Powdery Mildew

[rafaeltoral]

Hello everyone. I am starting this thread to relate my personal experience with Powdery Mildew.

 

A little over a week ago I noticed what looked like a little patch of dust on a leaf of one of my plants.

It never got out of control, or spread to any bud, but in a matter of a week it had spread to all 7 plants in my tent.

I run a perpetual grow. This is my first time growing from clones. Up until now I have used seed. This is my first time seeing Powdery Mildew.

 

The causes are the following:

Infected clones brought into the garden

Inadequate air agitation inside the flowering tent

Humidity spikes after lights out up into the 60% range

Temperatures in the low 60's during lights off

 

At first I spot treated with neem. I added enough fans to make a tornado jealous. I got the humidity in check, it never goes above 45%.

I increased night time temperatures so they did not fall below 70. This kept everything under control.

I read quite a few threads and articles, pertaining to PM and cannabis, online. After educating myself I decided Greencure would be my best bet.

 

Greencure is a proprietary blend of potassium bicarbonate. Potassium Bicarbonate kills PM on contact, and leaves a residue that lasts for upto 2 weeks that prevents PM spores from germinating. Greencure can be used up until the last day of flowering. Unlike baking soda, which is Sodium Bicarbonate, Greencure does not need to be washed off.

 

I prepared a solution of 1 gallon distilled water to 1 tablespoon of Greencure. I shook it up really well, let it sit for twenty minutes, then shook it up really well again. I took all 7 plants, in their various stages of flowering, into the bathtub. I sprayed each plant very thoroughly. I got every nook and cranny, every surface area was coated.

 

The few spots of PM vanished. The plants looked very healthy, except most pistils turned brown. I probably should have not put the plants back under the HPS. It is recommended to spray directly prior to lights off, I believe this may be one reason why. Everything else was unaffected.

 

So far it has been three days and I have not seen a spot of mildew. The plants that had their pistils burned seem unaffected. New pistils have sprouted from new calyxes. I will continue to spray all of my plants, every week. I will not spray the last week of flowering, as I don't want any excess potassium affecting the flavor of my buds. I will probably try a slighly more dilute solution of Greencure next treatment, probably 1 teaspoon as most of the threads I have read seem to suggest.

 

I will continue to report my progress with the Greencure. I'm hoping it can get me through a few more cycles before I upgrade to a closed growing environment.

 

P.S. I understand Powdery Mildew is systemic and cannot be completely eradicated from an infected plant. I have read of something called Malatox that is really nasty and can, allegedly, sanitize a plant of a Powdery Mildew infection. However, my main goal is to simply keep the PM from rearing its ugly head at all. From much of what I read the Greencure will allow me to do this with minimal drawbacks. Its kind of like having herpes but never having an outbreak. Weed herpes.

Edited January 3, 2011 by rafaeltoral

[Grow Thread]

lol@weed herpes

 

you may want to look into a sulfur burner as well: http://www.4hydroponics.com/growroom/pest2.asp?ItemNo=sulfurVaporizer

[curegiver]

Where'd you buy Greencure? I can't find it locally.

[Brandan]

Here u go bro. I too had to deal with the mildew and this is how i got rid of it: http://michiganmedicalmarijuana.org/topic/21548-brandans-perpetual-grow/page__st__100

 

work fine for me, solved my PM problem.. let me know how it works for you..

[rafaeltoral]

I purchased GreenCure at Superior Growers Supply in Livonia. The trick, from what I understand, is to make sure all plant surfaces are coated when applying the GreenCure solution. Its kinda hard to pull that off if the plants are late in flowering. I had a couple that were at 5.5 weeks flowering. I took my time making sure I got inside the bud, and everywhere else for that matter.

 

Thanks for the tip on the Sulfur Burner. If I find the GreenCure to be insufficient I will try a sulfur burner.

However, I am in a 250 square foot apartment, and my grow tent is only 4x4, so I feel burning sulfur in this tiny apartment may not be ideal.

[rafaeltoral]

It has been a little over a week since I first applied greencure. I have seen no signs of PM since. Airflow inside the tent is great. Humidity has been between 35%-45%.

 

For my first application I used 1 tablespoon greencure per gallon of distilled water. This concentration pretty much turned all of my pistils brown. Since then new pistils have developed and the buds have continued to swell.

 

For this second application I used 1 teaspoon greencure per gallon of distilled. I took my time and sprayed every nook and cranny. Any uncovered surface is a place for PM to regain a foothold. It seems counterintuitive to soak a plant in it's 7th week of flowering, but apparently greencure protects againgst budrot, and other no-fun fungi. I sprayed before lights out. I took all 5 plants into the tub, sprayed 'em all down, then put them back into the dark tent. Also, I have been trying to line my watering schedule up with the greencure applications.

 

The plants look great today. I can't tell if any pistils were burned as they were mostly already brown.

