Serated edges of leaves turning upwards

[Gaz66]

Leaves turning up at edges the tallest of four

 

[Rocket Soul]

Photos?

Could be light stress... Even UV stress. Get some pics in.

 

[PhishPhood16]

I can see your problem.

 

[Destroyer of chairs]

I can see your problem.

Where?

 

[Gaz66]

Hi top leaves on plant do u see ?

 

[hotrodharley]

Hi top leaves on plant do u see ?

Actually no. But raised edges usually indicate heat stress. What’s the temperature at the area it’s affected? How high is the light? Type of light including actual wattage and percentage of power if it has a dimmer?

A pic showing actual area of concern in normal light would help.

 

[Gaz66]

Hi temps low 20s 250 w led was about 15 inched away moved to 20 now. No dimmer I'll get you over a pic shortly thanks seeming to affect tallest plant

 

[Gaz66]

Hi first 2 pics are the affected plant 3 rd pic are the other unaffected plants in tent slightly shorter plants thanks in advance

 

[Gaz66]

If it is heat stress will the plant recover fully ? Looks like it is I thought maybe too much light or insufficient circulation

 

[DukeFluke]

That's just the top of your plant being in a different environment to the rest of it, ie dryer and hotter. That's what's causing the curling and why it's not happening to the short ass. Best way to combat that is super crop the tall ones, keep the canopy nice and even and keep the light intensity rather than moving it from the majority of the actual foliage in there

And yes they can fully recover from that almost immediately.

 

[Gaz66]

Thanks for advice dunno about super cropping novice 1st time grower.. can you actually do super cropping they are autos just started flowering ?

 

[DukeFluke]

Yea you can do it it's just squeezing the stem where you want to bend so it becomes supple and bends easily. Bend it very slowly and squeeze above and below where you want to bend it to make it more supple. Squeeze til you crush it and it should fold easily. It'll fully recover in a few days with a nice knuckle and a more even canopy.

 

[Craigson]

MAC1 clone only seems to do that no matter what environment. At least the pics on CAPs forum show that.

Coukd be genetics or coukd be heat stress/too low humidity

 

[Gaz66]

Can you do at on main stem as that's where problem is ?

 

[PSUAGRO.]

Hi first 2 pics are the affected plant 3 rd pic are the other unaffected plants in tent slightly shorter plants thanks in advance

My guess from these limited pics would be genetics......

 

[Gaz66]

So does that make it ok or is the plant going to fail ?

 

[Gaz66]

From the early stages the tips were always browny beige at the tips

 

[PSUAGRO.]

Ladies should be fine grower...... Update if "issue" spreads/ intensifies

 

[Gaz66]

Thanks

 

[Puff_Dragon]

Hope this helps:
I run Samsung QBs (set to the maximum setting of 240 Watts). 18 inches is the sweet spot for me.
Any lower, most of my strains will show curled leaf edges (like yours) at the top of the plant. This level of 'stress' can stunt growth (so I have been told)