Powdery Mildew - Large scale Greenhouse

mexcurandero420 said:

So far as i can see its the cdpr (california department of pesticide regulation) who says what to use and not what to use in Cannabis cultivation.PAA is not on the list of fungicides what is allowed to use in Cannabis cultivation.



Its not about H2O2 or acetic acid like in vinegar, which has a pH around 4.5, but most pesticides contains more than what is said on the label.Another thing is that Cannabis is a total another category than vegetables, its comparing pears with apples.

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The very paper you listed clearly states that it isn’t a complete list and if you read the law anything that is fifra 25b exempt can be used.

To the person who asked why my opinion of other thread participants is that their understanding of plant physiology is infantile can take this as an example as to why.

Lost in a SOG said:

You want uvc hitting the plants.. it kills viruses inside plants as well as things on the surface.

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Thanks for the insight. Most of us here probably keep their grows immaculate but always looking for ways to do better. I don't own a uvc lamp but starting to notice they're gaining popularity. Even in grocery stores around me, the entrance has a uv light before entering the store.

I use a UVC light from c.leanligh.ts.

@mountainkine, you go ahead calling other infantile and spraying shit on your plants, while I will harvest my clean safe weed . It is typical of assholes to revert to such tactics when people don't agree with them.

PAA is not allowed in the EU for food applications and for good reason! Even though its residu is non toxic it still leaves a residu. So yeah as far as fungicides are concerned, they are the safest. But I prefer my cannabis without any residus on them, even if they are safe.....

Mountain Kine said:

The very paper you listed clearly states that it isn’t a complete list and if you read the law anything that is fifra 25b exempt can be used.

To the person who asked why my opinion of other thread participants is that their understanding of plant physiology is infantile can take this as an example as to why.

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That's the grey area between what is allowed to use and what isn't allowed.
To avoid powdery mildew or grey mold during flowering time, its better to choose varieties which are resistant against it and there are varieties which have pretty good resistance against those fungi pests.

Like what is said on the site of cdpr that none of resources what is recommended is federally registered for Cannabis and sure the federal government is still far behind the legalisation issue.Cannabis is still schedule 1, but it means also what is recommended to use has the lack of safety literature at what dose and till when is it allowed to spray.Spraying chelated metals is imo out of the question during flowering time.The only material i would spray but very little is Sea-Crop, but only during the beginning of flowering.

He needs to take care of the environment first huh. Even PM resistant strains would result in bud rot with the poor air exchange and high humidity he speaks of.

MD84 said:

He needs to take care of the environment first huh. Even PM resistant strains would result in bud rot with the poor air exchange and high humidity he speaks of.

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That's a matter of testing varieties in area's with higher chance of fog outside.100 % humidity and no wind.
Varieties high in Limonene or pinene should stand those conditions.Geraniol is another terpene with great antifungi qualities.

It’s all Cannabis so the disease resistance is going to be the same in general but what is going to be subtly different is ability to uptake minerals and assimilate those minerals in to the metabolic system.

Plants that do well against bugs mold etc are all plants that easily uptake and assimilate calcium.

You can spray sea crop all the way to the end of harvest

It seems like potassium bicarbonate is what most commercial greenhouses use. Cannabis, food, ornamentals.
I got no real reservations about smoking bud that was sprayed mid flower with it. It is better to use as preventative but it does actually kill pm unlike sulfur.
Id like to see data on this fancy light.. I wonder if it really can do what potassium bicarbonate does.

Transplanting Clones Outdoors & Kick-Starting Growth! (Candyland Pt 2)
Estes’ Grand Daddy Farms


https://youtu.be/sNNlIgLDKgI?t=347

Potassium bicarbonate

I had problems with mildew outdoors last year, the potassium bicarbonate didn't do much. It slowed it down a bit but didn't stop it from taking hold and spreading. The weather played a much bigger factor. When it was sunny and warm the mildew melted back, when it was cool and foggy the mildew spread like wildfire. The strange part was that it attacked my most mold-resistant plant, a Mextiza. The plant tended to shade itself, lots of fluffy shaded lower limbs.

Once the mildew gets 'down in the sap' of the plant I'm thinking not much can stop it. Sulfur got rid of it indoors, that'd be my go to solution. Potassium carbonate for the very earliest stages as a preventative.

THC123 said:

I use a UVC light from c.leanligh.ts.

@mountainkine, you go ahead calling other infantile and spraying shit on your plants, while I will harvest my clean safe weed . It is typical of assholes to revert to such tactics when people don't agree with them.

PAA is not allowed in the EU for food applications and for good reason! Even though its residu is non toxic it still leaves a residu. So yeah as far as fungicides are concerned, they are the safest. But I prefer my cannabis without any residus on them, even if they are safe.....

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How often do use it over your plants and do you use it flower too. Also what precautionary steps do you take while using the light?

For preventative measure once every 2 or 3 days. Many times I don't do preventative, I wait for the first symptoms and then I do it every day, once the PM dissapears I do it once every 2 days.

I shine the light at about 10-20 cm from the plant 3-5 seconds per spot.

I wear special gloves and glasses and long sleeves.

mexcurandero420 said:

That's the grey area between what is allowed to use and what isn't allowed.
To avoid powdery mildew or grey mold during flowering time, its better to choose varieties which are resistant against it and there are varieties which have pretty good resistance against those fungi pests.

