powder mildew? help from smart growers?

[organicmedicine]

Hi guys,

new here - I have some clones that I just received that have a bluish-gray staining on some of their leaves. is this powder mildew? or is it potentially some type of treatment that the cloner sprayed on there early on?

any help with this would help - pics below

[khyberkitsune]

Yea, that looks like PM to me. :(

Try spraying a mixture of 10% milk to 90% water. Do this weekly.

[stra8outtaWeed]

SM-90.....will take care of that....about $20 for quart....follow the foliar directions and it will stop PM and any molds you may have :thumbsup:

[copobo]

throw them away!

there is no organic cure.

[khyberkitsune]

throw them away!

there is no organic cure.

Milk has worked just fine for me. It's used in the California vineyards.

I'd trust a bunch of people that comprise a MAJOR part of California's economy and a fair share of the world's wine supply.

[copobo]

hey, whatever works. I guess I just want the stuff *gone* and don't want to be spraying anything on my buds weekly. If you want to keep spraying every 4 -7 days, neem and Serenade are both organic choices for temporary control.

Alot of talk about Eagle 20 these days, too. It's a non-organic people are using during veg only...

[Weekend]

if they are just clones & nothing special, trash them & get some new. if you were on day 50 of flower it would be a different story.

[HarvestHouse]

eagle-20 works very well. you will not have a PM problem after it's use. It's a much better choice than infecting some one with a compromised immune system with PM or the over use of products that don't truly work.

[HarvestHouse]

Also consider a product called Oxidate for PM during flower or simply use water adjusted to a pH of 10 using common pH UP and spray daily until it's gone.


it works.

[funkfingers]

I wouldn't mess with clones that came with pm pitch them..The idea is to never introduce pests/diseases into your grow..It will make your life easier in the long run.

[SoCoMMJ]

Also consider a product called Oxidate for PM during flower or simply use water adjusted to a pH of 10 using common pH UP and spray daily until it's gone.


it works.

Or if you wanted to use a commercial product that raises the PH and includes a nice sticker spreader...
GreenCure (http://www.megagro.com/greencure.htm)

Potassium Bicarbonate. I used it at 1/2 strength and it works fine.
hit everything in the room.

There is a PM thread somewhere on here that talks about it

[organicmedicine]

thanks guys this has been helpful - I'll try those options. someone told me that I might have tobacco mosaic virus or spider mites so looks like I'll have to learn more about all three afflictions! :)

[SpaceNeedle]

All the advice given has been very good. Nobody has however mentioned what the cause is, and I feel everyone should know, that generally it is caused by too high a relative humidity. No matter what you end up using to get rid of the powdery mildew, keep as low a humidity as you can, because the stuff thrives in 60% and high humidity.

for what its worth,

sn

[khyberkitsune]

All the advice given has been very good. Nobody has however mentioned what the cause is, and I feel everyone should know, that generally it is caused by too high a relative humidity. No matter what you end up using to get rid of the powdery mildew, keep as low a humidity as you can, because the stuff thrives in 60% and high humidity.

for what its worth,

sn

I don't have any problems getting PM in 10% RH in SoCal. Mildew thrives in low-light conditions more than high-humidity.

[Weezard]

I don't have any problems getting PM in 10% RH in SoCal. Mildew thrives in low-light conditions more than high-humidity.

I don't know that to be a fact, sir.

Got a strain here that gets PM when da buds swell up.
More correctly, they get PM whenever, and it "blooms" when they swell.
Got more light and ventilation than you can shake a stick at here, (Kona Coast).
Night time temps are high 60s, but the humidity can be fierce at times.
Got another strain, growing in the same cage that never shows PM.

Jus' a few more facts to mull.
Draw your own conclusions.

Aloha,
Weezard

[copobo]

ideal growing conditions for pm are temps below 70 and rh above 60. Big temp drops from day to night will cause dew and promote PM growth.

BUT, once you have it, those thresholds are out the window. Taking RH down to <40 and having temps >80F help allot. You'll want to be pushing some CO2 if you are going up to that level with the temps (tops at 85F w/1500ppm)

Weezard - is it a strain (different seeds, distinctly different grows), or cuts from the same plant? If cuts off the same plant, you may be spreading a latent infection from the mother plant - use some eagle 20 and break the chain if you need to save genetics. Certain strains are more prone to PM than others - strains with tons of foliage like blueberry are more susceptible. If this is the case, and you are having big temp drops or nighttime temps of below 70, it's important that you prune a bunch and/or shake the plants daily to release water trapped between leaves.

