# White Powdery Mildew on leaves...



## OGKushman (Oct 31, 2009)

So my buddy is having bad issues with mildew. It is growing on all parts of the leaves and even the buds. He ripped his entire grow down and started over with some advice from me. He started a new grow in a new room, from the Black and White poly down to the drywall was replaced! 

He is now seeing some lower areas with mildew spots starting again. 


His humidity is 20% during day, 40% at night, and get this...his temps are 60-66 degrees MAX. It is freezing in there. 

But the mildew is still showing up. What can he do?  I am out of ideas. :holysheep:


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## HippyInEngland (Nov 1, 2009)

Hello OGK 

Is he growing in soil?

Is he bringing fresh air in from outside?

What is his weather like outside?

eace:


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## 4u2sm0ke (Nov 1, 2009)

Bring  that  heat  up....Thats  too  cold  to  grow  in...I  bet  they  aint  even  growing...sounds  as  though  he  has  more  issues  then  just  Mildew  ....Tell  him  4u2sm0ke  said  bring  his  arse  and  his pictures  to  us  here...its  best  help  without  middleman...not  that  your  doing  anything  bad...just  he  would  get  Much  help..as  you  all ready  know...Take care and be safe


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## OGKushman (Nov 1, 2009)

HippyInEngland said:
			
		

> Hello OGK
> 
> Is he growing in soil?
> 
> ...


1. Rockwool
2. He was but now has CO2
3. Weather is SoCal. Kinda cool lately but when it showed, temps were high as well as humidity.


The plants look great right now. I hear pure indicas like to be cooler.? He just cant seem to stop it from showing up little by little.


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## NorCalHal (Nov 1, 2009)

PM is prominant here in Cali among the MANY clone vendors. I am not sure if you are making your own cuts, or purchasing them thru a club. If you are getting them from a club, my bet is that is where it is all starting.
If not, you need to treat your mother plants consistently until all signs of PM are wiped out.

I have fought PM for many years and there is only a couple of ways to truly eradicate it ,imo.
One, from the source plant of course.

Once you have plants that show signs, running a sulpher burner is really the only way to get trid of it, but I would not reccomend running it after a couple of weeks into flower.


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## 2Dog (Nov 1, 2009)

Dampness or high humidity
Crowded plantings 
Poor air circulation 

these things will cause it everytime...plus watering on leaves once they are blooming..no misting. 

Improve air circulation by thinning and pruning 
Don&#8217;t fertilized until the problem is corrected. Powdery mildew favors young, succulent growth 
Don&#8217;t water plants from above


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## NorCalHal (Nov 1, 2009)

2Dog...GREAT advice. Everything she said will def help keep it from coming back, once u get rid of it.


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## OGKushman (Nov 1, 2009)

I make him his cuts, and I have no issues?

Humidity is low,
plants were crowded, but he started over and they are still small,
air circ is good....

Will the low temps affect his grow? Will it really help in controlling the PM?

He used a copper soap and has had some inconclusive results.

thanks guys


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## 2Dog (Nov 1, 2009)

I dont know I have never had mildew but I keep my airflow up and my room is in the 70's...


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## OGKushman (Nov 1, 2009)

2Dog said:
			
		

> I dont know I have never had mildew but I keep my airflow up and my room is in the 70's...


Do you filter the intake? What kind of filter? Passive/Active?


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## 2Dog (Nov 1, 2009)

lol no its called an open window and fans...for shame I know...hanging head... my room feels dry unlike a lot of grow rooms.


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## OGKushman (Nov 1, 2009)

2Dog said:
			
		

> lol no its called an open window and fans...for shame I know...hanging head... my room feels dry unlike a lot of grow rooms.


"feels Dry"????

Only way to tell is with a hygrometer!!!

Go to home depot and get one.



> I really like using silicon ALL the time, from day one add a bit to the resevoirs and maybe you can avoid catching it in the first place. Its really easy, cheap, and is a nutrient anyways.
> 
> 
> The challenge is killing the asexual spores called conidia. These are the white "mildew" that is seen. PM also has sexual spores that it releases when it gets cold and it thinks winter is approaching. I think these are called cleistotheca and are little brown sap looking things on leaves that look like thrip turds. The conidia I read can live up to 21 days, the Cleistotheca live months. I think if you have mildew it is better to up the cold nights so that u only have conidia to fight against. These conida are asexual spores that need to live on another plant. They are obligate parasites. In nature they might get blown by the wind into atmosphere when conditions good and land far away and start to grow. In a room they might land on walls or any surface like edges of tables, under tables etc. I have yet to find out if conidia or cleistos can rest in medium and grow onto root for example. But so the spores are on the walls. How to kill them? You can turn off everything for 3 weeks which hopefully the spores will have died. But u do not want to have everything down that long so how can we accelerate this shut down? I think the variables and products might include Sulfur Burners, Ozone Gnerators, high temps and maybe other stuff too.
> ...