I have 2 Purple Kush at 7 weeks flowering, 2 Magnum Champagne at 6 weeks, and 1 Aurora-Indica in vegetative.

[curegiver]

I mixed 1 tablespoon GreenCure in a gallon of RO water. Sprayed liberally on my vegging plants. I accidently went all the way down the line and sprayed my clones, too. That wasn't part of the plan.

 

The next day, I noticed the tips of my large vegging plants were burned a dark green almost black. Very little burn on the tips.

Some of the clones have a brownish color on the main shoots. I think I'm gonna transplant them now since they're rooted.

 

The other rooms will get a dosage of 1/2 tablespoon per gallon.

 

Had I seen your post I would have started off with 1/2 tablespoon!

[Royal Smoke]

lol@weed herpes

 

you may want to look into a sulfur burner as well: http://www.4hydropon...sulfurVaporizer

 

Here u go bro. I too had to deal with the mildew and this is how i got rid of it: http://michiganmedic...w/page__st__100

 

work fine for me, solved my PM problem.. let me know how it works for you..

 

I tried all kinds of things to get rid of my Powdery Mildew problem. Doing a Sulfur Burn is the way to go! I mean, I had a serious infestation (check out the pics).

 

You can put together a DIY Sulfur Burner like Brandan show's how. Only costs about $30 for parts, plus the Sulfur (2.5lbs for $16 - you only need a few tablespoons, so see if you can find a smaller amount)

 

Good Luck! It will most likely reappear unless you do a Sulfur burn, from my experience.

 

http://www.hydroponi...ery-mildew.html

Edited January 8, 2011 by Royal Smoke

[rafaeltoral]

I tried all kinds of things to get rid of my Powdery Mildew problem. Doing a Sulfur Burn is the way to go! I mean, I had a serious infestation (check out the pics).

 

You can put together a DIY Sulfur Burner like Brandan show's how. Only costs about $30 for parts, plus the Sulfur (2.5lbs for $16 - you only need a few tablespoons, so see if you can find a smaller amount)

 

Good Luck! It will most likely reappear unless you do a Sulfur burn, from my experience.

 

http://www.hydroponi...ery-mildew.html

 

If the GreenCure fails I will be sure to try Sulfur. I don't think it is going to be necessary though.

It is important to remember that potassium bicarb and sodium bicarb are two different animals. Looking over your grow, from the link you provided, I noticed you never gave potassium bicarbonate a try. It's been nine days and I have not seen any PM. I spray once per week so I don't see how it is going to come back.

[Royal Smoke]

If the GreenCure fails I will be sure to try Sulfur. I don't think it is going to be necessary though.

It is important to remember that potassium bicarb and sodium bicarb are two different animals. Looking over your grow, from the link you provided, I noticed you never gave potassium bicarbonate a try. It's been nine days and I have not seen any PM. I spray once per week so I don't see how it is going to come back.

 

I thought the Serenade Spray was a potassium bicarbonate spray, but after reviewing my findings on Google, I guess it's not. I don't recommend anyone using this spray. It fried my plants!

 

 

 

Looks like you've found another 'cure'. Keep us posted. I may have to add that to my site also!

[AmishRnot4ganja]

I thought the Serenade Spray was a potassium bicarbonate spray, but after reviewing my findings on Google, I guess it's not. I don't recommend anyone using this spray. It fried my plants!

 

 

 

Looks like you've found another 'cure'. Keep us posted. I may have to add that to my site also!

 

I have used Serenade a number of times with no ill effects whatsoever (except for the ungodly smell). Last week i tried a 10% milk solution. It appears to work every bit as well as Serenade. I am going to hang my sulphur burner today and give that a try next.

[Petyr]

In the future use a 1/2 tablespoon of Greencure in the gallon of water and you won't burn the pistils. It will still take care of the PM. It is good stuff, I've used it for outdoor plants in the past and it definately does the job.

 

+1 for the bud rot prevention too. I was mainly using it for that and it worked.

Edited January 10, 2011 by Petyr

[Dlo]

Green cure kicks :jipo: . If you dont want to, or cant do the sulfur burn its the best thing out there. IMO

[curegiver]

It has been 7 days or more. No more PM. I didn't even change temps or airflow in one of the rooms. GreenCure is fantastic!

 

Use 1/2 tablespoon per gallon.

[rafaeltoral]

Today I applied my third application of Greencure. Since the first application I have not seen any signs of PM, and I look hard.

 

This time I decided to go with 1/2 teaspoon per gallon, as has been recommended by a few others. If you use a higher concentration the pistils can get burnt, though it does not seem to have any effect other than appearance.

 

It has been over two weeks and no PM to be seen.

 

I think it is safe to call Greencure a success.

[Petyr]

Teaspoon or Tablespoon for the last application? Just so people don't get confused...

[rafaeltoral]

Teaspoon or Tablespoon for the last application? Just so people don't get confused...