Try it. Go out and grab your tree by the stalk and shake. Does water fall when the plant otherwise appears dry? If so, you need to prune.

PM is a mutha.

[Weezard]

ideal growing conditions for pm are temps below 70 and rh above 60. Big temp drops from day to night will cause dew and promote PM growth.

BUT, once you have it, those thresholds are out the window. Taking RH down to <40 and having temps >80F help allot. You'll want to be pushing some CO2 if you are going up to that level with the temps (tops at 85F w/1500ppm)

Weezard - is it a strain (different seeds, distinctly different grows),

Different strains..

or cuts from the same plant? If cuts off the same plant, you may be spreading a latent infection from the mother plant - use some eagle 20 and break the chain if you need to save genetics. Certain strains are more prone to PM than others - strains with tons of foliage like blueberry are more susceptible.

Oddly enough the G13-Blueberry has no PM problems.
The lemon-skunks were ravaged, and I only managed to save some tops from HI Homie-III by harvesting early.:(

If this is the case, and you are having big temp drops or nighttime temps of below 70, it's important that you prune a bunch and/or shake the plants daily to release water trapped between leaves.

Runs between 82F. by day and 68F. by night this time of year and we seldom hit our dew point.
And they really are not that dense. Fairly open, and I have them roofed so the don't even see rain.

Try it. Go out and grab your tree by the stalk and shake. Does water fall when the plant otherwise appears dry? If so, you need to prune.

Nope, but it does annoy the whitefly.:D
It's their "nectar" that supplies a landing spot for drifting spores.


PM is a mutha.

Indeed! It's rampant on da islands.
I've read reams from all sources and they all agree that once infected, the outlook is grim.
('druther risk smokin' some PM than some of the stuff used to kill it.)
It looks like my only option is to breed my own PM resistant strain here.
I've got ahold of some Gainsville Green seeds that survived in Florida and want to cross them with the blueberry that grows so well here.
Any suggestions on breeding stock?

Aloha, and Mahalo
Weezard

[copobo]

if you are gonna smoke it, you can certainly wash it before drying/curing. PM does wash off.

it is a mutha!

I would go with what works for you in your area. the sativas seems to be more resistant to me. if the bb-g13's hold up. do more of that and drop out the ones prone to mold.

[khyberkitsune]

I don't know that to be a fact, sir.

Got a strain here that gets PM when da buds swell up.
More correctly, they get PM whenever, and it "blooms" when they swell.
Got more light and ventilation than you can shake a stick at here, (Kona Coast).
Night time temps are high 60s, but the humidity can be fierce at times.
Got another strain, growing in the same cage that never shows PM.

Jus' a few more facts to mull.
Draw your own conclusions.

Aloha,
Weezard

Noted. I've personally seen PM attack many of my landscaping clients out here in the high desert, even at sub-20 RH.

[khyberkitsune]

if you are gonna smoke it, you can certainly wash it before drying/curing. PM does wash off.

it is a mutha!

I would go with what works for you in your area. the sativas seems to be more resistant to me. if the bb-g13's hold up. do more of that and drop out the ones prone to mold.

PM permeates the entire plant, from leaf to stem, at least in the decorative flowering plants I planted last year over in southern Los Angeles for a hair salon.

Took about a week and PM all over the place.

[funkfingers]

Powdery mildew is systemic, so once it's visible the whole plant has it.. IMHO not even worth trying to salvage these plants unless they're irreplaceable..:rastasmoke:

[Weezard]

Powdery mildew is systemic, so once it's visible the whole plant has it.. IMHO not even worth trying to salvage these plants unless they're irreplaceable..:rastasmoke:

Sad to say, I agree.
Most of it went into the bubblehash bag.
You can wash off the PM bloom, but the actual infection goes allaway to the bone.:(
There are systemic poisons that will kill PM, but I'm not keen to smoke them either.
At least the hash extraction removes most of water soluable component.

Thanks for the input, guys.

Aloh,
Weeze

[Ebbandflowian]

So what would you guys reccomend doing to prevent pm from starting in the first place???

