input!! I really appreciate it. I love learning new things as I go. I’m going to re-read your response a few hundred times and the article and probably get back to you with some questions. Cheers bud!
Besides the PM issue do you think you get better results using the air pots. I have used them in the past using pure Coco coir and organic nutrients. I really enjoyed the ease of transplanting with the air pots. I am trying to convince my roommate/grow partner to use air pots. He prefers the regular kind any thoughts or suggestions. Thank you
I honestly can’t say that I’ve seen an increase in quality or yield, no but I find them a lot easier to work with. Especially after harvest you just unwrap them and clean them and that’s it! Also, I can fit more together in my space although after my last harvest I noticed the yield of 4 air pots (3.35gal) compared to 2 fabric pots (5gal) was a bit smaller. I have a feeling that had to do with my PM issue though. So they’re not going to make you a better grower but in the end they are easier to clean. They are also a bit taller than fabric pots, so keep that in mind if you have a space constraint.
Couldn’t properly reply until now…
I did feed some carbs so that may have contributed. I did rinse the coco before use though… I always do even though it says pre rinsed on the package! Don’t trust that boloney at all.
I have a feeling the PM spores showed up after I brought in some outdoor to dry last fall. Stupid mistake but I had nowhere else to dry the crop. The PM showed up a few weeks after they were hanging outside beside the tent. Now, PM has been showing up in the last few grows. Real pain in the butt… I tried heat stressing the tent by placing a heater in it for an hour and hold it at 32C. That didn’t work bc the PM showed up again. I recently purchased a UVC light so we’ll see if that makes a difference.
Anyway thanks for taking the time to respond. I may just toss that coco away and not reuse it like I typically do… not worth the hassle.
Cheers bud!
Heat pasteurization of rooms is a great practice. In greenhouses most often done between 60 C and 70 C. But indoors is applicable too. A temperature maintained between 60 - 70 C for 1hour will kill pests, eggs, and pathogens.
If plants are in the space, you may heat the space to 40 C for 1 to 2 hours. Maintain observation of the plants during this time, and be ready to ease heat stress if a cultivar begins to show signs of severe stress.
(General advice: Pulling shadecloth over the greenhouse, supplementing with CO2, or using water soluble calcium, silica, and nettle foliars will help deal with heat stress.)
Heat treatments are a great tool. Lot of worry about using them. Largely depends on the plant’s vascular system health. If it can handle the heat, it’s a great option. Anyone in living soil beds or growing NLD genetics, would not worry about plants handling the temperatures. Only the BLD in plastic pots or for example DWC would I worry. A challenge to keep the reservoir or root zone temperatures healthy while heat treating in those systems. But living soil in 15gal+ containers with mature plants does fine. Just keep an eye on it every time you heat treat.
If you want some more confidence in it, I found a cool article on Ed’s website:
" Introduce a temperature spike
Powdery mildew is also controlled through close attention to temperature. Both types of fungi that cause powdery mildew are sensitive to heat and stop growing when temperatures range over 90°F (32°C). They quickly perish when the temperature rises to 100°F (38°C). Introducing a temperature spike to kill powdery mildew can be implemented, but if it is done improperly it could be detrimental to the plants.
“By using the preventive measures and solutions, you should be able to control these debilitating diseases that would destroy your buds. You will minimize losses even if the environmental conditions are favorable to the pathogens.”"
Thanks for sharing the info! I believe I must’ve read that article or something similar in my search for a solution to the PM problem because everything you wrote sound really familiar to me.
I could probably Google but what are NLD and BLD genetics? Something to do with equatorial proximity?
