risks of running @ 20% RH

[medthumb]

im running a small closet grow, and ive been battling powdery mildew from clone. im day 35 in flowering, and things are looking very good other than the occasional mildew. in order to reduce the PM ive got a dehimidifer running constantly, which keeps my temps around 85 and the RH around 20%. im growing organically in soil, and really dont want to resort to chemicals.

everything ive seen about PM says to run humidity between 40 and 50. im wondering if im causing more harm by running the humidity so low (im still seeing new PM spots daily). my instinct tells me the lower the humidity the better in this case, but i dont have the experience to tell me whether this is the case. any input is very much appreciated

 

[good drown]

i think you may need to focus on more air movement inside your closet, and do a very thorough cleaning with bleach. if you can, empty out the room, clean every surface with a bleach solution. If you can't do that now, do it after you chop, and do a damn good job.
ideally you want your humidity to be no more than 40% in flower,or you can get mold.
what kind of setup do you have? what kind of lights, the watts, any intake or exhaust fans, any circulation fans? is there carpet? also, do you live in a humid area?
mold sucks big time, nothing worse than harvesting a crop and finding mold in the middle of the big buds

 

[guest2012y]

Organic PM spray developed by me and CC..(with influence from Mad L.)
Per 1 gallon non-chlorinated water:
1/4 cup Lactobacillus culture (make it yourself)
1/4 cup Dyna-Gro silicone
A few drops Dr. Bronner's peppermint soap
Spray before lights go off if in flower,stinks like cheese,but goes away after a couple days...safe for flowers. Spray anytime you notice PM or as a weekly control. The Lactobacillus eats it,the silicone is an additional PM control,and the soap is the surfactant.

 

[ganjherbsmoke]

come to Colorado i can hardly get my room above 20% doesnt seem to affect plants as far as i can tell i hear eagle20 and dutch master penetrator have some good results with pm tho

 

[guest2012y]

Eagle 20 MSDS link.....not something I'd smoke....may kill PM,but do you really want to puff herb that's been treated with this stuff? This is the organic soil forum...we don't roll with Eagle 20.
Read this:
http://www.golf-venture.com/msds/EAGLE633.pdf

 

[ganjherbsmoke]

lol if u wanna spray flowers be my guest but im pretty sure most people dont spray anything no matter what it is after a couple weeks of flower
veg only and this may be an organic thread but trust me
ur not gettin rid of ur pm with anything other than a near destruction concoction if its showing on the leaves its inside the plant already either eliminate it 100% the way you should or kill your crop unless u wanna risk dusting any non infected plants or smoking mold...

 

[guest2012y]

Can't get rid of PM if you live in an environment that has 3000 types floating around,even using filters. It's about management in organic gardening not expecting absolute control,and yes lactobacillus can be sprayed in flower with no noticeable decrease in smoke-ability. It's a micro organism....it's everywhere all the time. At the quanity diluted to water I find it hard to believe anyone would even notice the lactobacillus treatment. If you think that would bother you,wash it off before harvest,it's water soluble. People spray lactobacillus on plants anyway because it's beneficial to plant health.
Another reason to use silicone is that it builds strong cells,strong cells are more resistant to attack form PM and insects...using silicone PM can't get into the inner cells to set up camp so it attacks the surface cells where it tries to get a foothold to spore out. If you see white fuzz it has spored out and has released spores into your room.
You can clean the room after harvest,that helps...but if it's still getting sucked in,you're just chasing your tail in PM heavy areas.
Some types of PM are systemic,some plants are more resistant. In this case some of us are experimenting with neem seed meal in the soil mix,or soil drenches using neem oil and silicone. The jury is out on whether or not the oil or it's active compound can actually be absorbed by the roots to get it into the tissue of the plant.
Where I live everything is being attacked by PM..there is no starting over,just packing it up and moving to another environment or doing an organic control method..even in flower. PM doesn't care that you have flowers,so me and my organic pals will continue to use organic methods in flower.
Using silicone in every watering I have eliminated the systemic nature of some types in my garden,but it's still in the air and it's always trying to set up camp.
I'd by far rather smoke some miniscule concentration of leftover microlife residue than put anything that is known to cause cancer,etc. in my garden.
Again..this is the organic soil forum. There are other places to take the praise of chemical usage on this site.

 

[Zendo]

lol if u wanna spray flowers be my guest but im pretty sure most people dont spray anything no matter what it is after a couple weeks of flower
veg only and this may be an organic thread but trust me
ur not gettin rid of ur pm with anything other than a near destruction concoction if its showing on the leaves its inside the plant already either eliminate it 100% the way you should or kill your crop unless u wanna risk dusting any non infected plants or smoking mold...

This post was 100% correct , except for the beginning, middle, and end.

I've dealt with PM with foliar spray in flower, no problems, and no smoking mold,and without rolling with a 'near destruction concoction'.

