Powdery Mildew questions....

[horton711]

I have 3 flowering plants and two 1 week old seedlings in a 4 x 4 tent. The flowering plants are just about ready to cut. Today I was taking some samples from one plant to check trichomes and noticed what I am pretty sure is PM on the buds (sort of looks like tent caterpillars I used to see in trees up north -- like cotton stuffed in the buds). I can't see anything on the other plants so far. I have removed the suspect plant but now I need to get a game plan in place.....

Started reading and the more I read the more I am getting confused and bent out of shape over losing this grow. Is there anything I can do at this late stage to mitigate the PM? I gather you can't vape / smoke buds with PM but is there anything else I can use the buds for?

Looking forward for a moment, what would be the best thing to do regarding the seedlings?

The tent has an inline fan and charcoal filter, good air circulation (at least I thought it did), the humidity runs ~50% (it's high but I'm in the south), temps are in the high 70's to low 80's depending on time of day. Lighting is 4 - 300 Watt LED's 3 having UV and IR. Running DWC with AN nutes (micro, grow, bloom).

I feel rather dumb for not anticipating this problem especially considering where I am growing. This grow is medicinal for my wife and myself and the thought of having to trash it makes me ill. I will greatly appreciate any help with this issue. I thank you all in advance.........and apologize for the rambling post.

PS -- tried to get pics, but the buds are very frosty and there is was not enough contrast to get decent images -- I'm still working on it. Besides being a lousy gardener I am also a terrible photographer.....lol

 

[krunchbubble]

I have 3 flowering plants and two 1 week old seedlings in a 4 x 4 tent. The flowering plants are just about ready to cut. Today I was taking some samples from one plant to check trichomes and noticed what I am pretty sure is PM on the buds (sort of looks like tent caterpillars I used to see in trees up north -- like cotton stuffed in the buds). I can't see anything on the other plants so far. I have removed the suspect plant but now I need to get a game plan in place.....

Started reading and the more I read the more I am getting confused and bent out of shape over losing this grow. Is there anything I can do at this late stage to mitigate the PM? I gather you can't vape / smoke buds with PM but is there anything else I can use the buds for?

Looking forward for a moment, what would be the best thing to do regarding the seedlings?

The tent has an inline fan and charcoal filter, good air circulation (at least I thought it did), the humidity runs ~50% (it's high but I'm in the south), temps are in the high 70's to low 80's depending on time of day. Lighting is 4 - 300 Watt LED's 3 having UV and IR. Running DWC with AN nutes (micro, grow, bloom).

I feel rather dumb for not anticipating this problem especially considering where I am growing. This grow is medicinal for my wife and myself and the thought of having to trash it makes me ill. I will greatly appreciate any help with this issue. I thank you all in advance.........and apologize for the rambling post.

PS -- tried to get pics, but the buds are very frosty and there is was not enough contrast to get decent images -- I'm still working on it. Besides being a lousy gardener I am also a terrible photographer.....lol

Little ozone generator or a nice 8-10% hydrogen peroxide spray will get rid of PM in late stages of flowering,,,,

 

[horton711]

Thank you krunchbubble......

a little update..... I've been "dissecting" a couple of buds and have found that the PM is sparsely distributed. Only found a few pockets but I'm sure that doesn't mean that spores aren't all over the place. Dang.....

Will 3% H202 do any good? The closest store where I can get stronger H202 is quite a distance from me and I can't get there until tomorrow.

 

[soil margin]

How close are you to harvest? Or a better question is how long can you wait to harvest at maximum?

A spray mix of 10% milk/90% water will get rid of existing powder mildew and prevent any more from forming. (Make sure to get everywhere, tops of leaves/bottom of leaves/etc. Also after you spray, make sure to shake off any significant excess liquid off the buds so they don't mold)

My advice would be spray the plants heavily, wait 48 hours, spray the plants again, wait another 48 hours and then come back and spray them with plain water to get any milk residue off. Should take care of any PM cheaply and organically without noticeably altering the final medicine.

 

[horton711]

Thanks, soil margin...... Today I'd estimate ~30% amber trichs so I have a little while but not weeks -- at least that's my guess.

Would I use whole milk? Or will skim do the job?

Anything I can do with the buds I took off to assess how much PM I was dealing with?

The milk / water sol'n sounds like a "gentle" means of getting rid of the PM but right now I'd like a "nuclear PM spray" to help settle my nerves..... lol

Again, my thanks for the replies....

 

[soil margin]

Skim milk will do the trick as well. I know it does sound like a hippie remedy but it was actually made popular by commercial organic wine growers who were fighting large scale mildew/fungus and it's quite effective. I've used it myself and was never disappointed in the results.

https://www.sciencenews.org/blog/food-thought/dairy-solution-mildew-woes

 

[Mikell]

Jesus Christ.

