Disease with pics. Lumps growing on stems of plant slowly kills plant

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Aug 21, 2005
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I am from Australia. I have a mate who grows indoors. He has a disease that is affecting his flowering plants.

He has 2 seperate small grow rooms, 1 for grow and 1 for flower. There is a disease (He thinks) attacking the plants in the flower room. Its only affecting a few of them, not many as bad as the one pictured. It eventually kills the whole plant leaving him with dead buds. It acts slowly, and He has acted even slower to cure it. He has had the disease in there for months.

As you can see the plant has small lumps growing all over the stem, and the plant is on its way to death. Only seems to be affecting flowing plants for now. Hes not sure if thats just because it hasn't jumped rooms.

If anyone could suggest what this disease is he would be most appreciative. A reliable cure would also be nice. Don't mind chemicals so he has no problems going to the plant shop and buying an off the shelf cure.






Hey OZ,
I am curious about several things I see in this picture. The first thing I noticed is the width of the stems...pretty large for an indoor system. What sort of lights/soil are being used? If high intensity lights are being used, how far are they from the plants?

The second thing I notice is the splotchy fuzzy/white/grey spots that seem to cover the stem in a repetitive manner. To me, it looks like mold/fungi. What is the ventilation/aeration/humidity situation of your friends garden?

Marijuana does NOT like an overly humid/hot environment.

Soil PH is also very important.

Let us know how it goes!

All plants have been clones for years now. Clones are generally taken before the plant is moved from grow to flower room.

The lamp is a 600 watt Agro HID lamp. Some plants get to as close as 30cm (12 inch) below the lamp. But the plant in the picture has been over 1 meter from the lamp most of its life.

Medium is perlite and vermiculite mix. about 60% perlite.

The plants are watered with PH nuetral solution of flowering nutrient from the hydro store. They sit in a comunal tray of water which gets filled. Then the plants consume this solution and are left a few days without solution to dry out. So they sit in the solution for say 4 days and then dry out for another 4 before the cycle is repeated. This is probably not good for them, but it has been done this way for years there hasnt been a case of root rot yet.

Ventillation is 1 250 mm exhaust fan and an internal fan to move air around. The white patches weren't as obvious on the plant, but they are in the photo (maybe flash doing stuff). They were sprayed with Fungus Fighter (Yates brand, Copper Fungicide, 400g/Kg Copper as cupric hydroxide). This seemed to have no effect positive or negative. It is a powder that is mixed with water and is sprayed on the plant. When it dries it leaves a purlple powder on everything and this may be what you are seeing.

There is mould in the grow room. In the trays where the water sits, and on the top of the perlite in the pots. But the room has always had this mould (for about 5 years now) and never had root or bud rot.

But in this case I dont think that mould or PH/nutriant is the problem (could be wrong). I am pretty sure what is growing on the stem is an organism. You can pick the little lumps off the stem and the stem looks almost unaffected underneath. The little lumps have a hard outer shell and are gooey inside.

Many other plants have been in this room and gone through flower cycle unaffected. Only a few (say about 6 over 12 month period) have had the lumps this bad, like covering the whole stem, and killing the plant.

Thank you for your time friends.

WoW 0zguy. Nasty shit, whatever it is. I'm at a total loss as to diagnosis.
Even in my research, I've not seen the likes.
IMHO, the setup doesn't sound.."ideal" but sufficeint, and if it has worked for years without the problem. I'm guessing that isn't the culprit.
I'll do some lookin'/askin.
Holy shit.
I have never had anything happen to me like that so I'm at a loss too.
I'm not sure what it is (could be a virus) but I know how to cure it.
Gut the grow room. Take every thing and I mean every last freakin thing out of there, even to stripping the paint, then spray walls/floor/ceiling with a water/bleach solution.
Re-apply paint/mylar, put a poly tarp on the floor.
Now, rig up ventilation. Use a dehumidifier to control high humidity.
Everthing that you took out of the room wash down with water w/bleach before putting back in.
Everyone wash their hands before going into the grow area.

