Citric acid foliar spray for powdery mildew?

[troutman]

Wish somebody could sell 22 spot ladybugs that eat PM.

Powdery Mildew Predators

Somebody has get the ball rolling and market these two ladybugs. In Europe, there's a ladybug that eats mildew. It's the 22 spot ladybug. (Psyllobora_vigintiduopunctata) Unlike most other ladybirds which feed on aphids, P. 22-punctata eats mildew...

www.icmag.com

 

[linde]

LOL more mythology....... milk nor neem "Kill" powdery mildew.
I've seen it under high power microscope.
These sprays only mask the problem and remove the PM you see which is the fruiting spores.
Powdery mildew infects the stomata and then spreads it's mycellium through the tissue on a microscopic level.
40 days after infection the PM colony is able to fruit spore spots on the vegetation.
Neem, milk and other snake oils do not kill PM on the microscopic level....... I'd bet my entire seed collection on that fact. And I have a massive seed collection.
Micronized sulphur spray ...... now that actually kills and rids the plant of powdery milder...... period..... end of story.

2 weeks from harvest in my harsh climate and not a speck of powdery mildew and there is only one reason for that.

Oh so you're a scientist now? Let's see some proof Mr millennial know it all. I'll bet you MY SEED collection that I've been growing cannabis longer than you've been alive on this planet Jack! Lol. Funny shit

 

[Tynehead Tom]

Oh so you're a scientist now? Let's see some proof Mr millennial know it all. I'll bet you MY SEED collection that I've been growing cannabis longer than you've been alive on this planet Jack! Lol. Funny shit

name calling gets you nowhere with me you little punk

you stick to your neem and milk LOL

 

[linde]

name calling gets you nowhere with me you little punk

you stick to your neem and milk LOL

Your right I'm sorry. You must know it all. 3700 posts in 6 yrs! Damn dude there's more to life than cannabis. I'm out of here. Good luck.

 

[shishkaboy]

Athena ipm

 

[mountainoutlaw]

Well the alkaline water did absolutely nothing...im close to chopping, but if i had time id try the citric acid soybean oil mix...

 

[EastCoastGambit]

LOL more mythology....... milk nor neem "Kill" powdery mildew.
I've seen it under high power microscope.
These sprays only mask the problem and remove the PM you see which is the fruiting spores.
Powdery mildew infects the stomata and then spreads it's mycellium through the tissue on a microscopic level.
40 days after infection the PM colony is able to fruit spore spots on the vegetation.
Neem, milk and other snake oils do not kill PM on the microscopic level....... I'd bet my entire seed collection on that fact. And I have a massive seed collection.
Micronized sulphur spray ...... now that actually kills and rids the plant of powdery milder...... period..... end of story.

2 weeks from harvest in my harsh climate and not a speck of powdery mildew and there is only one reason for that.

So I was just digging around the interwebs and cannot find info to back some of your claims.

* Powdery mildew infects the stomata.
* 40 days for inoculation

https://extension.colostate.edu/docs/pubs/garden/02902.pdf

Powdery Mildew

Powdery mildew occurs on many different flowers, woody ornamentals and trees.

extension.psu.edu

https://www.tandfonline.com/doi/full/10.1080/07060661.2020.1836026

This study above is the most comprehensive one I have seen. It suggests bacterial controls as well as UV-C light to be the most effective. Boric acid was not great. Citric acid with fermented juice could contain some beneficial bacterial strains but that is just a guess.

My leaves are still clear thus far. Fingers crossed.

 

[EastCoastGambit]

I actually have a UV-C wand I bought to manage eczema but do not use really. I guess I would try that in a pinch but since it is known to cause mutations I would probably avoid that until a last resort.

 

[mountainoutlaw]

The ONLY time out of 20 plus years of hardcore growing...every type of medium, strain, ect ect..PM has only been an issue in the great outdoors...

 

[mountainoutlaw]

The ONLY time out of 20 plus years of hardcore growing...every type of medium, strain, ect ect..PM has only been an issue in the great outdoors...

Also budrot . Only outdoors.

 

[EastCoastGambit]

Also budrot . Only outdoors.

same, well not the 20 years part, but only time with PM mold or B. rot was outdoor. My indoor have never had that issue, knock on wood. I have had fungus gnats and spider mites indoor though.

I also dont put a lot of effort into strain selection for outdoor. I kind of just throw a couple plants out and hope for the best. I intentionally (now) keep them on the smaller side. Have had good luck thus far.

 

[EastCoastGambit]

So hopefully not hijacking the thread, but to report back. I sprayed again (citric acid) two days ago, however; we had a long sustained raid event all that evening and through Monday into the evening. Sun is back out today thankfully.

I noticed again some minor PM on a few leaves. Its inconclusive if the spray is controlling it but its definitely not eradicating it. I kind of assume if I was doping nothing that the situation would be worse.

That said, I'm going to hit them with the Sodium Bicarb treatment this evening.

Considering the study above showed bacterial approached to be pretty effective it would be awesome to find/develop a strain that both controls for catepillars and PM in one application.

 

[goingrey]

So hopefully not hijacking the thread, but to report back. I sprayed again (citric acid) two days ago, however; we had a long sustained raid event all that evening and through Monday into the evening. Sun is back out today thankfully.

I noticed again some minor PM on a few leaves. Its inconclusive if the spray is controlling it but its definitely not eradicating it. I kind of assume if I was doping nothing that the situation would be worse.

That said, I'm going to hit them with the Sodium Bicarb treatment this evening.

