Neem oil did not work on my powdery mildew

[mad librettist]

well if microbes break it down, sure, neem oil is absorbed. Or rather, the nutrients in neem oil are cycled and the plant gets some.

but would the active ingredient enter the root using oil as a vehicle? this makes no sense to me. Roots drink via osmosis, not capillary action. If oil could get in, all sorts of stuff could get in.

surfer, got pics of that botrytis? Or detailed description? It is an IPM thread after all.

 

[ixnay007]

The best preventative medicine you can use against botrytis (and probably a host of other molds, etc) is aspirin (or if you prefer, a willow bark or small willow branch tea).. salicylic acid is what plants use to signal stress/predators/disease so the plant will be more defensive to begin with.. that plus silica should make a plant pretty resistant.

http://www.springerlink.com/content/k2182003n348814q/

http://www.plantea.com/plant-aspirin.htm

Aspirin has specific doses, willow water is not nearly as concentrated (unless you use a ton of branches)..

 

[Flying Goat]

Clackamas Coot - You are correct! I should have specified that we have higher temperatures & horrendous humidity down here in the South...

I see no leaf damage in my indoor garden, but I have not had issues with PM there in years... In the veggie garden, however, treatment with the 1 tablespoon is ineffective when used on squash or beans... Even so, it often required additional dosing with milk in a rotational fashion...

Fortunately, baking soda is cheap & I have a never-ending source of lovely goats' milk!

I do appreciate your clarifying that the high dose might harm plants in another area...

 

[sudsandbuds]

ive never heard of using neem oil for PM. i use one part skim milk and nine parts water with a couple drops of soap in the sprayer. always worked 100% for me. gotta spray em before or right after lights go off or on just make sure you dont burn em

 

[mad librettist]

neem is a pretty broad spectrum fungicide as far as I know.

 

[D.S. Toker. MD]

Gosh

Isnt it unfortunate that the insertion of fact into a discussion can create controversy? Oh well, here i go.

Folks, Powdery mildew is a fatal condition in cannabis. Not neem oil, not spectracide, not milk, not sulphur, no substance will save the plants if they become infested with Powdery Mildew. It is a death sentence in every case. Greencure does kill Powdery mildew and is the most effective product on the market for botryitis, but even though it will kill Pm, it cant prevent the death of the plant. The reason is given below.

There are many How-to grow guides that will confirm this assertion. Mel Franks books or Georges Cervantes video's give good examples of Pm and warn of its untreatable and fatal consequences.

People often confuse Downy Mildew with Powdery mildew and sometimes botryitis. Downy mildew is a white powder that appears on the leaves, spreads quickly but is harmless. The first sign of Powdery mildew is severe leaf yellowing and drop and days later the wilt of the branch. No disease is apparant on the plant at this time. Growers usually start applying a multitude of products such as pesticides or Neem but by the time one realizes the treatments arent working, every leaf has fallen off and total wilt occurs.. By the time "white" actually appears on the plant and you think this might be PM, the majority of the leaves have fallen off, infestation is rampant and death is imminent.. The Leaf drop is so fast and so severe that it creates a problem in itself. Even if you apply a product like Greencure that would kill the Pm, the plant has no leaves left and growth would be severly impacted.

Thank goodness Powdery mildew is quite rare. In years of growing outdoors ive only seen it twice but both times it killed every plant in the area. Ive never seen it indoors but i guess its certainly possible

 

[*mr.mike*]

I find that if you can control who's in the pots and on the plants, (besides the obvious temp and humidity) then most other problems never really develop.

Any bugs or mites are a bad thing. Even "beneficial" ones. They're walking all over the substrates, in and out of the immediate growing area. They can and do bring bad spores and other bits of bad crap all around.

I've observed mites eating pollen, and seen how they can explode during pollen production. Even if these mites only eat pollen, and not the plants, they make, and spread, a lot of garbage that upsets everything I try to strive for.

Just a general misting regime can disrupt a lot of microflora.

