What causes the Claw?

[Jimboswood]

I read a couple of years ago a really good (convincing) reason that someone gave for the claw. One that actually seemed to perfectly fit with my conditions at the time ...

Trouble is my memory's not so good and I can't find it by searching ...

I don't think that too much N is the only reason. Certainly not in this case anyway ...

I seem to remember that it was explained as a RH problem, when the plant shuts down stomata as water starts to leave the plant into the atmosphere.

Hoping someone can help me remember better ...!
Cheers !

 

[HigherTheHigh]

Re: What causes the Claw ...

clawing down is usually nitrogen and clawing up is usually heat.

 

[Why Doe]

Heat, lights too close, low humidity.

 

[Scientific]

The textbook claw with leaf tips pointing down sharply is supposed to be a classic sign of too much nitrogen.

 

[Brewer]

one of my first grows had the claw, turned out to be fungus gnats

 

[Scientific]

one of my first grows had the claw, turned out to be fungus gnats

Interesting. You don't happen to have a snapshot, do you?

 

[Mayne]

could also be cold.

is it all day, or noticeable after night cycle? Your plant should be at 75degrees, constant, to 80degrees.

is the fan blowing cold air on them?

 

[Mayne]

if they curl and burn the tips, then it could be not ENOUGH nitrogen.

 

[Scientific]

could also be cold.

is it all day, or noticeable after night cycle? Your plant should be at 75degrees, constant, to 80degrees.

is the fan blowing cold air on them?

I don't think the various scenarios you mention are causes of the "the claw," the classic hooking down symptom. Lots of things affect the leaves, but a case of clawing is pretty distinct.

 

[Jimboswood]

Thanks for all the replies ...
The problem's now restricted to the older leaves ... and isn't spreading at all.

I'm trying fairly heavy defoliation this grow, so they'll soon all be gone anyhow ...!

Despite running my nutes at 400-600 ppm, temperatures never above 80 and 5 degrees lower at night (before I started running CO2 anyway) I still got clawing on 2 out of 9 plants. So I'm "reasonably" sure it wasn't N or heat conditions. I did however have a few days of some very high AND low humidity levels !!!! Took me a while getting to grips with new growroom air conditioning system

Anyhow - back on track now - thanks to everyone who replied

 

[Scientific]

I still got clawing on 2 out of 9 plants.

Some photos would have helped. "We can speculate endlessly in the absence of data."

 

[HigherTheHigh]

With every claw iv had iv found a difference between to much nitrogen or to do with a fan.

With nitrogen i find theres no trichome production at all or very little and bland.

With there being a problem with the fan is usually still clawed but trichome production is the same as any other flowering plant.

iv found that with every one of my plants like that.