Considering the study above showed bacterial approached to be pretty effective it would be awesome to find/develop a strain that both controls for catepillars and PM in one application.

How strong of a solutions have you used, of the citric?

 

[foomar]

Get PM outside every year from september on and have tried a number of remedies with mixed results.

Water dispersible sulphur up to two weeks in flower controls well and i detect no sulphurous taint in the smoke.

Copper based / Bordeaux mixture good in late veg and usually lasts to the end , again no taint but longterm not best practice to be throwing copper into the soil.

Commercial agro fungicides for edible crops like strawberry with a spray till harvest licence have worked but not entirely convinced of residuals if smoked.


So this one looks interesting

Amylo-X® WG

A water dispersible granule containing 250 g/kg Bacillus amyloliquefaciens subsp. plantarum strain D747 for the control of powdery mildew and other fungal plant diseases on a range of crops grown under permanent protection with full enclosure.

Will cadge a bit off a fruit grower i know and see.

 

[EastCoastGambit]

How strong of a solutions have you used, of the citric?

.13 grams per liter. Seems like nothing but I was trying to copy the dilution rates (for cannabis) of the product that someone else posted.

https://www.aefglobal.com/pdf/Label_Cyclone_en.pdf

Lets check my math

Cyclone: 10.73 grams per liter

for cannabis dilute to: 1.2% (not sure I trust a company that cant spell MJ? LOL)

10.73 x .012 = .12876 grams/liter?

 

[EastCoastGambit]

Next year I will

A: source earlier finishing and more appropriate mold resistant strain for outdoor (mostly because I am also trying to help out and mentor an old timer how to grow outdoor)

(to my credit/discredit I am selfishly testing out my cross that I thought could be a good outdoor candidate in my area)

B: take more preventative measures (potentially water soluble sulfur) before the onset of flower.

 

[TimeKeeper]

I like to breakdown the options for PM control into four groups ranked by effectiveness :
1- Sulfur(micronized wettable, sulfur burners)
2- Oil based products(green cleaner, lost coast)
3- Biological Fungicide(Cease, Double Nickel, Milk)
4- pH adjusted water/enzyme products(Dr. Zymes, Flying Skull, Citric Acid, Bicarbonate)

They all have a place in a solid IPM program. You have to be able to choose what you need for your particular situation. Whether you are growing large scale commercial indoor, outdoor, or small home grow, the fundamentals are still the same. If you stick to a good preventative spray schedule, have good environmental control, and keep up on canopy management, you should't see much PM pressure.

But if you do have PM in mid/late flower my plan would be a few sprays of oil based product until about week 7 and then spot sprays with pH adjusted product or just plain water.

 

[Tynehead Tom]

go look up Joecrowe on overgrow.
He has a high powered microscope and is doing intensive PM studies. Not just for Cannabis either.
He is collecting infected plant tissue wherever he can find it and observing the strains under high power.
Now I may not be a science guy.... I was growing weed before most millenials were out of diapers.... but that is neither here nor there.
Joecrowe has analyzed cannabis specific PM , taken the high rez pics to show people and then applied all the various remedies he can find that growers are using for PM. One after another fails to kill the infection. Except when it comes to sulphur spray. Not only does it kill the spores , it kills the infection enirely.
He shows it clearly under the microscope with big pictures to prove what is going on.
He even says right up front that he went to his local universities agriculture prof and even that guy reacted "exactly" as you are all reacting.

Look I am a simple grower and a little fish in the big sea breeder...... I would never intentionally post wrong information. My ONLY purpose here is to share something that despite what the naysayers nay about..... this shit works and can rid your entire yard of PM if you care to spray that large of an area.
Wettable/micronized sulphur is cheap..... like 15 bucks for a can/tub and you only use max a teaspoon per gallon.
Using this technique I completely eradicated PM in my greenhouse and a 20ft perimeter around it. Took about an hour and about 2.00 worth of the 15 dollar can. With another 2 dollars worth of that 15 dollar can I sprayed my grown rooms , plants and pots for the outdoor season. I put sulphur powder in my soil mixes at the begining of the outdoor season.
I put my entire onlie reputation on the claim that what I am telling you is not only the truth..... it works to eradicate the problem not just "significantly reduce" the problem like the last part of the yellow highlighted quotes above.
Don't spray it during flower but if you are in an area where PM plagues you...... try it..... what harm can there be.
If it takes one grower at a time, we will get this message out there and PM will no longer be a plague in so many peoples harvests.
I will leave you all with that. I don't care to do the back and forth bullshit. Learn or lose I guess.

 

[xtsho]

Citric acid will kill the PM that's on the surface of the leaf. It's not going to completely eradicate it without continuous spraying which can lead to other issues. It's a safe treatment to keep it from spreading even late into flower.

 

[foomar]

As a keen grower of diverse plants have been led to beleive since the 1970,s that a high leaf surface PH was the key to controlling powdery mildew without useing fungicides , citric being the opposite have never tried it specifically for PM.
I have used citric as a most excellent remover of spidermites in late flower used as follows.

Mist the plant all over to runoff , if in pot tilt to 45deg or as low as possible to get underleaves.
Sprinle/dust all surfaces with bicarbonate of soda , very fine powder best shaken through a cloth , and leave a few moments.
Spray with 10g/litre citric acid , the violent foaming action from the CO2 released dislodges the mites and their eggs , rinse off well and minimal plant damage and no nasty residues.

Any unseen bud munching catterpillars also get flushed out as a bonus.

Possibly this could dislodge surface mildew to a usefull extent , and leave the surface neutral/alkaline.