At 30% amber, don't spray fucking milk.

A: Confirm before treatment, of any issue at any stage in plant development.
B: Figure your camera out or let fly your descriptive powers. Sounds more like bud rot anyway.

Failing that, treat as per KB's instructions and flick anything suspect into the compost at trim time (yesterday).


The longer you wait, the more time it has to spread. If it is actually an it, that is to say.


Nuclear is a bandaid for veg, a remediative step. Pathogens are everywhere, giving them a foothold is the source of the problem.

There's a lot of reading involved, little of it on cannabis websites or forums.


site:*.edu in the search bar makes Google much more useful.

 

[justanotherbozo]

i also have used milk to successfully battle powdery mildew so i KNOW it does indeed work, as does the H2O2 suggested by krunchbubble and in fact, Jorge Cervantes has a video posted on YouTube demonstrating how to take a powdery mildew infected plant and wash it after harvest in a hydrogen peroxide bath as a way to salvage the crop.

anyway, here's a link to that video and some additional information on the use of milk as a fungicide that i found back when i did my battle with pm back in the day, thankfully i've only had to deal with it once.

Jorge Cervantes: Washing Away Powdery Mildew

peace, bozo

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​

Milk is a useful fungicide in the garden, and is more effective than standard chemical brands.


Researchers believe the potassium phosphate in milk boosts a plant's immune system to fight the fungi.

Where most organic gardeners use a baking soda, soap and oil solution, milk may be substituted to combat the unwanted fungus.

Preparing a Milk Solution and Spraying Schedule

The correct dilution and spraying schedule for garden plants depends on the situation and takes some trial and error.

A milk fungicide solution can range from 1 part milk to 9 parts water, to a strong, milk-only solution. A 1:1 dilution may work for a week, but a 1:8 solution requires spraying every 3 or 4 days.

Skim milk may work better than whole milk, as the higher fat milk may clog a sprayer; even reconstituted powdered milk works.

Uses for Milk Fungicide

Milk was originally used in the garden to treat powdery mildew on squash plants. It is now also commonly used on flowers such as rudebekia (Black-eyed Susans) and Begonias to cure powdery mildew.

Milk has also been used to cure Botrytis on a Cyclamen houseplant. This was applied full strength every morning (leftover breakfast milk). Rotten leaves were picked away and the plant pulled through with no more Botrytis.

Black spots and rust on roses can be controlled but not cured with milk. Fortunately, milk can prevent the spread of these fungi to other plants and new leaves. This can be very useful when bringing home a plant from the nursery and finding a black spot.


The copyright of the article Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in Organic Gardening is owned by Deborah Turton. Permission to republish Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in print or online must be granted by the author in writing.


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by Arzeena Hamir
Powdery Mildew

Less than 3 years ago, researchers in South America discovered a new alternative to controlling powdery mildew. Wagner Bettiol, a scientist from Brazil, found that weekly sprays of milk controlled powdery mildew in zucchini just as effectively as synthetic fungicides such as fenarimol or benomyl. Not only was milk found to be effective at controlling the disease, it also acted as a foliar fertilizer, boosting the plant's immune system.

Powdery mildew in the cucurbit family is caused by the organism Sphaerotheca Fuliginea. It is a serious disease that occurs worldwide. For decades, organic gardeners had to rely on making a spray from baking soda to control the disease. Now, instead of measuring out the baking soda and combining it with a surfactant (a "sticking" substance) of either oil or soap, gardeners need only head for their refrigerators.

In his experiments with zucchini plants, Bettiol found that a weekly spray of milk at a concentration of at least 10% (1 part milk to 9 parts water) significantly reduced the severity of powdery mildew infection on the plants by 90%. While some gardeners may be tempted to increase the concentration of milk for more control, Bettiol found that once concentrations rose above 30%, an innoccuous fungus began to grow on the plants. How does milk control powdery mildew?

Scientist aren't 100% sure how milk works to control this disease. It seems that milk is a natural germicide. In addition, it contains several naturally occurring salts and amino acids that are taken up by the plant. From previous experiments using sodium bicarbonate, potassium phosphate, and other salts, researchers have found that the disease is sensitive to these salts. It is possible then, that milk boosts the plant's immune system to prevent the disease.

Milk used around the world
The benefits of using milk to control powdery mildew haven't been isolated to Brazil. Melon growers in New Zealand are saving thousands of dollars every year by spraying their crops with milk instead of synthetic fungicides. The melon growers in New Zealand have been so successful that the wine industry is taking notice and beginning experiments using milk to control powdery mildew in grapes.

What kind of milk should be used?
In Bettiol's original experiment, fresh milk was used, straight from the cow. However, this is obviously not feasible to most home gardeners. The research work in New Zealand actually found that using skim milk was just as effective. Not only was it cheaper, but the fact that the milk had no fat content meant that there was less chance of any odours.