 

I went down to 1/2 teaspoon. I harvest these plants in about a week, so I wanted to use as little as possible.

The problem with higher concentrations is it burns the pistils, if you put them back under the lights before they have had a few hours to dry the leaves can burn too.

 

I line watering up with applying Greencure. I will water when lights come on, then right before lights go off I apply Greencure.

Edited January 15, 2011 by rafaeltoral

[rafaeltoral]

I harvested a little over a week ago. Today I tried a couple small test buds. First off this Purple Kush is pretty darn potent. It smells like a rag soaked in gasoline. There was no noticeable effect from the Greencure, other than the really dark, blackish pistils.

 

I am hoping I can make this stuff last long enough to see what a two month cure does for flavor and aroma. Being only a week from harvest it still tastes pretty "hot".

 

I had dropped down to a 1/2 teaspoon since I was close to harvest. I have since been treating my vegetative plants with 1 teaspoon per gallon, applied weekly.

 

I have not seen a spot of PM since I first used Greencure.

Edited January 28, 2011 by rafaeltoral

[engineered_excellence]

I offered to watch a mother plant for a friend who is moving, they appeared free of all bugs and diseases. After a couple days in my veg room the mother started to develop a little powdery mildew, I took it out of the veg room and placed her in quarantine.. Is there a pretty good chance the rest of MY plants in veg will get the mildew? Should I just get some GreenCure to be safe.. I keep a super clean and dry room, I would rather be safe than sorry.

[Royal Smoke]

I offered to watch a mother plant for a friend who is moving, they appeared free of all bugs and diseases. After a couple days in my veg room the mother started to develop a little powdery mildew, I took it out of the veg room and placed her in quarantine.. Is there a pretty good chance the rest of MY plants in veg will get the mildew? Should I just get some GreenCure to be safe.. I keep a super clean and dry room, I would rather be safe than sorry.

 

Yeah, I'd do something. Better safe than sorry! You don't want to lose your whole crop I take it?

[engineered_excellence]

Yeah, I'd do something. Better safe than sorry! You don't want to lose your whole crop I take it?

 

 

Fortunately this plant came no where near my flower room, and so far no white on my plants in Veg... Is powdery mildew a complete crop ruiner? I'd imagine it would do more damage to plants in flower.. Also, I talked to someone else, and they told me not to worry because most likely what I am seeing is a result of a change in environment for the plant and it should only affect that one mother plant unless my plants got stressed somehow... is this true?

[Royal Smoke]

Fortunately this plant came no where near my flower room, and so far no white on my plants in Veg... Is powdery mildew a complete crop ruiner? I'd imagine it would do more damage to plants in flower.. Also, I talked to someone else, and they told me not to worry because most likely what I am seeing is a result of a change in environment for the plant and it should only affect that one mother plant unless my plants got stressed somehow... is this true?

 

It's a crop destroyer if it's in the Flower room. You can successful reveg the plants and battle the powdery mildew in veg and then return them to flower, like I did, but I wouldn't recommend it. It's a big pain and if I could do it over again, I would have just tossed the plants.

 

It's manageable in veg, but it can get overwhelming by spreading quickly (see my blog to see a pretty bad outbreak).

 

Also, I talked to someone else, and they told me not to worry because most likely what I am seeing is a result of a change in environment for the plant and it should only affect that one mother plant unless my plants got stressed somehow... is this true?

 

Another possibility is that it already had a tiny bit on it before you took it in and then it became more apparent. Change in environment can cause powdery mildew too though. Normally, if there is not enough air circulation you can develop it (like I did, doh! turned the fan off). Also huge temperature drops between light and dark hours can lead to the pm.

 

PM is very spreadable, catchy, contagious, whatever you want to call it, to the plants around it. If you see it one plant, chances are it's probably already spread to another plant, unless you caught it super quick. So, what your friend was saying about it only affecting that one mother plant doesn't really make sense to me.

 

http://www.hydroponicsupersonic.com/powdery-mildew.html

[AbominableDro-Man]

Just to let folks know, I've heard from the local growshop that Greencure will drop your plants' PH. <----This theory, however, is unconfirmed by me. 

Edited September 6, 2014 by AbominableDro-Man

[GanjaWarrior]

powdery mildew is not systemic accourding to the horticultre experts. not the hydro shop guys but the guys with degrees. a sulphor burner is key. a few years ago michigan saw a bad outbreak of it. i used the burner and got a dehumidifier.... not a spot in years mow. still running most of thos planst , always take clones before i flower. no pm .  but really ask the science guys. pot growers are the only ones that think its systemic. change the enviroment, give them a ph they cant handle its all done and over with.

[GanjaWarrior]

Just to let folks know, I've heard from the local growshop that Greencure will drop your plants' PH. <----This theory, however, is unconfirmed by me. 

i believe you are correct, the drop in ph is what kills the pm