Like what is said on the site of cdpr that none of resources what is recommended is federally registered for Cannabis and sure the federal government is still far behind the legalisation issue.Cannabis is still schedule 1, but it means also what is recommended to use has the lack of safety literature at what dose and till when is it allowed to spray.Spraying chelated metals is imo out of the question during flowering time.The only material i would spray but very little is Sea-Crop, but only during the beginning of flowering.

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You seem confused because if you’ll spray sea crop then there’s no difference in spraying say calcium chloride on the plants.

There’s no grey area at all in what’s legal to use on a California licensed farm.

Maybe you should look up what FIFRA25b exemption is before you say it’s a grey area that can be used to slip in banned substances

THC123 said:

I use a UVC light from c.leanligh.ts.

@mountainkine, you go ahead calling other infantile and spraying shit on your plants, while I will harvest my clean safe weed . It is typical of assholes to revert to such tactics when people don't agree with them.

PAA is not allowed in the EU for food applications and for good reason! Even though its residu is non toxic it still leaves a residu. So yeah as far as fungicides are concerned, they are the safest. But I prefer my cannabis without any residus on them, even if they are safe.....

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What’s the “good reason” it isn’t allowed? I feel like if you knew you’d cite it specifically but instead you just want to bolster your position by using rhetoric like “it’s banned for good reason”

Do you realize that PAA disassociates in to water and co2 ?

I recommend that you read the text of this link

https://eur-lex.europa.eu/legal-content/GA/TXT/?uri=CELEX:32016R0672

Incase you don’t I’ll include the points that are important.

2)
Peracetic acid has been evaluated in accordance with Article 16(2) of Directive 98/8/EC of the European Parliament and of the Council (3) for use in product-type 1, human hygiene biocidal products, product-type 2, private area and public health area disinfectants and other biocidal products, product-type 3, veterinary hygiene biocidal products, product-type 4, food and feed area disinfectants, product-type 5, drinking water disinfectants, and product-type 6, in-can preservatives, as defined in Annex V to that Directive, which correspond respectively to product-types 1, 2, 3, 4, 5 and 6 as defined in Annex V to Regulation (EU) No 528/2012.

Seems like it is approved in EU for all types of uses - like even disinfecting drinking water - for a good reason - this stuff works and is the safest biocides compound one can employ - I’ve been holding this in my back pocket because I’ve been waiting for you to cite something that says it’s banned for use in EU but you just keep on with nothing to back up your claim so today I decided to just pull the law out for you to read.

This is why I use the word infantile in reference to some thread participants - You've got guys running around defending their position based off of emotion and not fact or experience. That is infantile behavior. I don't care if one doesn't agree with me or even if they do. What I do care about is factual information, of which there is VERY little in this thread.

THC123 said:

For preventative measure once every 2 or 3 days. Many times I don't do preventative, I wait for the first symptoms and then I do it every day, once the PM dissapears I do it once every 2 days.

I shine the light at about 10-20 cm from the plant 3-5 seconds per spot.

I wear special gloves and glasses and long sleeves.

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Thanks for the tips thc. I'd like to get the one where it's just the light and the fan or get one installed in my a/c blower. Have you had experience with the stationary ones or just the one you wave over the plants?


https://stoppowderymildew.com/online-store/cleanlight-air/


This is the one that I was looking at. I really just need one to add to my arsenal in my ipm.

Products shall not be incorporated in materials and articles intended to come into contact with food within the meaning of Article 1(1) of Regulation (EC) No 1935/2004, unless the Commission has established specific limits on the migration of peracetic acid into food

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It cannot be used as a fungicide for food crops..... it is used as a disinfectant...

I don't use it anymore because it's a nasty chemical, but the only thing I've found to be 100% effective in eradicating PM from my garden was Myclobutanil (Eagle 20 or Immunox). When I did use it, I only sprayed the clones once when they had roots, and that did it for the life of the plants and and clones taken from the plants. Scary shit, but it works.

indagroove said:

I don't use it anymore because it's a nasty chemical, but the only thing I've found to be 100% effective in eradicating PM from my garden was Myclobutanil (Eagle 20 or Immunox). When I did use it, I only sprayed the clones once when they had roots, and that did it for the life of the plants and and clones taken from the plants. Scary shit, but it works.

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Yup. Your clones still test positive. If your walls got sprayed it is possible every crop grown will test positive.

According to the hazardous material sheet on the stuff makes it pretty clear its bad stuff. Even turns to arsenic when heated. Not bad considering it sticks around forever....... And shows up concentrated in concentrates.

Things like bacillus subtillus and potassium bicarbonate as a tank mix (bicard 1 gramme per litre) work wonders as a preventative programme. I wouldn't recommend spraying in flower but to maintain mothers it would be a great one, the bacillus covers the plant area and prevents germination of spores and the bicard raises the pH of the leaf surface so mildew doesn't want to grow. One time per week is good but if you can evaporate sulfur in the mother room safely, I would say that is the best bet over all (never in flower though)

Limeygreen said:

Things like bacillus subtillus and potassium bicarbonate as a tank mix (bicard 1 gramme per litre) work wonders as a preventative programme. I wouldn't recommend spraying in flower but to maintain mothers it would be a great one, the bacillus covers the plant area and prevents germination of spores and the bicard raises the pH of the leaf surface so mildew doesn't want to grow. One time per week is good but if you can evaporate sulfur in the mother room safely, I would say that is the best bet over all (never in flower though)

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Which brand of bacillus subtilis do you use?