Leaf curling upward need help

[Yerba]

I have a SFV OG that is 7 weeks old in veg. for the last 3 weeks it has had its upper most leafs curling up and inward the serrated edges are rolling in, they look like green tacos, at first the leafs were showing a light green, so I sprayed a epsom salt mix on them and the color came back nice dark green and still leaf curling up.
They are under CFL bulbs about 3 inches away from the bulb really not much heat at all, I thought it could have been heat stress the way they curled up like a taco.
PH is at 6.3 growing in peat/perlite mix and med feeding with Floranova Bloom at 4 ml/gallon.
Other observations the stems are purple, the veins in the leafs are nearly clear/whittish looking,
I really need some advice, Im trying to get a camera so I can show everyone what the plant is doing.

 

[Kenny Lingus]

Trace elements deficiency I believe...

Trace elements deficiency I believe...

You should try to give more details... (Peat w/nutrient amendments or any lime added?)

Maybe Fe, Mg, Zinc and/or calcium is the clue, butbasically it's some trace elements because it affect the new shoots and young growth...
-main elements would start at older leaves and progress upwards.


I think the thing you must do is make sure the pH is good in the medium, by measuring and always having some drainage. (Peat turns pretty acidic if fed below neutral pH. (Check run-off after you have watered it good in advance: To start with: Water the pots good so a little runs out below with pure pH-7 water. Then after a few hours you water a little more and make sure about 20-30% is running out the bottom. Catch this run-off and measure pH. From this opint you measure the pH of run-off bi-daily and adjust it according to readings.)

 

[Yerba]

I went with just peat/perlite no amendments, All my other strains are fine same feeding with FN B at one time when the SFV got really light green I did a foliar spray with epsom salt and it got really green. Does anyone know what causes the leafs to curl upward like a taco ? I know heat stress, sometimes lack of mg or cal. but what else causes leaf curling where it looks like the leaf folds in half at the middle the serated egdes are trying to meet each other.

Thanks Kenny I am going to look at the plant and try to give more details, should have a photo later.

 

[Kenny Lingus]

K-def may cause scorched edges too...

Seen mynamesstitch's-thread on sick plants? It's in the infirmary.

 

[HeadyPete]

raise the lights 2 inches and see if it helps.

Upcurled leaves is usually heat stress.

Yes you can stress and burn plants with CFLs.

 

[Yerba]

Thanks for the help I have given it a good flush with plain water @ 6.0 ph, raised the light up a little more to see what happens.
I'll keep you guys posted to let you know what happend, thanks KL and HP

 

[stinkyattic]

Even in temperatures that you would think are fine, is the relative humidity is quite low (as it can be close to a light), you will see that symptom.

 

[Sammet]

Up-curled leaves are a natural adaptation to slow down the rate of transpiration. By curling up the leaf tips, the moist air surrounding the leaf surface (from transpiration) is sheltered from mixing with the dry air in the atmosphere. This slows water loss and stops the plant from having to close it's stomata during the day - this is bad because it leads to photorespiration (the opposite of photosynthesis) which is bad for the plant.

Give your plants more water and/or move your lights away a bit. It's not harmful to the plants in the short term, it's just showing they're feeling the stress - hope that helps

 

[Yerba]

You guys pretty much nailed it, The humidity in the air is very low, moderate air temp at 77*, the cfl was about 3 inches with in the tip, I had raised the bulb another 2 inches a couple of days ago making it 5 inches all together, today the leafs are starting to relax more like normal now. Thanks for everyones help on the explantion of root causes and results. This old dog learned something new.

 

[HeadyPete]

Glad that is working out for you.

Thanks for the great info, Sammet!

 

[BENJI]

i had the exact same problem with mine i read this thread and it solved my problem i love i.c mag!!!!!