mysterious and destructive stem disease.

i am having a problem with what i now believe to be some form of severe stem disease. possibly a fungus. i actually believed that the problem was a rat or a squirrel, that had attacked some larger plants, as the damage was completely physical, in that it appeared as though a rat had sharpened his claws on the plant stems (at the base only).
now that i have some small new babes, it is OBVIOUS that this is a stem disease. very likely some sort of fungus. the symtoms as they appear now are as follows:

white powdery appearance at base of plant.
stems have become brittle and woody (not mushy)
there appear to be small, tough and hard, burls or spurs or knuckles or something, at the base of some of the plants.

later, as i stated earlier, the stems have chunks literally falling off, but in dry strands, that do look as if they have been scratched of by some sort of animal.

i cannot stress how important it is to me to take care of this problem immediately. at this time i have sprayed them with a fungicide from ortho, called rose pride. also, i have added food grade hydrogen peroxide to the resivoirs (1 ml to 20 gallons).

if anyone has ANY advice or experience, i would really appreciate it. thanks in advance to everyone...

- mu

also, i should add, that the plants have always had the appearance of good health. the flowers however were severely diminished last time.

whats the humidity in there?

I have burley little growths, at seems normal, but does this fit you: Zinc Toxicity:
Excess Zinc is extremely toxic and will cause rapid death. Excess zinc interferes with iron causing chlorosis from iron deficiency. Excess will cause sensitive plants to become chlorotic.

IMMOBILE ELEMENTS
Immobile elements will show their first symptoms on younger leaves and progress to the whole plant.

Sulphur (S)
Sulfate is involved in protein synthesis and is part of the amino acids, cystine and thiamine, which are the building blocks of proteins. It is active in the structure and metabolism in the plant. It is essential for respiration and the synthesis and breakdown of fatty acids.

Sulphur (S) deficiency:
The initial symptoms are the yellowing of the entire leaf including veins usually starting with the younger leaves. Leaf tips may yellow and curl downward. Sulfur deficiencies are light green fruit or younger leaves with a lack of succulence. Elongated roots and woody stem. Although it's hard to see in figure 19, the upper stems of this plant are purple. Although many varieties of cannabis do get purplish stems, the trait generally extends the entire length of the plant's stem, and not just near the top as in this specimen.

Taken from Grow Marijuana FAQ, Cannabis cultivation - marijuana growing tips & photos
Another helpful guide: International Cannagraphic Magazine Forums - The Complete guide to Sick Plants,pH, and Pest troubles!
:jointsmile:Bree

thank you for your speedy reply. i do not believe the symptoms match zinc toxicity, and i do not believe it is a sulphur issue. there is absolutely no visible sign of ill health on the leaves, as would be indicated as a symptom of both of these problems. i appreciate any additional input, and i will continue to research zinc toxicity. it appears to be a stem specific attack.

Quote:

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Originally Posted by invision

whats the humidity in there?

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75 degrees and 50% humidity max. usually closer to 35%.

ANY PICS?

Yes, I'd love to see!

Hi, if your plant stems are hard and woody then you can eliminate 95% of diseases. You're using hydro., is the plant root systems o.k. ? does the res. smell ? If yes, you have pythium, or root rot. If your roots are healthy, stems hard then yes, maybe a rodent or cat has decided to sharpen their claws on your babies. White powder normally indicates powdery mildew, but you have no obvious fungus attack. Maybe its just debris from the attack ? Don't forget that if your stems have suffered physical injury, then the healing process will harden stems up. You refer to knuckles at the plant base. This could be entirely normal, or the plant has been bent over and damaged, and the knuckle is the result of stem healing.
In the absence of any other symptoms, I would simply use an anti-fungal preparation to avoid the damaged stems picking up disease. You could also bind the stems with string, cloth or similar to help them heal, if the injury is bad.

i am sorry, i have not been totally clear. last round, i had the same damagae, and i THOUGHT they had been attacked by a rodent. now that i have fresh new babes (less than two weeks old) i can see similar damage starting already on the fresh stems. this is NOT a result of a physical attack, though the appearance is similar. i will do my best to upload some photos tonight.
there is no foul smell. root development is normal, and, honestly, no other indications of ill health. it is completely mysterious to me. i am intimate with powdery mildew, and this is not it. i am at a loss. again, i will do my best to get some photos up tonight, and again, thank you all for your participation in my salvation.

- mu

here are some photos of a damaged stem from last round.

- mu

tinkyattic
Registered+
Join Date: Nov-15-2005
Posts: 3,796


Quote:
Originally Posted by mutigen
stems have become brittle and woody (not mushy)
there appear to be small, tough and hard, burls or spurs or knuckles or something, at the base of some of the plants. later, as i stated earlier, the stems have chunks literally falling off, but in dry strands, that do look as if they have been scratched of by some sort of animal.

Cannabis plants DO grow a bark-like layer as they age, and it DOES naturally flake off in strands.

Those bumps or knuckles... small? White?

You are seeing the nubs of advantitous roots forming. It's common for a cannabis plant to try to air-root.
__________________
Since you double-posted, this is getting confusing...

There is nothing wrong with your plant...not DEF, not TOX, not rot; your plants have decided to air-root. They are fine.

Any drop in flower mass- you have to look elsewhere. It's unrelated.

here is a low quality photo of one of the young babes. i will try to get a better image, as this one is very difficult to see, i apologize.

There's nothing wrong with that stem.

Quote:

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Originally Posted by stinkyattic

There's nothing wrong with that stem.

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i am sorry, it is very difficult to see the damage in that photograph. i will try to get a better one. take a look at the other two photos of previously damaged plants, as they show the visible signs of the disease much more graphically.

I did look at them... there's nothing wrong with those either!
Cannabis DOES grow bark... like a tree... eventually it gets too small for the stem, splits, and flakes off!