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## OGKushman (Nov 1, 2009)

Im chillin here with my buddy and he just enlightened me on some new info.


My friend recently put his a/c on a timer 12/12. He said it was to save energy. Only problem is that his room's night is our day. So, when the problem began, during the light off (night in his room) he tells me the temps are 80 degrees and 65 degrees when the lights come on(day in the room)!

LOL


I think this might be the source problem!  Anyone else?

Now he just has to contain it and get it [email protected]


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## OGKushman (Nov 1, 2009)

oh wow...

good info here to. Considering not much research on Bud Plants has been published, I think other types of unseen infection may be happening.

Check this out:



> Pepper powdery mildew grows unseen, within the leaf tissue for a latency period of up to 21 days. Unlike tomato and cucumber powdery mildew which is easily seen on the top side of the leaves, pepper powdery mildew grows on the under side of leaves (Figure 1). Disease monitoring, early detection and prevention of pepper powdery mildew is critical. By the time pepper powdery mildew is detected in a greenhouse many more leaves are already infected but do not show any disease symptoms or signs. In addition, pepper plants can become defoliated and do not recover as quickly as other greenhouse crops when infected with powdery mildew. Pepper powdery mildew does not infect the fruit or stems but can quickly destroy unprotected leaves and eventually the entire pepper crop.


hXXp://www.agf.gov.bc.ca/cropprot/peppermildew.htm


This is the Leveillula taurica strain, 1 of 2, that only affects Marijuana.



> Send samples of pepper powdery mildew for lab confirmation to the BC Ministry of Agriculture and Lands provincial Plant Diagnostic Lab. Send a representative sample of infected leaves showing mild to severe symptoms and include some healthy appearing leaves.
> 
> Provincial Plant Diagnostic Lab
> BC Ministry of Agriculture and Lands
> ...



WTH...IS this free^^^?


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## SkunkPatronus (Nov 1, 2009)

4u2sm0ke said:
			
		

> Bring that heat up....Thats too cold to grow in...I bet they aint even growing...sounds as though he has more issues then just Mildew ....Tell him 4u2sm0ke said bring his arse and his pictures to us here...its best help without middleman...not that your doing anything bad...just he would get Much help..as you all ready know...Take care and be safe


 
I'm so sorry but your avatar is just so...... distracting...


Been running into all morning... read: looking for it all morning


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## SkunkPatronus (Nov 1, 2009)

OGKushman said:
			
		

> So my buddy is having bad issues with mildew. It is growing on all parts of the leaves and even the buds. He ripped his entire grow down and started over with some advice from me. He started a new grow in a new room, from the Black and White poly down to the drywall was replaced!
> 
> He is now seeing some lower areas with mildew spots starting again.
> 
> ...


 

I find ozone is something that is largely overlooked.  Might read about ozone generator uses, it will kill viruses and bacteria and mold, so probably PM too???


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## HippyInEngland (Nov 1, 2009)

SkunkPatronus said:
			
		

> I find ozone is something that is largely overlooked. Might read about ozone generator uses, it will kill viruses and bacteria and mold, so probably PM too???


 
Ozone gererators also have the ability to damage plants, research is a wonderful thing.

eace:


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## HippyInEngland (Nov 1, 2009)

2Dog said:
			
		

> Dont fertilized until the problem is corrected. Powdery mildew favors young, succulent growth


 
This comment is wrong.

PM will come and attack any growth.

A growth space is like a petri dish, give it ideal situations and it will flourish.

Young, established, old, they will all get its vigour.

Its the dish that attracts it, remove the dish.

eace:


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## leafminer (Nov 1, 2009)

OGKushman said:
			
		

> Im chillin here with my buddy and he just enlightened me on some new info.
> My friend recently put his a/c on a timer 12/12. He said it was to save energy. Only problem is that his room's night is our day. So, when the problem began, during the light off (night in his room) he tells me the temps are 80 degrees and 65 degrees when the lights come on(day in the room)!
> LOL
> I think this might be the source problem!  Anyone else?
> Now he just has to contain it and get it [email protected]



You mean that he runs the lamps at night and has them off during the day? That's what I do. For the reason that day temps can go as high as 30C even at this time of year, but night temps are dropping as low as 12C. The lamps keep the grow room at about 25C at night which the plants love, and during the day they rest, the grow room would be as high as 38C if I ran the lamps in the day. Now, what you said last made little sense related to the first post about the grow room being so cold.