My plants once has some sort of disease. I couldn't figure it out. It was slowly killing my plants. I cleaned everything out twice, it would come back months later.
Then I found out what it was.
I roll my own cigarette's. Tobacco is sometimes infected with tobacco ring-spot virus. It survives the curing/manufacturing process, and when you roll cigs the virus gets on your hands.
In only affects tobacco--and marijuana.
So I was infecting my plants when I touched them.
The solution was simply washing my hands before going into the grow room.
Thanks for the advice guys.

I will have to wait a few weeks till everything finishes flower cycle, but then i will empty out the flower room and give it a good clean top to bottom.

I will let you know how it goes. Thanks again.

good answer ganja . an old man told me that along time ago about my tomatoe plants . dont touch your tomato plants after smoking . i listen to everything you tell me . except miracle grow . well just have to scrap about that 1 lol.
I have now been told he is quite sure its a bad case of scale.

On the rest of the plants (ones not pictured) the affects have been substantially less. The plants are still mostly green with more dead folage than usual. They still produce buds, but quantity and maybe quality has been diminished. Small Hard skinned objects form on the stem (and rarely leaves). If picked at they have a gooee inside substance that the hard shell protects. Some plants have only a few, say 5 spread over all the branches and main stem. Some plants have substantially more. Very Very few like the one pictured. Also some plants have small patches of scale generally on the low woodier part of the stem.

As per advice from the local hydro shop (shop guy said its fairly common) my friend is treating it with Neem Oil and Liqued Soap (and of course water) spayed on the plant once a fortnight. He has just started, I will let you know how it goes.

Columbian Connection said:
I like Miracle Grow too.

I no longer use Miracle Grow for the following reasons:

99% of experienced growers Ive talked too (including hydroponic store owners) have said only use Miracle Grow if you cant find anything else

Its not specifically for growing marijuana, its a general plant food, why buy general plant food when you can buy plant food specifically formulated for growing marijuana?

All purpose Miracle grow is a 15-30-15 (from memory) which I would consider an average plant food for growing marijuana. During veg you want a high 1st number so I would say Miracle is pretty good for vegging but when it comes to flowering you want a high 2nd number and I use Jon's Yield Booster which is a 0-50-30 (almost twice as potent as Miracle grow for flowering) and have noticed much better flowering results than my plants last year (last year I used Miracle Grow).

Well in conclusion I would say Miracle Grow will do the trick, but I have found that there are much, much better plant foods available that are specifically formulated for growing marijuana. After seeing the results of using plant food formulated for mj and results using Miracle Grow, I would never go back to Miracle Grow.
OZguy said:
I have now been told he is quite sure its a bad case of scale.

Bad??!!! What a nightmare. That's what would have happened to my plants if I hadn't inspected them minutely for days, scraping off leaves and stems probably about 1.500 scales from 3 plants. Now a month later they haven't got hardly a scale on them, but are still weakened. I think the serious damage will continue for about 2 weeks after you've removed all the scales. They literally suck the juice straight out of the plant. They are often milked (and protected) by ants who are just crazy about their honeydew excretion. Oil/soap doesn't work very well, only really kills the crawlers (the insects before they find a home and build the shell). You have to do it manually. Check every bit of the plant, top and bottom of leaves, and they especially like the apex between stem and shoot. Little penknife does the trick. I think mine came from nearby citrus trees, at least I have found the same scale on an orange tree.

Good luck!
sounds whorrible, what bug does this to the plants? and how can you prevent this?
skunk said:
good answer ganja . an old man told me that along time ago about my tomatoe plants . dont touch your tomato plants after smoking . i listen to everything you tell me . except miracle grow . well just have to scrap about that 1 lol.

What the hell's wrong with miracle grow, i've been using it since i was 19 and it's just great... i'm 43 now.
makes me want to bathe, vomit and itch all at the same time...
I don't know if it's relevant now -- but I have the same problem. It's called "scales or mealy bugs". They hide under the waxy little bumps and lay eggs. Absolutely DISGUSTING! I used a spray (organic pyrethum) and then used isop alcohol on a cotton pad and literally wiped them all off. This will kill them on contact. I use a book called "Marijuana Garden Saver". It has pics of all different diseases, pests, environmental stresses, and nute disorders.
sounds like an awesome book thanks...that is the most diseased plant I have ever seen...and I am not the best gardener..lol
2Dog said:
makes me want to bathe, vomit and itch all at the same time...
........:confused: the "Miracle grow?"...... :hubba: :rofl:

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