The biggest killer of plants is a mindset... the one that says "now that I've beat this pest, I can just sit back for a few weeks." It's always living in your house, unless it's on vacation. Because it IS coming back.

 

[mad librettist]

People often confuse Downy Mildew with Powdery mildew and sometimes botryitis. Downy mildew is a white powder that appears on the leaves, spreads quickly but is harmless. The first sign of Powdery mildew is severe leaf yellowing and drop and days later the wilt of the branch

Is there a citation in those books maybe? I can't even figure out which species of mildew infects cannabis, so I can't verify your claim. Further, every gardening site I can find mentions that PM is "easy to treat". While systemic fungicides are often mentioned, I find no mention of systemic infection. I have noticed what looks like systemic infection before, spreading all over the plant.

The first sign of Powdery mildew is severe leaf yellowing and drop and days later the wilt of the branch.

sorry, no. They call it powdery mildew for a reason. The first sign of PM is well known by any gardener. What you describe sounds more like a virus or trauma. Mildew reproduces by spores, which land on a leaf. If conditions are right, it germinates, spreads across the leaf, and makes new spores which moves around via watering or air movement.



The symptoms you describe though, yellowing leaves an all that, are most likely something else, not PM

even though it will kill Pm, it cant prevent the death of the plant.

I have rescued various plants of various species from moderate PM. On my squashes outside, I hardly bother as they seem to fight it off or live with it and still produce.

Any bugs or mites are a bad thing. Even "beneficial" ones. They're walking all over the substrates, in and out of the immediate growing area. They can and do bring bad spores and other bits of bad crap all around.

arthropods serve as "taxi cabs" for microbes. 99% of those microbes are good. In fact, the good guys compete with the bad guys. Remove the supply of diverse microbes and you have ... pathogenic dominance.

seriously, it's organic. We are supposed to be the ones who like nature.

 

[guest2012y]

Neem worked for me.....I wax my surfboard with it. (no...not really,but it worked on the plants and I have no further issues. There are thousands of varieties of "PM" like molds)

 

[Jim Rockford]

There are like over 10,000 strains of powdery mildew. I know way too much about it. One thing, and only one thing, has ever worked in 22 years for me. I found it in this post, read all the posts by MARK6699331 in this thread:
http://www.icmag.com/ic/showthread.php?t=43220&highlight=zone+penetrator
This was very intensive. I burned sulfer every 3rd day and spent the time and money to complete dunk my plants as he described. I thank Mark as much as anyone ever, I know how much powdery mildew sucks. Remember, when you see the white that is the end of the life cycle, your about 2 weeks two late.

 

[Fuel]

Spray neem in "interior/face down" of the leaf help; the texture of a fews indoor cannabis plants now is like "hermetic plastic" with the heavy nutrients schedules than big brand push.

 

[Albertine]

I think you are confusing downy with powdery, Dr. Powdery is quite common and visible, downy is the bad one, and not common.

 

[guyhowdy]

Gosh

Isnt it unfortunate that the insertion of fact into a discussion can create controversy? Oh well, here i go.

Folks, Powdery mildew is a fatal condition in cannabis. Not neem oil, not spectracide, not milk, not sulphur, no substance will save the plants if they become infested with Powdery Mildew. It is a death sentence in every case. Greencure does kill Powdery mildew and is the most effective product on the market for botryitis, but even though it will kill Pm, it cant prevent the death of the plant. The reason is given below.

There are many How-to grow guides that will confirm this assertion. Mel Franks books or Georges Cervantes video's give good examples of Pm and warn of its untreatable and fatal consequences.

People often confuse Downy Mildew with Powdery mildew and sometimes botryitis. Downy mildew is a white powder that appears on the leaves, spreads quickly but is harmless. The first sign of Powdery mildew is severe leaf yellowing and drop and days later the wilt of the branch. No disease is apparant on the plant at this time. Growers usually start applying a multitude of products such as pesticides or Neem but by the time one realizes the treatments arent working, every leaf has fallen off and total wilt occurs.. By the time "white" actually appears on the plant and you think this might be PM, the majority of the leaves have fallen off, infestation is rampant and death is imminent.. The Leaf drop is so fast and so severe that it creates a problem in itself. Even if you apply a product like Greencure that would kill the Pm, the plant has no leaves left and growth would be severly impacted.

