Leaves curling up: Is it Mg defeciency? Input needed

M00gle

New Member
I was wondering if anyone could help me figure out this problem my friend is having. I believe it's a magnesium defeciency so i told him to correct with a 1/4 tsp epson salt/gal. but the plants leaves are still curling upward like they are praying. Plant growth looks good but I'm worried the problem will get worse if he doesn't act quickly. Only 1 of the 4 plants has this problem which is weird because they are all growing in Fox Farm Ocean forest and have been getting the same nutes. Any help is appreciated.

background:
-plant with problem is a sativa strain
-I normally feed with RO 6.0 ph water but moved up to 6.5 for last feeding
-plants are in FF ocean forest
-plants are 4 weeks old and in 1 gal pots. (will repot soon)
-Temps = 68-78
-RH= 44-50%
-Light= 400watt digital MH (1.5ft away)

Also one plant (AK-48) has a orange spot on it. I don't think it is a big problem but hope it doesn't spread. Lemme know what you guys think. Thanks

Leaf curling but no discoloration
grow3_1.jpg


Same plant but bigger view
grow3_2.jpg


Some weird orange spot
grow3_3.jpg
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Yeah most of the growth looks good as you say.... but the new leaves are showing more and more curling. See what you think of these pictures.

grow3_5.jpg


as you can see in this pic the new leaves are curling upwards alot.
grow3_4.jpg


Hey Boss.... the temps have gotten above 80 but the majority of the time they are below 80. I've read that the leaves sometimes curl upwards because they are trying to dissipate moisture. I think because it is the new growth that is experiencing the most curling that the light may be a bit to close. I'm going to try moving the light up a bit.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

It's a bit easier to see with a bigger image. As I said earlier, this form of upward curling is a sign of very rapid growth on a healthy plant. It is obvious the plant is relishing the nutrients you are currently giving - this is a sign that less is more. If you kept adding ferts or dickered around, the leaf rims would show yellowing, which is the indicator of fert burn.
You are lucky to have a plant so healthy. Don't fret ok.
grow3_5.jpg

grow3_4.jpg
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Leaves will do this to lose moisture too. Some strains like it drier than others. They will curl in the opposite direction when they are trying to retain water, making an upside down cup to trap moisture. Unfortunately, I could be completely wrong, I have never read it anywhere, I just noticed it while I was growing. I guess it could be caused by something else, I have no clue :)
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

There is a problem there. A slight cupping is normal but that's extreme. Those leaves are going through some extreme transpiration. Either the lights too close, the fans too strong/close or the box is too hot. Something is making them try and sweat and sweat hard (transpire)
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Well I had my friend raise the lamps up a bit and it seems to help with the curling. Hey Racefan... If a fan is pointing directly at a plant could this cause the upward curling we're seeing?
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Well I had my friend raise the lamps up a bit and it seems to help with the curling. Hey Racefan... If a fan is pointing directly at a plant could this cause the upward curling we're seeing?
Yes. Too much wind for prolonged periods can start to dry out the leaves. The first stage is for the plant to reduce surface area and that requires they curl. If heat is involved they curl up because the stomatas are on the bottom and that's where plants sweat (transpire) the most from. If they were to curl down they would block the stomatas and hinder their ability to transpire and cause them to dry out faster. Eventually the leaf will die unless steps are taken. It's also a good bet that if one leaf is affected more are too. Your pictures show this. Raise your light and reduce the direct air contact and see if it helps.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

I knew I had seen this problem before so I went back and looked at some notes I had taken years ago and found that the taco effect yojur experiencing is due to either a MG or a iron def. Nor sure which one as my notes weren't the clearest back then.lol Get some epsom salts and apply at a 1 teaspoon per gallon dose. Look for a product that is high in Iron. I know one that I used years ago called "stay green" and I know there are others as well. Together they shouldn't cost more than $10.00.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Ah good info racefan. The plants are doing ok after telling him to take off the heat stress and move fan. Still some curling but not as bad. Thanks.. you rock man. You always have some good ass info.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

They are doing better because you pulled the stress inducers back and they don't have to work as hard to survive but the tacoing effect will not go away completely until you treat the symptom. And thank you for the props. I do take rep points as payments you know?;););)
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

hehe racefan I already tried a while ago. But it says I must spread around the rep more.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Same issue but growing outside. I cant pull the lights back so Im thinking too much watering is the culprit...
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Looks like heat stress. The brown spot looks like a P or K def or a water burn from ur lights.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Looks like heat stress. The brown spot looks like a P or K def or a water burn from ur lights.

Sorry I have no pics posted.. But they are starting to curl that way. I believe it might be from overwatering. As far as heat stress is concerned, are not these plants supposed to thrive in the full sun?
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

That looks like a heat issue. Underwatering combined with heat will make leaves edges bend up as a cooling mechanism. Maybe by chance your spraying your plants too often in the heat of day and making the leaves take too much amplified light/heat. Pull the lights back and see if it goes back away....takes la night in cool temps for the plant to snap back also.Another option is regulate temp a bit better with a fan blowing between light and plants area to clear that heat before it gets to the plants....:goodluck:

If it was MG it would be due to the PH being out of whack....that does not look like a MG deficiency at all.
 
Re: Leaves curling up... but is it Mg defeciency? Input needed.

Hope this helps! :high-five:
 
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