White mold on leaves

J

[email protected]

Member
Yes I have started to notice spots if this white mold on some leaves here and there. I have kept my humidity between 40 and 60% and temo don't go over 75. Dont know what else to do I have plenty of air circulation too.

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SnapsProvolone

SnapsProvolone

Well-Known Member
Ok here is the deal. Powdery mildew (pm) likes fluxuations between low and high humidity.

Often when lights go off temps drop and thus humidity rises. Bam you got pm.

Avoud by eliminating flux with adequate ventilation or space heater even.

Rid with serenade and sulfur vaporizer in large room or in a box just use serenade. There are other methods I have tried but the aforementioned actually work. Others were useful as tits on a nun.

Three percent rule applies, once 3 percent of your foliage is infected you are at a loss to repair.
 
SnapsProvolone

SnapsProvolone

Well-Known Member
Keep humidity between 45 - 55 %. Warm air holds more water so if you can't remove water you have option to heat air to drop relative humidity. remember that a dehumidifier works on the condensation principal so you will not get good results with cool air. They work best with air above 80 degrees Fahrenheit.
 
grasscropper

grasscropper

Well-Known Member
I too am having an issue with this. My set up is in the basement. I keep the house cool at night. So I figured this May have been the issue as I was watering when lights were due to turn off. This grow I have flipped my light cycle and lights are on all night, off all day. Now watering time is when lights come but I am still seeing this on some leaves. I have tried the baking soda and water method... Mix with water and spray the foliage. Apparently doesn't harm the buds. But I still see it or it's residue from the baking soda. Relative humidity is 35%. Maybe higher later in the cycle. May have to take the plants out and spray down the tent with bleach and water.
 
ButchyBoy

ButchyBoy

Well-Known Member
I tried the milk and water thing once. It left a residue similar to what you have and stunk up the room real bad. That looks uniform like it could be from your baking soda spray. Do you have any pictures showing spots of white?

I have battled PM in the past and my best results were using neem oil during veg. I installed a fan to force air into the room from outside instead of the room being under vacuum from the exhaust fan and drawing air from every little nook and cranny. Since upgrading the ventilation I have had zero issues with PM.

You should look at your ventilation ASAP!
 
grasscropper

grasscropper

Well-Known Member
chewberto said:
Exhaust the room, and oscillating fans with a dehumidifier should do it!
Click to expand...
My room is exhausted. And has a fan. Dehumidifier outside the tent. No room inside and I have always run it down there. Maybe a better fan but still have to take care of the plants now.
 
grasscropper

grasscropper

Well-Known Member
ButchyBoy said:
I tried the milk and water thing once. It left a residue similar to what you have and stunk up the room real bad. That looks uniform like it could be from your baking soda spray. Do you have any pictures showing spots of white?

I have battled PM in the past and my best results were using neem oil during veg. I installed a fan to force air into the room from outside instead of the room being under vacuum from the exhaust fan and drawing air from every little nook and cranny. Since upgrading the ventilation I have had zero issues with PM.

You should look at your ventilation ASAP!
Click to expand...
I have a fan going I and exhausting out. Plus a regular fan in the tent. I will post pics in a day or so.
 
grasscropper

grasscropper

Well-Known Member
[email protected] said:
Yes I have started to notice spots if this white mold on some leaves here and there. I have kept my humidity between 40 and 60% and temo don't go over 75. Dont know what else to do I have plenty of air circulation too.

Sent from my SGH-M919 using Rollitup mobile app
Click to expand...
Your pic doesn't look too bad tho. PM looks like there's a film of dirt or dust on the leaves and they need a wiping down.
 
facestabber

facestabber

Active Member
ButchyBoy said:
The potassium bicarbonate will damage the flowers, been there done that a few times.
Click to expand...

True, I've found that mixing it at quarter recommended strength beats back the mildew with minimal to no damage.

RH and circulation are the most important factors in fighting PM though. Until a grower addresses those issues he's pissing in the wind.
 
grasscropper

grasscropper

Well-Known Member
I opened up the tent tonight. Humidity is 34% when the lights came on. Last night say 3 hours in it wasn't much higher than that. It's cold here and dry cold. Running lights at night and during I have a dehu running in the basement. Hasn't been emptied since the change of weather. Sprayed them with plain water to rid the residue and left the tent open till they were dry. Added another big fan.
I did notice that spraying with the bicarbonate mix has made some of the hairs brown. I don't like doing it but am afraid I will lose these plants. Which would piss me off tremendously. Fuck fuck fuck! :wall:
 
ButchyBoy

ButchyBoy

Well-Known Member
grasscropper said:
I opened up the tent tonight. Humidity is 34% when the lights came on. Last night say 3 hours in it wasn't much higher than that. It's cold here and dry cold. Running lights at night and during I have a dehu running in the basement. Hasn't been emptied since the change of weather. Sprayed them with plain water to rid the residue and left the tent open till they were dry. Added another big fan.
I did notice that spraying with the bicarbonate mix has made some of the hairs brown. I don't like doing it but am afraid I will lose these plants. Which would piss me off tremendously. Fuck fuck fuck! :wall:
Click to expand...
Exactly... it will turn the hairs brown.

I have been in your situation many times. Summer is hell for me but winter is a blessing. During winter my humidity falls to between 20% and 35% and I have little to no mold issues. For me, Neem oil has worked the best. Milk/water makes a terrible funk in the room and did nothing for the PM. GreenCure (sodium bicarbonate) held off the PM for a short amount of time but jacks up flowers.

I keep increasing the air flow so that could be helping my issue. I currently have a 240 cfm exhausting the room and a 50cfm blowing fresh air from outside into the room along with two oscillating fans. Next month I am adding another 400cfm exhausting the room through a carbon filter.

How close are the girls to each other? Do you have air movement between the plants?
 
grasscropper

grasscropper

Well-Known Member
ButchyBoy said:
Exactly... it will turn the hairs brown.

I have been in your situation many times. Summer is hell for me but winter is a blessing. During winter my humidity falls to between 20% and 35% and I have little to no mold issues. For me, Neem oil has worked the best. Milk/water makes a terrible funk in the room and did nothing for the PM. GreenCure (sodium bicarbonate) held off the PM for a short amount of time but jacks up flowers.

I keep increasing the air flow so that could be helping my issue. I currently have a 240 cfm exhausting the room and a 50cfm blowing fresh air from outside into the room along with two oscillating fans. Next month I am adding another 400cfm exhausting the room through a carbon filter.

How close are the girls to each other? Do you have air movement between the plants?
Click to expand...
That's just it. They are in there tight. One of the ladies was in veg too long for the size of my flowering tent. Should have kept her as my mother and just kept taking clippings from her or flowered her alone. But we get greedy!! Humidity was 29% and temp 77 tonight. Windy In there with the additional fan and i have that placed low to get under the canopy. Watered when lights came on.
 
ButchyBoy

ButchyBoy

Well-Known Member
I had a problem with over crowding myself. Although I spotted some PM on a plant a day ago, I believe increasing the size of my room is what has cut down on it for me as there is less over crowding happening. I think the reason I have PM now is because I forgot to plug my heater back in and the temps dropped to 31.6 degrees over night which caused the humidity to jump up to 45% after the heater was plugged back in. The next day the humidity was back to 24% with a temp of 75.4 Degrees.

Good luck with your battle! It can be a tough one..
 
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