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## CaliWizard (Nov 2, 2009)

i bought clones in sacramento ... have had them since the middle of september. when i got them i learned what PM was. at first it was only on one or two plants. i quickly got rid of them. but now it is STILL here and i have been spraying with Garden Safe Fungicide3 since the beginning. i spray daily and am contemplating tearing out my girls after reading this. 

is there ANY way to get from LEVEL 1 to LEVEL 0 ?? i am definitely at level 1 because it is only on a few leaves so far everyday. but i am going to have to do something within a few days as i am worried of getting sick..


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## OGKushman (Nov 2, 2009)

leafminer said:
			
		

> You mean that he runs the lamps at night and has them off during the day? That's what I do. For the reason that day temps can go as high as 30C even at this time of year, but night temps are dropping as low as 12C. The lamps keep the grow room at about 25C at night which the plants love, and during the day they rest, the grow room would be as high as 38C if I ran the lamps in the day. Now, what you said last made little sense related to the first post about the grow room being so cold.


I am saying that his a/c being off for the night swaps temps in the room.

At night in the grow room (a/c off) his temps are 80-85 degrees

During day, lights on, a/c on, room is at 66 degrees

PM loves dark high humidity places ~80-90 degrees. BINGO

When lights go out so did all fans, a/c and exhaust (he is a power freak). His humidity skyrocketed as did his temps due to the warm garage during the NORMAL day and no a/c. 


I told him to drop the temps when the light goes off by turning off exhaust with a timer, and leaving the a/c to cool on max; it will shut off w/no exhaust to pull out cold air and not cost much to run anyways as it is not cooling the light.



			
				CaliWizard said:
			
		

> i bought clones in sacramento ... have had them since the middle of september. when i got them i learned what PM was. at first it was only on one or two plants. i quickly got rid of them. but now it is STILL here and i have been spraying with Garden Safe Fungicide3 since the beginning. i spray daily and am contemplating tearing out my girls after reading this.
> 
> is there ANY way to get from LEVEL 1 to LEVEL 0 ?? i am definitely at level 1 because it is only on a few leaves so far everyday. but i am going to have to do something within a few days as i am worried of getting sick..


If you see PM patches on leaves, you are at level 2. 

Most are at level 1 and just don't support the right conditions to germinate the PM spore.


*I am happy to report that he is already seeing progress (3-4 days with cold temps). His growth has visibly slowed a little, but no new PM patches!!!!!!!*


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## nvthis (Nov 2, 2009)

Hey Kush, Dutch Master Zone & Penetrator. Heard about this mix on another forum and so far it has done the trick.

You might also try baking soda in a topical or milk (mixed at 1 part milk, 9 parts water) also as a topical. Lots of folk swear by it. Also 3% hydrogen peroxide straight, in a topical. In the same way you might use baking soda you can try your regular ph up in a topical to create and inhospitable environement (along with proper temp and ventilation) at about 9.0. And there is always sulfer.

If you go the Dutch Master route be prepared for the cost of the penetrator. It can be a real dinger after a while. The zone will last for just about ever. It's pink and leaves your room with a peculiar but familiar smell that is not near as offensive as some of the other pay-to-play chemicals on the market. As a major plus there seems to be no adverse affects using it 'til day of harvest.

There are other strategies out that you can try, but, like me, you will have to search them out!


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## CaliWizard (Nov 3, 2009)

so is it safe to assume that a good percentage of bud that is purchased has PM when growing? either in level 1 or 2 ?? along these lines i wondered if i should just kill my girls now? or let them grow and continue to treat with fungicide and adjust conditions? if i do keep growing them, how safe is the PM to smoke? 

overall i just want to know if i should kill my girls now and start over with something NOT infected.


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## CaliWizard (Nov 3, 2009)

i actually just found an Economy sulphur burner for 30$. it burns little 2.5 or 5 gram sulphur discs which are also inexpensive. would this be a good solution? i am probably purchasing this tomorrow..


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## nvthis (Nov 7, 2009)

Gotta link?


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## CaliWizard (Nov 7, 2009)

http://morewinepro.com/search/100486/beerwinecoffee/coffeewinebeer/Sulphur_Products 

there are other sites that have those in stock..


