PM keeps coming back, anyone ever win this battle?

K

kdt15

Active Member
Did a large amount of plants per 4x4 (~30) and combatted PM for multiple grows and they keep resurfacing. What's the way to get rid of this? Already do sulfur and inspections each day. dont have a dehu though, any suggestions would be great
 
thumper60

thumper60

Well-Known Member
kdt15 said:
Did a large amount of plants per 4x4 (~30) and combatted PM for multiple grows and they keep resurfacing. What's the way to get rid of this? Already do sulfur and inspections each day. dont have a dehu though, any suggestions would be great
Click to expand...
pretty simple get a dehuy
 
gwheels

gwheels

Well-Known Member
In addition you may need to switch out your filtration. PM can live all over the place.
But if you keep your RH 60 and below (i think that is the number you have to search it) PM can not thrive.

And lots of air movement. Lots of fans all over the 4 x 4 at variable heights.

I had PM once but it was a jungle in the 4 x 4. Now i defoliate to give them more room, keep the RH lower and place fans in better places within the tent
 
P

p0opstlnksal0t

Well-Known Member
Defoliation techniques for better air movement through the plant. I'm not sold on yields increasing due to defoliation it possibly even decreases my yields but I don't see any mildew or mold ever a more now that I defoliate and I have massive air movement. Humidity should be based on VPD alone. During veg I operate in the ideal zone of VPD at my temperature which is typically 65 to 70% humidity at 78 degrees during flower I drop it down slightly to 55 to 60% humidity
 
Rob Roy

Rob Roy

Well-Known Member
Something to ponder...

Two paths you could go down. Either one might make sense depending on your short term or long term goals.

Attempt to remediate while continuing your grow.
Powdery mildew can be forced into remission, but it lingers (it's a sneaky fucker) and can be difficult to eradicate on the fly without tainting your flowers. Can you live with that?

Others seek to get rid of it entirely and start over with a sparkly clean grow area and the right infrastructure set up to create a less mold friendly grow environment. Can you live with the down time?
 
StareCase

StareCase

Well-Known Member
Mold and mildew can develop if there is no air movement and venting during lights off - which was what I did with my previous grow. BAD FORM!!

The leaves transpire during lights out and that air needs to be extracted. This past grow, I left the fans and venting going 7/24 - no mold or mildew.
 
K

kdt15

Active Member
Rob Roy said:
Something to ponder...

Two paths you could go down. Either one might make sense depending on your short term or long term goals.

Attempt to remediate while continuing your grow.
Powdery mildew can be forced into remission, but it lingers (it's a sneaky fucker) and can be difficult to eradicate on the fly without tainting your flowers. Can you live with that?

Others seek to get rid of it entirely and start over with a sparkly clean grow area and the right infrastructure set up to create a less mold friendly grow environment. Can you live with the down time?
Click to expand...
for ridding it entirely? do you have a general suggestion on what things need to be done to remove it?
 
K

kdt15

Active Member
p0opstlnksal0t said:
Defoliation techniques for better air movement through the plant. I'm not sold on yields increasing due to defoliation it possibly even decreases my yields but I don't see any mildew or mold ever a more now that I defoliate and I have massive air movement. Humidity should be based on VPD alone. During veg I operate in the ideal zone of VPD at my temperature which is typically 65 to 70% humidity at 78 degrees during flower I drop it down slightly to 55 to 60% humidity
Click to expand...
what is the vpd stuff you mentioned?
 
curious2garden

curious2garden

Well-Known Mod
Staff member
kdt15 said:
Did a large amount of plants per 4x4 (~30) and combatted PM for multiple grows and they keep resurfacing. What's the way to get rid of this? Already do sulfur and inspections each day. dont have a dehu though, any suggestions would be great
Click to expand...
You need to find out what your RH is and deal with that
kdt15 said:
for ridding it entirely? do you have a general suggestion on what things need to be done to remove it?
Click to expand...
Take your affected room down. Dry it out, ventilate it and bleach every surface. I left mine down for 6 weeks. When you come back online make sure you keep your RH low. My PM was from a clone that had systemic powdery mildew as my RH is rarely over 10%, I'm in the Mojave desert. For systemic PM I used Regalia that allowed me to finish the strain cleanly. But then the room had to come down before my room became innoculated with it.
 
Temporal

Temporal

Active Member
Yeah, you definitely need a thermometer/hygrometer if you don't already have one. Really, best to have multiple, they're cheap, no reason to not have one. My veg area is right next to my flower tent, so I have to be careful. But yeah, my RH tends to hover around 40%. It gets up to 75% ever so often when I water, but that's okay as long as it's not a prolonged time in my experience. Did you say you grew a large number of plants in that 4x4? 30 plants? What size? I bet if you had em crammed in there, then that's part of your problem. You need a little air in between em. Unless you have a decent enough fan or something, but I'm a new grower myself, and am the opposite of an expert in growing cannabis, lol. This below is what I got going in my 4x4. There were more, but had to toss some due to mites of some sort. Never was able to definitively figure out what they were, but yeah, I feel your pain.
IMG_20190103_150913.jpg
 
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p0opstlnksal0t

Well-Known Member
PM is not systemic I hear that on here a lot.


Getting airflow between the buds and branches is of the utmost importance but not leaf damaging force wind. Constant moving airflow around and through the canopy.
 
Rob Roy

Rob Roy

Well-Known Member
kdt15 said:
for ridding it entirely? do you have a general suggestion on what things need to be done to remove it?
Click to expand...

Clean every surface in the grow area, walls, floor, ceiling, light fixtures, fans and fan blades etc. Then do it again. I use vinegar based spray cleaners myself, cheap and effective.

Toss any suspected powdery mildew spore hidy spot items, old soil, cleaning rags, spore infested grow tents, etc. I like vinegar based cleaners for cleaning surfaces and sometimes soapy water and a giant car washing sponge for panda paper walls .

When everything is super clean, put in environmental controls so that powdery mildew knows you mean business. You could probably find some good info on that topic posted in threads here.

Begin again with new seeds. Hopefully pm resistant strains. I'm a fan of neem or sulfur based sprays while the plants are in veg. Bugs don't like either one, get two birds stoned at once!

Be picky about what comes into or close to your grow area. For instance, if you had house plants that were outside in the summer and have been brought in for winter expect mites, aphids and / or mold as possibly hitching a ride. If you harvested outdoor weed and hung it to dry where any mold spores could blow into your indoor grow etc.

Research and read about others success stories and tailor them to your grow. Don't give up. Good luck.
 
thumper60

thumper60

Well-Known Member
p0opstlnksal0t said:
Defoliation techniques for better air movement through the plant. I'm not sold on yields increasing due to defoliation it possibly even decreases my yields but I don't see any mildew or mold ever a more now that I defoliate and I have massive air movement. Humidity should be based on VPD alone. During veg I operate in the ideal zone of VPD at my temperature which is typically 65 to 70% humidity at 78 degrees during flower I drop it down slightly to 55 to 60% humidity
Click to expand...
yikes!u run a lot higher than I would dare nothing over 50 ever!! for me
 
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