Flower week 6.4 - yellowing leaves - maybe heat problems

[nizmo]

The reason i suspect heat stress is because the yellowing is worst in the middle and the outside branches which don't get as much light are still quite green. The light has been close enough to feel quite warm on my hand and the fan i have running in the room blows air from the bottom up towards the plants (i.e. no real breeze over canopy).

My main concern is the little leaves poking out of the buds which are becoming yellow. The fan leaves get cut off anyway so i don't mind them looking like shit, but not the buds.

 

[mordecai]

I'm pretty sure that it's natural for a plant to start showing a nitrogen deficiency midway and later on into flowering-- even healthy. But I'm no expert.

 

[nizmo]

My concern is with the second picture, i have circled the areas where the yellowing/dying is occuring on the bud.

Correct me if im wrong, but buds with yellow dying leaves are not normal. The only leaves that should be dying off are the fans.

 

[Cruzin]

Nizmo,

There is a form to fill out that would greatly help. Its some form of burn in my opinion, either PH or Nute. Get on it fast, they look really good right now.

If it was me i would test the PH and PPM of the runoff and adjust accordingly.

 

[10k]

I sure hope you have aggressive full time air movement full time during the dark cycle, else those colas are going to rot badly. enclosed grows tightly packed can back feed that transpired night time wetness right back into the colas and cause a bud rot. I have seen those dieing bud leaves as the mold sets in.

You'd do well to crack open one or two of those fat colas carefully and inspect inside for a grayish sticky wet muck begining.

Lets hope I'm wrong on this nizmo.

ps... nice string work there.
pss... how many week strain is that ?
If it's a long running sat, and not getting rot, I'd defoliate some of the lower big fans to help keep good air flow under the canopy too.

 

[nizmo]

Ill test ppm and ec next water. Im pretty sure they are ok ive been checking what goes in carefully and the soil is quality.

I have good ventilation in a big exhaust fan (no intake - room not sealed). I have a oscilating fan (decent size) on the floor blowing air up towards the canopy. I really dont think its bud rot. There is plenty of room between colas. I did have the light pretty close, and the leaves on the outskirts of the canopy (further from the light) are ok.

No idea what strain it is but i suspect its an 8 week. The pistils are getting brown.

 

[nizmo]

The other thing to note is that this yellowing is only happening at the very top. All the lower buds are nice and green. Does this strengthen the case for light too close?

7 weeks today. The fan's are all getting yellow, but im not sure whether the yellowing on the buds is getting worse. I'll take pics tonight.

Fuck, im probably going to have to pull early. I'd rather have under ripe buds than buds with yellow and dead spots. Only the top cola's getting the best light have this shit going on.

:/

 

[Cruzin]

Personally they would have to look a lot worse for me to pull plants that early. Im sure your issue can easily be fixed, they dont look that bad.

 

[nizmo]

Im sure it can be... but as usual, the extremely hard part is to figure out what exactly the problem is.

Alot of problems have a range of symptoms, and each of those symptoms can belong to a range of problems. Isolating the exact problem, especially this late into flower, is probably pretty impossible given that i have no time for trial and error. I guess i was just hoping someone would say "Yep - i've had something that looks exactly like that before, this is what i did to fix it".

It's been a few days now, and its hard to tell if its getting worse. The fan leaves are definitely getting progressively yellower but i'm not worried about the fans. I am getting a little concerned because the yellowing goes right into the buds and i dont want yellow buds. But since i raised the light there hasnt been any noticable increase in dying bud leaves (when i say bud leaves, i mean the circled parts in the second picture) - but the yellowing is only really happening at the top of the plant. The lower bud sites are fine and green.

 

[Maj.Cottonmouth]

I agree with Cruzin that they do not look so bad that I would pull them. If you do pull them now without resolving the issue what are going to do if it happens again on your next round? Even if you do not resolve it this time you would eliminate some of the possibilities. There is a fan leaf in the upper left of the last picture that looks kinda funky, can you post a better shot of that? And finally I would also recommend that you fill out the sick plant sticky form and post it here.

 

[10k]

Yea they're close enough to just let em finish without worrying too much about those couple of colas having some yellowing. I agree it could be too close to the light since it's happening only on the few colas closest to your light(s). The big fan leaves yellowing is totally normal at this point too.

Now, you still didn't quite answer about whether or not you're running the exhaust and circulation full time during the darkness or not?

If you're not, I'd still be very interested in carefully cracking open one of the suspect colas and inspecting for the muck

 

[nizmo]

If you do pull them now without resolving the issue what are going to do if it happens again on your next round?

Well i'm pretty sure the lights being too close was the issue, and with one week to go now, there probably isnt much more i can do at this stage because the normal yellowing at the end of flower is happening. There was nute burn at one stage, and i suspect that combined with the excess radiant heat at the canopy was the culprit.

The first picture is a closer picture of that leaf you were talking about. Honestly i dont really have much time for that big form right now, but next time i will use it. I'll just post the pictures and answer your questions.

Now, you still didn't quite answer about whether or not you're running the exhaust and circulation full time during the darkness or not?

Both fans are running 24/7. I closely inspected the buds for mould, but they are fine. No evidence of mould at all. Although i do not have a fan blowing directly onto the canopy (which may have stopped the problem happening) there is always air movement in the room and around the plants 24/7. Next grow ill have a fan blowing air directly at the canopy which should enable the lights to be closer.

 

[nizmo]

Trichome pictures.

Starting to see a little bit of amber in the smaller trics.

 

[nizmo]

More trichomes