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Powdery Mildew - Large scale Greenhouse

Lastdon

Active member
I know Lastdon. People downstream shouldn't have to suffer from these fools arrogance or their ignorance.

I've actually worked in short term contracted risk management positions for conventional agricultural outfits whose greenhouses are measured in acreage, not sq ft.

The OP is obviously lying, has no business being employed in their current position and will continue twisting the narrative to fit the prerogative of protecting their ego.

I've given away much more for free over the years than I have in that single post. Instead of saying thank you, the ass hat has to make another rebuttal justifying their ignorance and failure. Exactly what I expected.

OP and their entire operation clearly have ZERO understanding of IPM strategies.



dank.Frank

There will be lots of opportunities for people to come and clean up their messes. Actually it might be advantageous to set yourself up as

Cropfailurerecovery.com

Save your multi million dollar operation for 250k or

Lose 300,000 sq ft worth of crop.

Remember
In a 4 x 4 area = pound for most people

So 300,000 sq ft area is worth 250k-500k of consultation fees and to do it right. Btw they usually learn the tatic and kick you to the curb after the technique is learned to that is part of the fee.

AGAIN THEY DID NOT BECOME AN LP to make 1000's. They became and lp to earn Billions! Licensed Producers not the normal icmag small time grower.
 

Pepé The Grower

Member
ICMag Donor
Veteran
It is beside a pheno of master kush which is absolutely caked lol and it has 2 spots on the whole plant :)
Then you're probably good to go with it. But do not forget that if your environment become worst there is great odds you will end up with full PM contamination...


Honestly, i know what i would do if i were in your shoes, but i'm not lol.

So, good luck with that:tiphat:
 

dank.frank

ef.yu.se.ka.e.em
ICMag Donor
Veteran
dude calm down

:joint: :joint: :joint:

Sorry. Lousy growers putting on a front, placing people's health at risk, in order to make $$$$$$$ - just does something to me.

It's not like I didn't provide the answer. 99.9% chance OP will never make another post on the site they are so glad to finally be apart of. Why? Because they got what they came for already.



dank.Frank
 

blastfrompast

Active member
Veteran
So your using a greenhouse that was used for growing strawberries...


You are in for some issues now that you are mid swing IMHO.

Especially if they had PM issues with their strawberries as there is at least one variety of PM that affects strawberries and HEMP... LOL

If you would like to chat more send me a DM

Consultation available for a price

Don't delay....whats the worst that can happen...you have a whole test crop you have to destoy cause it wont meet the LP standards.... Then your backers will lose their biz like others locally have lol.....

Good luck

Thanks for the useful feedback.
Yeah the greenhouse design is majorly flawed, just takes time to fix things as crops need to be fully finished and takes construction time.
This one range that I am working in, is a shitting card to be dealt. They were strawberry growers now trying to grow cannabis...nuff said.

But I am working with them to get some better humidity control first and getting their pruning/training practices down. They are doing sea of green method on mass scale and you can feel the lack of airflow, its stagnant.

Many things in the works, just takes time in this industry!
 

art.spliff

Active member
ICMag Donor
Touchy subject, Frank is right once again and although it may sound harsh the opinions and critique here come from experienced growers and cannabis enthusiasts. Making a statement that you are a paid consultant, and then asking how to grow, does not come across as entirely pleasant or sincere, asking for free advice which you are being paid for.

What some of us are seeing is large scale mediocre or failing operations. The fact that you have PM means the grow environment hasn't been maintained properly. Spraying something on the plants to get rid of PM really should only be a secondary or last resort.

Healthy plants will not get sick and a well tended grow will have healthy plants. Spores or sterile conditions are irrelevant if the plants are healthy. If the plants easily become sick the environment is less than ideal. This is basic growing knowledge, not advanced.

Plants can carry disease like root infections which is another reason to grow from seeds or propagate in house. Such diseases may or may not be controlled or show symptoms with environmental adjustment alone (temp, humidity, ventilation, soil). Another way to phrase this - instead of focusing on a PM outbreak, it may be an indication of less than ideal growing conditions.
 
Last edited:

redlaser

Active member
Veteran
So, in general you want to maintain warmer temps, warmer air holds more water than cold air.

68 degree air holds twice as much water as 50 degree air. Humidity will go down if you just raise temps.

Free moisture, in the form of fog rain or dew is required for spores to be produced from acospores, and conidia will form at optimum temps of 70-85 degrees.

I shoot for 68-74 degrees at night, which keeps humidity roughly 58-62. Not as low as I’d like but it works as a compromise with high fuel cost. No pm but .5% loss due to botrytis on some late plants.

The UC Davis ipm powdery mildew index is a one page comprehensive summation on pm, treatment options, and a prediction model based on points given daily after a rainfall or dew event.

Basically, after leaves get wet, if you get 6 hours daily of temps between 70-85, you get 20 points a day, the maximum points per day.

If you get three days in a row of temps 70-85, you get 60 points, and an epidemic is underway.

But until you get to 60 points, if you have a day where you didn’t get 70-85 degrees for six hours, you reset your score to zero.

There’s a little more to it, but not much. Can’t get more than a hundred points total, can’t get less than zero.

I do a lot of what I call burping the baby, venting 3 times an hour for a few minutes, then reheating in between.