I used a different method than above, but I assure you that in the future I will if needed..already saved recipe to file.

 

[bonjourbonjour]

Will you do not want to drop it soo low that you stress your plants. So if you can set your dehumidifier to 40% then that would be perfect keep it at a constant level.

Your going to have to kill the mildew first with fungicide. Depending how far in flower you are will determine the strength of the fungicide you buy. Take a few days of giving fungicide treatments untill all visible mildew is gone from the base of the plant from the under leaves right to the brand new growth tips.

If you can get your hands on a sulphur burner give some treatments of that. After killing all visible mildew and using the burner to disinfect the room make sure your dial in your temps.

Remember temp fluctuation from day and night also attributes to PM

Good Luck!

Posted in ": Can we please make a Sticky for Powdery Mildew, Bud Rot, etc."

 

[medthumb]

thanks for all the responses guys.

the funny thing is, i live in colorado. the humidity level outside is rarely above 30 %, but without my dehumidifer, my closet shoots above 60%. im just surprised that the PM is able to keep reproducing, even though im running the humidity extremely low (almost always less than 30%)

im running 3 plants with a 400 watt, aircooled with the exhaust running outside. i cant remember the size of my fan, but it should definitely be strong enough for a closet the size of mine.

ill give the milk spray a shot. i was hoping to be able to control it by limiting the humidity. i suppose though that there are still spores everywhere, regardless.

 

[Trillion]

Organic PM spray developed by me and CC..(with influence from Mad L.)
Per 1 gallon non-chlorinated water:
1/4 cup Lactobacillus culture (make it yourself)
1/4 cup Dyna-Gro silicone
A few drops Dr. Bronner's peppermint soap
Spray before lights go off if in flower,stinks like cheese,but goes away after a couple days...safe for flowers. Spray anytime you notice PM or as a weekly control. The Lactobacillus eats it,the silicone is an additional PM control,and the soap is the surfactant.

Why peppermint though! I've got the eucalyptus, gotta love dr Bronner's!

 

[guest2012y]

Why peppermint though! I've got the eucalyptus, gotta love dr Bronner's!

Because I had peppermint on hand and it worked...no other reason. I think in the next trip to the co-op I would opt for something else from the Dr Bronner line that was more gentle on the microbes.
It just worked so I stuck with it. Just a few drops per gallon.

 

[NUG-JUG]

come to Colorado i can hardly get my room above 20% doesnt seem to affect plants as far as i can tell

True that. I've only seen PM once here..It can't seem to take over in our dry air. I think low humidity affects yields, but improves resin content.

 

[supermanlives]

20 aint shit i hit 70. luckilly i got a semi resistant strain. for me increased airflow seems to keep it at a minimum. if you get pm at them percents you need a cleanup bigtime.

 

[milehighmedical]

.

 

[D.S. Toker. MD]

You know medthumb, im an outdoor grower and i cant really control any aspect of my enviroment. But for many years, ive studied and fought the terrible Pm disease. My first experience with it was years ago when we had 1500 plants in a large cornfield and the disease showed up in late july and within 30 days every plant was dead.

After all of the study and experience, i still only know a few things for sure. Ill tell you what I think i know.

Its my belief that once a plant is infected with the disease,the only sure fire cure is a systemic fungicide like eagle 20. Not a good option in my view. Sulphur can help but you have to be devoid of taste buds to be able to smoke the weed.

TEMPERATURE ... is the only factor that i have seen that can affect pm on the indoors. Temperatures below about 50 degrees,( ithink) have a significant impact on the disease. We placed a misted tray of 10,(6") small infected plants in an old fridge set at
39F degrees, with a couple of flourecents for 3 days and the disease clearly reacted negatively to the conditions and after 3 days, the "white" was a dead brown. The plants werent all that happy but a few days in the light and warmth and all was welll..In the winter, an indoor grower might use the cold, outdoor air to assist him.

RH. I dont know if humidity levels have much effect, except perhaps to facilitate the disease once its contracted. I have gone through a 3 week period with constant day temps above 95, with many days over 100 degrees with a rh of 90% by daylight that falls to about 70% during the heat of the day. Oppressive ,deblitating and mould grows on everything. No Pm.

Once the disease in in the room, air circlution is a negative which only serves to send the spores throughout the entire building of the grow room. Perhaps to even be sucked in by the buildings heating/cooling sytem waiting for the next grow..

Maybe i said something that you can add with your experiences and gain knowledge. Good luk to you.

 

[medthumb]

thanks once again to each who replied. a combination of everyone's experience is most helpful.

and i have been interested in how some strains are more resistant than others as well... my buddhas lil sis is constantly battling the pm, with new white spots showing up each day, even when running RH at less than 30 and keeping temps up in the mid to upper 80s. my gods gift, however, which is right next to the other one has hardly shown a single spot.