[copobo]

1 application of eagle 20 when you are doing or bringing in the cutting, and one application 1 week into flower. You'll never see the stuff again.

[blazetbone]

Dutch master zone and dutch master penetrator(now called Saturator) knocked out PM for me.

There is a thread on the International Cannagraphic forum that details the dosasge, application etc., and it worked very well for me. The milk seemed to provide a little relief but didn't knock it out like the Dutch master did. .

I think I only applied twice in early veg and now they are almost 7 weeks into flower and looking crusty! No more PM...don't get clones from Broadway Wellness! They even have a disclaimer on the wall now saying that many of their mothers are 20 years old(BS) and the PM is a possiblity with their clones.

Eagle works very well also, my buddy used this, but I think the Dutch Master isn't a pesticide like the Eagle.

[copobo]

http://boards.cannabis.com/search.php?searchid=168579

[Ned Grown]

Oxidate or Water pH'd to a value of 10 for PM during flowering. Eagle-20 or preferably Rubigan prior to bud set.

[denverbear]

we use eagle 2 and it really works...you can find it on e-bay cheaper

[Ned Grown]

Denver Bear-----> Rubigan was made for consumables. Eagle -20 was made for turf and ornamentals. Just an FYI.

[denverbear]

Denver Bear-----> Rubigan was made for consumables. Eagle -20 was made for turf and ornamentals. Just an FYI.

on the bottle of eagle there where instructions for using on vegtibles etc...just diluted more I believe..we where told about this product from at least 2 dispensarys and have had no problems using it.

[Ned Grown]

Eagle�® 20EW (http://www.dowagro.com/turf/prod/eagle.htm) link to product website

cut and past


Features

Convenient, liquid formulation
Prevents/treats dollar spot, anthracnose, summer patch, brown patch, powdery mildew, rust and scab
Available in two convenient sizes — one-gallon jugs and one-pint containers
Systemic protectant
For use on golf course fairways, roughs, tees and greens, commercial and residential stone fruit trees, apple trees and grapes, and other landscape ornamentals
For use on ornamentals such as chrysanthemums, daylilies, poinsettias and roses in nurseries, landscapes and greenhouses
Best control of labeled diseases is achieved when Eagle® 20EW is applied on a seven- to 10-day application schedule

[Ned Grown]

the point being, there are more suitable systemic fungicides for our application.

[realrockmama]

powdery mildew is white and looks powdery. cut the stem if its powdery mildew the inside of the stem will be white instead of green.

[realrockmama]

if you can stand the smell of neem oil go for it, it makes me gag

[sittingone]

Powdery mildew is HERPES for plants. It will not go away. You may get it to hide for a while, but it is there.

So, if you are going to clone those plants or ever bring other plants into that grow area they will all be affected as well. I shut down for 6 months to make sure I got rid of PM after dealing with it for many months. All fans and walls and such should be disinfected as well.

And making the analogy to the wine industry is silly. The grapes are not getting infected, the plant material is. Fruit is still fine. With Herb, the infected part is the good part and it is just not worth it! I get PM outdoors on my Lilacs, cukes, and squash and they are all fine. Again, because the fruit is fine, the plant material is suffering.

I would get some seeds or some clones from a more trusted source.

Good luck
sittingone

[MedicalMike]

I used to have PM bad. I dusted the preflower plants with sulpher and have not seen it again in years. Preflower only though or you get sulpher tasting medicine. Just my 2 cents.

[hippiebilly]

hey, whatever works. I guess I just want the stuff *gone* and don't want to be spraying anything on my buds weekly. If you want to keep spraying every 4 -7 days, neem and Serenade are both organic choices for temporary control.

Alot of talk about Eagle 20 these days, too. It's a non-organic people are using during veg only...
I tried Serenade a couple weeks ago. It killed the mold but... also killed the 2-plants I used it on. It was my own fault... after researching using Serenade further... I discovered that most folks recommend adding 50% more water to the "ready mixed" Serenade. I figured I would hollar' so someone else doesn't make the same mistake. Since then... we sprayed the whole room real good before we moved more babies in. We waited a week and went over our 8x16' rom with a fine tooth comb... no sign of any more mold so... new babies are enjoying their new "mold-free" home.