Air exchanges along with good horizontal air flow keeps air mixed, and mixed air will not cool below dew point. Always have enough horizontal airflow to eliminate any dead air spots. Dead air spots will have issues first generally speaking.

Obviously don’t skimp on keeping things clean, spores are going to be there anyway though. Being clean will mean the difference between a minor or a major outbreak.
 

redlaser

Active member
Veteran
“Thank you. From the people that will be consuming that crap”

Maybe the author of that note would like to elaborate what they mean by that.

Without an understanding of the life cycle of pm it will never be controlled.



So, in general you want to maintain warmer temps, warmer air holds more water than cold air.

68 degree air holds twice as much water as 50 degree air. Humidity will go down if you just raise temps.

Free moisture, in the form of fog rain or dew is required for spores to be produced from acospores, and conidia will form at optimum temps of 70-85 degrees.

I shoot for 68-74 degrees at night, which keeps humidity roughly 58-62. Not as low as I’d like but it works as a compromise with high fuel cost. No pm but .5% loss due to botrytis on some late plants.

The UC Davis ipm powdery mildew index is a one page comprehensive summation on pm, treatment options, and a prediction model based on points given daily after a rainfall or dew event.

Basically, after leaves get wet, if you get 6 hours daily of temps between 70-85, you get 20 points a day, the maximum points per day.

If you get three days in a row of temps 70-85, you get 60 points, and an epidemic is underway.

But until you get to 60 points, if you have a day where you didn’t get 70-85 degrees for six hours, you reset your score to zero.

There’s a little more to it, but not much. Can’t get more than a hundred points total, can’t get less than zero.

I do a lot of what I call burping the baby, venting 3 times an hour for a few minutes, then reheating in between.

Air exchanges along with good horizontal air flow keeps air mixed, and mixed air will not cool below dew point. Always have enough horizontal airflow to eliminate any dead air spots. Dead air spots will have issues first generally speaking.

Obviously don’t skimp on keeping things clean, spores are going to be there anyway though. Being clean will mean the difference between a minor or a major outbreak.
 

VenturaHwy

Active member
ICMag Donor
Veteran
Well if you are looking for actual helpful comments instead of ridicule here you go. Take one of the powdery mildew plants to another location where you have total environmental control. Then bring the humidity down to 10% or so, with good airflow from fans, and good lighting, adequate exhaust. See what happens.

There are different strains of powdery mildew. The first strain I saw years ago was really weak. Low humidity and the powdery mildew just disappeared.

The second strain of PM was so horrible I call it the Cali Clap. Nothing on this earth short of extreme poisons would get rid of it. Green Cure would slow the PM for about one hour. It loved low humidity. And it loved every single plant in the room. The final stage was when the PM moved from the flower room to the veg room.

So find out what strain you have, that is the first step. If you have the Cali Clap you will have to chop everything down and start over. Also is there some outdoor crops or other greenhouses that have powdery mildew in the area?
 

Buddha1

Member
Veteran
Hi Everyone,

I am new to ICMag but am happy to finally be here!

I work at a 300,000 square foot greenhouse in southern Ontario Canada. It is poly. 150 feet long by 100 feet wide and 30 feet tall.

I am an internal consultant on the greenhouse and am not apart of the grow team. I have been indoor growing for about 6 years now and had great success. I was hoping to get some feedback/advice.

We have been struggling to control Powdery Mildew and am looking for some advice. In terms of air exchange, it is limited. The greenhouse sits around 23 degrees Celsius and humidity is pretty high. All of this is bad for PM lol

Does anyone have any suggestions to help control and reduce the around of PM we are experiencing? We are limited on fungicidal control methods due to regulations.

This is a very common problem with very simple solutions.

•First and for most...Keep your humidity between 50%-55% during the lights on period and 60%-65% during the lights off period. I have done this for years and never needed to use fungicides of any kind...its an expansive procedure, but absolutely necessary to keep your product clean and safe for consumers.

Powdery Mildew exists in all environments at all times, and only begins to grow when its optimal environment is created and present for its spores to take root. So it is very important that it's optimal or perfect grow environment never develop, humidity can be its greatest enemy and can be its greatest allie.

•Secondly...Lightly spray SM-90 or some other product that disrupts the PH on the surface of the leaf every 10-14 days.

•Thirdly...Look into the Clean Light, if you work for a huge commercial producer, then there should be no problem affording this fairly expensive but great product. It is extensively used all over Europe in huge greenhouses with fanominal results. Their are hand held models for small operations and applications and larger over head models that automatically sweep a greenhouse every 7 days.

Here's a link www.cleanlight.nl (which I can never seem to get to work, here at ICMag...lol).

•Forth and foremost...Tell your bosses to start hiring personal such as myself, which have many many years of experiance growing indoor and no formal degrees or education. And that they should paid for there knowledge and years of experiance and not for their lack of over rated inflated educational degrees.

Good Luck...:tiphat:

Peace...B
 

mexcurandero420

See the world through a puff of smoke
Veteran
Never had PM in a greenhouse with several varieties and humidity was very variable too 16 - 100% at night.
Application of rockdust can help or was is not so messy is the foliar use of Sea-Crop.

6 years of indoor experience that's all what you need to be a consultant.

tenor.gif
 

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