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## nvthis (Nov 7, 2009)

Cool thanks!


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## OGKushman (Nov 9, 2009)

Update:

a/c on full blast the PM is not surviving. I saw it myself and its looking good!

62-65 degrees, plants look good, and no PM visible to me. 

good stuff. He fixed it w/o chemicals!


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## OGKushman (Nov 11, 2009)

I spoke too soon!

He is seeing new patches on the tops of some hidden leaves in the back of the grow.

Anyone hear of copper soap?

I found this. It says to use neem oil, or sulfur burner. And it says copper soap does not work. 





> Oils. To eradicate mild to moderate powdery mildew infections, use a horticultural oil such as Saf-T-Side Spray Oil, Sunspray Ultra-Fine Spray Oil, or one of the plant-based oils such as neem oil or jojoba oil (e.g., E-rase). Be careful, however, to never apply an oil spray within 2 weeks of a sulfur spray or plants may be injured. Also, oils should never be applied when temperatures are above 90°F or to drought-stressed plants. Some plants may be more sensitive than others, however, and the interval required between sulfur and oil sprays may be even longer; always consult the fungicide label for any special precautions.



hXXp://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7406.html


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## nvthis (Nov 12, 2009)

nvthis said:
			
		

> Hey Kush, Dutch Master Zone & Penetrator. Heard about this mix on another forum and so far it has done the trick.
> If you go the Dutch Master route be prepared for the cost of the penetrator. It can be a real dinger after a while. The zone will last for just about ever. It's pink and leaves your room with a peculiar but familiar smell that is not near as offensive as some of the other pay-to-play chemicals on the market. As a major plus there seems to be no adverse affects using it 'til day of harvest.


 
I'm tellin ya bro, give this a whirl man. It has worked awesome so far. And, supposedly, you can use it up to day of harvest. I would go with this before you get into the 'heavy stuff' This took it off both my bubba kush, pre '98 and the reg. The most _pm friendly_ plants I have dealt with yet.


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## CaliWizard (Nov 12, 2009)

so far fungicide will help to get rid of visible patches. sulphur fumes are the only thing that will kill PM. burn a bunch of matches and close the door or get that inexpensive burner i linked above... lowering temps will only slow growth.


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## CaliWizard (Nov 12, 2009)

nvthis said:
			
		

> I'm tellin ya bro, give this a whirl man. It has worked awesome so far. And, supposedly, you can use it up to day of harvest. I would go with this before you get into the 'heavy stuff' This took it off both my bubba kush, pre '98 and the reg. The most _pm friendly_ plants I have dealt with yet.



why would root booster, and leaf penetrator get rid of mildew?


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## nvthis (Nov 12, 2009)

CaliWizard said:
			
		

> so far fungicide will help to get rid of visible patches. sulphur fumes are the only thing that will kill PM. burn a bunch of matches and close the door or get that inexpensive burner i linked above... lowering temps will only slow growth.


 
I hear ya, but don't spray fungicide on buds!! Fungicide is some dangerous bad juju. If the above works and gets me through this grow, then forget sulfer too 

When I worked termite/ag fungicides were always some of the most dangerous chems to mess with. I work with them as lightly and infrequently as possible. Even if daconil looks and smells like vanilla paint!:hubba:


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## OGKushman (Nov 14, 2009)

past few days I have been letting my room hit 100 degrees then I put the air on. As a preventative measure for me, cause I have been visiting my buddies moldy crop. I have not seen 1 patch of mold in my room. He has been doing the same. Will post back on his results periodically. Looks like hes doing good though with getting ahead of the mold.


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## nvthis (Nov 14, 2009)

CaliWizard said:
			
		

> why would root booster, and leaf penetrator get rid of mildew?


 
Yup, can't answer that at all bro! I can tell you from where I stand right this moment that it works like a doggone charm. I read somewhere that this stuff has some natural chemical in it that mimics the action of chlorine and PM gets it's butt handed to itself by said chemical? Maybe the same way it is supposed to 'clense' roots? I don't really know. Regardless, it cost me $60 to try it when I really felt like I had my back against the wall. Now I will tell anyone about it that is in need, str8 up. I will never be without a supply from here on out. It will be a permanent resident in my nute cabinet. I treated for it 3x and haven't seen PM since. I dipped everything I could on the first treatment and sprayed like crazy in four day increments after that. PM done. I will add, though, it doesn't seem to have any effect on thrips at all Oh well. Can't win 'em all.


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