Mysterious, sudden orange-yellow spots on leaves

Hello to anyone who can help,

I am new to this forum and I truly hope someone can come accross this with the solution.

My friend has a small setup in which there is three plants. One's in late flowering and was tagged with the name "Fire". (I'll refer to the plants by their codename as I go on) Another, which is in early flowering, tagged "Water". The last one has just entered my buddy's bloom room and is tagged "Flame".

"Fire" has had an interesting past. It almost died of overheating until I noticed my friend's airflow setup was mediocre, allowing temps of over 100 deg. F. Once it survived that ordeal, it took roughly two weeks to get back afoot, and showed a few signs of nute damages throughout. It finally regained full-pace not too long ago and has been doing great.

"Water" is relatively new to the room. 2 weeks in flowering and nicely going. It had a slight transplant shock in its life, but no other adversities.

"Flame" has just joined in a few days ago and I visited to check up on things.

Now, the mysterious, new problem. Last week, I installed a 4" can fan on the setup which brought the temps down from ~90F to ~80F. I also helped my buddy by handing him some BushMaster to stop the plants from trying to reach the moon. (Hey, with the night/day temp diffs he had before, I wasn't surprised)

Two days after the BushMaster treatment, I found "Fire" covered in orangish-yellowish spots. Some of the leaf tips are burnt with an orange, rust-like color. "Water" showed the same symptoms but on a much smaller scale. The problem seems to want to affect the fan leaves first, starting with the middle of the plant on both plants. "Flame" is unaffected by this as is has just entered the room after the problem appeared.

So, thinking this was a nute problem, I flushed. Not intensively, but enough for water to run down under the pot. I put roughly 1 liter in a 1 gallon soil pot. This, for each plant.

Did the problem subside? Well, not really. It's simply slowed down. "Fire" seems to be taking it well,though. Its growth rate has not slowed down: In fact it's sped up since the BushMaster treatment - without stretching. "Water" seems to be coping as well, but the worry is the problem is slowly but steadily propagating. The higher fan leaves are beginning to show symptoms and I fear it won't be long until the next set above follows suit.

Conclusion? The problem hasn't gone away. What is it? I've heard nute burn, fungus, virus, etc, etc...
But no one I've described this to have seen pictures, until NOW

I finally zoomed by with my camcorder and got a few vidcaps of the problem.

PS: These images were color-graded; the red spectrum has been reduced and the brightness then increased.
This has removed the orange tone caused by the HPS lights, thus giving out more realistic colors to the viewer.
Another note... The spots are NOT white. It may seem like that on a pic or two, but I'm convinced bugs are not at work: I cannot see distinct signs of parasites on any plant nor can I find even a trace of web, thus eliminating spider mites, which would have had a feast on the crop by now. A fungus seems more plausible, but still farfetched IMO.

Oh! Another note... First 2 pics: "Fire" - putting the problem aside she's got this "cool" new look that matches her name. Next 4, in order: "Water"'s mid-fan-leaf, then "Water"'s mid-top-fan-leaf, Then an overview of "Water" and finally a closer look at the bottom-fan-leaf.

Anything? Write. Help. Please. Thank you. In advance.

To anyone who may have read/seen this post already...

Looks like in roughly one day, no one with knowledge of plant rust has come accross my post.

That's right folks according to my "local specialist", these here are symptoms of Rust Fungus.

The "local specialist" handed me a sulfur based spray, which is said to rid of the problem completly. I will try this tonight when I visit my friend.

Sorry to all who thought I was a newbie who should read the FAQ, but this was posted after much research trying to find the answer to my question, all in vain.

Also, to those who scratched their heads at this: Might want to copy my pictures and use them to document what cannabis looks like when attacked by rust.

Stay tuned for further info, such as recovery progress and other details that may come up.

Im a newb too, but it looks like you may have a infestation problem. Looks like spider mites. Im not sure consult with a more experienced grower.

bdoessentials said:

To anyone who may have read/seen this post already...

Looks like in roughly one day, no one with knowledge of plant rust has come accross my post.

That's right folks according to my "local specialist", these here are symptoms of Rust Fungus.

The "local specialist" handed me a sulfur based spray, which is said to rid of the problem completly. I will try this tonight when I visit my friend.

Sorry to all who thought I was a newbie who should read the FAQ, but this was posted after much research trying to find the answer to my question, all in vain.

Also, to those who scratched their heads at this: Might want to copy my pictures and use them to document what cannabis looks like when attacked by rust.

Stay tuned for further info, such as recovery progress and other details that may come up.

Click to expand...

looks to be powdery mildew, if its now powder, then look for bugs like spidermites, or thrips

looks like mites

Looks like one of two things to me. Either mites or over watering.

There are NO spider mites at work. No webs, no spots. I would have these by now.
There is no powdery mildew, although I suspected the same.
It is also not overwatering - these plants have only been soaked due to flushing, and this was only twice in their lifespan.

It's ok, guys. My "local specialist" (employee in a Hydro shop) has diagnosed by looking at a leaf, along with 3 coworkers.

This is rust fungus. Some may want to visually document the problem by taking my pictures as this is a rare occurrence I could not find any info about. (Look up Plant Rust in google images - you won't get cannabis leaves, but you'll see that the symptoms are the same, regardless the plant)

I'll give more word on the recovery, which starts with using a mild sulfur foliar spray.

I stress documenting this and using my pictures given the problem is very misleading and may force the grower to take useless measures (insecticide, no watering, nutes, etc) without addressing the ongoing problem.

Of course, if it is a misdiagnosed problem (wow, I'd be surprised), I will promptly update this post (with a tad of shame, of course)

Honestly bud i had this same problem only it was during the veg stage. Over night both plants had rust color spots that seems to travel in between the viens of the plant. I freaked out cuz it seemed to be spreading over the fan leaves at a very rapid pace.
This also happened right after i had introduced the first full stregth nute schedule around week 4. So after freaking out and flushing and tlc it still kept dying.
But it was only to the fan leaves....it was still growing fine and new very lush growth was coming out from the tops and nodes.
There really was no problem to be had....just another stage in the plants life. I have had some plants do this exact same thing, and some have not. May be different strains or just a normal reaction to the nutes...im not sure.
But if you have healthy undergrowth that is not effected by these spots and they just stay to the fan leaves then i think you are going to be alright. If it was a true virus or bacteria or bug, it would not just stay on the fan leaves, your whole plant would be effected. Nute burn will usually travel from the bottom up and over/under water will be seen thru the whole plant right away.

EDIT: added pics. the first one is at the end of the cycle....week 6-7 of flower and the second is the same plant at 4 weeks of veg....as you can see the rust spots never went away totally. the fan leaf would die and be replaced is all. Too bad it was my ONLY mango kush seed i had and the fukker ended up being a male....but i did save the pollen from him!

That doess seem similar...

However the prob we have looks more like a bad eczema attack on a plant Really, I initially took the attitude you have toward your problem. Only the fan leaves, must be somewhat normal, not desirable but not critical.

But then it got worse on the fan leaves, started making a few dance the twist. Then some of the smaller leaves got slightly affected. This is where I figured screw this, there's something wrong here.

My buddy's lucky the guy at the hydro shop knew the problem.

I applied Safer's Defender foliar spray as intructed and will monitor the progress. I think I'm out of the woods. ( Or actually back IN the woods, depends the way you look at it )

What is this I have it too