Wagner Bettiol's original article was published in the journal Crop Science (Vol. 18, 1999, pp. 489-92).

 

[marrdogg]

Jesus Christ.

At 30% amber, don't spray fucking milk.

A: Confirm before treatment, of any issue at any stage in plant development.
B: Figure your camera out or let fly your descriptive powers. Sounds more like bud rot anyway.

Failing that, treat as per KB's instructions and flick anything suspect into the compost at trim time (yesterday).


The longer you wait, the more time it has to spread. If it is actually an it, that is to say.


Nuclear is a bandaid for veg, a remediative step. Pathogens are everywhere, giving them a foothold is the source of the problem.

Was gonna say same thing pm DOES NOT look like cotton. PM doesn't "get in" your bud more like settles on top and listen to this cause it's really, really important, pm is white not fluffy like cotton and gray, it's just plain white like some cocaine on ya leaves.
MOLD!
PEACE!

 

[marrdogg]

I would chop and cut my losses before that shit spreads. Clean with bleach and physan20 if you can find. Clean spray every thing. Sounds crazy but lysol on ya wall goes a long way!.
PEACE!

 

[marrdogg]

Also that's a good tip on the pm krunch as I got a personal issue with that shit and got a little commercial ozone generator collecting dust.
PEACE!

 

[soil margin]

Jesus Christ.

At 30% amber, don't spray fucking milk.

This sounds more like superstition than science. Why not spray milk at 30% amber? It's a 10% solution that is organic, easily rinsed off, leaves no visible residue, no taste/flavor and no reduction in potency. I've done it with my crops and seen other growers do it as well, so please explain what the problem is.

 

[horton711]

Thank you for all the replies..... I'm feeling pretty stupid after reading the replies. I'll do my reading as suggested and try to be more certain of what I'm dealing with in the future.....
What is the expression??? "Make sure brain is engaged before putting tongue in motion"....

I will also try to get some pics -- with my physical issues it's not just understanding the camera but also getting my hands to do my bidding.....I am trying my best and not meaning to be lazy about seeking information.

 

[Useful Idiot]

Thank you for all the replies..... I'm feeling pretty stupid after reading the replies. I'll do my reading as suggested and try to be more certain of what I'm dealing with in the future.....
What is the expression??? "Make sure brain is engaged before putting tongue in motion"....

I will also try to get some pics -- with my physical issues it's not just understanding the camera but also getting my hands to do my bidding.....I am trying my best and not meaning to be lazy about seeking information.

Don't ever feel stupid for asking questions. There is a ton of knowledge to be had here...and lots of great folks willing to help.


I 'm not sure how many posts you need to post pics...that would help us a bunch. Look around plant infirmary and see pics and compare them to what you are seeing on your plants as far as mold.

 

[horton711]

Thanks for the kind words UI.... sometimes being a newbie on a forum can be a daunting experience....lol

Here are a few pics -- not very good quality but hopefully they will help. I "pried" the bud open to try and get a better view. Looking at the bud externally I can't see anything -- it's when I move things around that I can see white / gray..... maybe cotton was not the best descriptor...

 

[krunchbubble]

Thanks for the kind words UI.... sometimes being a newbie on a forum can be a daunting experience....lol

Here are a few pics -- not very good quality but hopefully they will help. I "pried" the bud open to try and get a better view. Looking at the bud externally I can't see anything -- it's when I move things around that I can see white / gray..... maybe cotton was not the best descriptor...

Thats bud rot....

 

[horton711]

Well, at least I have learned something today not that I wanted to.....lol

OK, now that I know what is it, should I dump only affected buds, dump the whole plant, or dump the whole grow? I'm not being facetious, I want to make sure I get rid of this "thing"...

Thanks again for helping me!!

 

[krunchbubble]

Well, at least I have learned something today not that I wanted to.....lol

OK, now that I know what is it, should I dump only affected buds, dump the whole plant, or dump the whole grow? I'm not being facetious, I want to make sure I get rid of this "thing"...

Thanks again for helping me!!

You can pick out all the nasty stuff and try to salvage any good bud...

But you never know if spores made it on that....

 

[Useful Idiot]

Well, at least I have learned something today not that I wanted to.....lol

OK, now that I know what is it, should I dump only affected buds, dump the whole plant, or dump the whole grow? I'm not being facetious, I want to make sure I get rid of this "thing"...

Thanks again for helping me!!

Yeah man...just like Krunch said....bud rot. Salvage what you can at this point...be very careful not to keep ANY that has that shit on it.

 

[horton711]

I shall start the salvage operation.

Going to consider this a learning experience!!

Thank you so much for all the help and suggestions. I hope none of my words did not offend anyone who tried to help......