Thank goodness Powdery mildew is quite rare. In years of growing outdoors ive only seen it twice but both times it killed every plant in the area. Ive never seen it indoors but i guess its certainly possible

I'm gonna go with Mad Lib on this one, if you've ever smoked or have seen buds that have PM on them...then you would know that PM isn't a death sentence and it can be passed on from a harvested plant straight into your lungs. I've heard that PM is systemic and is the herpes of the plant world(once you have it, you HAVE it.) What does this even mean?? If I take a clone from a plant that has been treated for PM, will the clone randomly pop up with PM for no reason?? In my personal experience, the first sign of PM is not severe leaf yellowing, but rather small patches of white powder that appear at first on top of healthy leaves. From the symptoms you describe, the plant would never even make it to harvest. How have I seen buds with PM on the tiny bud leaves? Your facts have got me mad confused, but after all folks isnt it unfortunate that the insertion of fact into a discussion can create controversy?

 

[guyhowdy]

If you wikipedia downy mildew, there is a side by side picture of downy mildew next to powdery mildew.

 

[ocean99]

I got this product called "serenade" at the first sign of PM, haven't seen leaf droop or mildew since the first application.

 

[D.S. Toker. MD]

Ill just restate the facts, thats all i can do

Pm is a fatal and devastating disease in Cannabis and by the time powdery mildew is observed on a plant that plant is as dead as a doornail without exception. .

http://www.icmag.com/ic/showthread.php?t=129670
Here's Chimera's take on it and his method is concurrent with conventional thought among professionals in my view that only highly toxic sytemics have any hope of effectiveness . I have doubts about Meltatox but please, please use great caution with these products. Never consume the treated plants. Only the next generations are safe

The first sign of Powdery Mildew in cannabis is severe leaf yellowing and then leaf drop, although occassionally, whole branch wilt is the first symptom followed quickly by entire plant wilt and death. Powdery Mildew Never presents itself as an opaque film until the plant is overwhelmed and death is near. The "white film" is the flowering part of the disease. The active disease spores are inside the plant,invisible and arent affected by any substance that isnt systemic in nature. The treatment and elimination of the white film on the surface of the leaves doesnt have any impact on the internal infection or the course of the disease. NONE. If you see the opaque film, youre done. Dead, dead, dead, dead without exception.


The grow is over folks.

 

[mad librettist]

thats's your citation?

ICmag is your citation?

 

[D.S. Toker. MD]

Chimera is my citation.

I conducted my research origially many years ago when i first encountered the disease and don't want to repeat it, but do some research on the work of Georges Cervantes, Mel Franks, Ed Rosenthal or any other cannabis researcher you want.

In fact, i would challenge anyone to present a statement by a respected breeder grower that would suggest that PM is a treatable disease. Its my view you will be unsuccessful.

 

[mad librettist]

chimera is not an authority sorry. I just asked him for citations, let's see what we get.

further, your other sources are not suitable primary sources. those are writers documenting the cultivation practices they see, not researchers.

you are trying to establish a provable fact. what constitutes a fact in your mind? If your sources are contradicted by your local extension, a textbook, mycologists everywhere, agriculture as a whole, etc... when do you begin to question your sources?

 

[D.S. Toker. MD]

You dont give any respect to the oldest most experieced members of the cannabis growing community? I believe the experience of many many grows results in a wisdom unabtainable through pure research.

Did you read his post?

Chimera, Cervantes and the others became researchers the first time they lost a crop to PM. We all read everything we could find on the disease and continue to do so today. The conclusions i have come to are a result of that research, combined with several battles with the disease.

My first "source" was the panic of a dying crop of mexican in the early 80's. Everything i have read has been consistent with my experience so i havent questioned its validity.