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[pop22]

Can anyone help me determine why the edges of some leaves are starting to canoe/curl? I've tried to maintain temps between 75-82, but they have swung from 70-86. I bought a humidifier specifically for this tent, so humidity has been kept between 40-55%. I was thinking that it might have been something to do with the super soil, but there's no signs of burning or discomfort other than that. My other thought was that it may have been from the irrigation system. I used it for the first time last week at full pressure and thought I may have disturbed the root system with water pressure. If you have any ideas let me know. Here are some pictures of it:

When the heat gets too high, the edges of the leaves will begin to curl up and the leaves will begin to "cup." could be your light is too close?

 

[gbd]

When the heat gets too high, the edges of the leaves will begin to curl up and the leaves will begin to "cup." could be your light is too close?

Heat stress was my first thought too, but the light is 40" away (the furthest I've ever had it) and temps haven't been anything too crazy. Tang posted a link to a video that suggested plants grown under LED be kept at 85 degrees and 35% humidity. That seemed a little warm to me, but I'm no expert. The 2015 releases are under the same conditions and don't seem to have been affected. I've started to monitor the temp even more closely to determine if the curling stops or continues under approximately 82 degrees. Thanks for stopping in with ideas, Pop!

 

[pop22]

Then it may be over watering. The plant in the pic is a little rough, but it looks like the curl your leaves have:

http://www.growweedeasy.com/sites/growweedeasy.com/files/overwatered-marijuana-too-long.jpg

 

[gbd]

Then it may be over watering. The plant in the pic is a little rough, but it looks like the curl your leaves have:

http://www.growweedeasy.com/sites/growweedeasy.com/files/overwatered-marijuana-too-long.jpg

Hmm, maybe. I became pretty familiar with the look of overwatering while learning DWC. I'm thinking you were probably right with your first suggestion about heat stress. It seems to have only affected some plants, so it might be that a certain pheno is more sensitive to it than others, or it could have just been to damn hot! Hopefully it doesn't keep up. Thanks, pop!

 

[Margahooja]

I had that in my 24 carat. It started early on and through the whole grow. Everyone told me heat stress but It was right along side the Chemdogging that had none. It drove me crazy but in the end it did'nt affect the plant that I could tell. By the way, all the pictures are showing when I view on my Ipad, must have been something with my computer.
In my thread I could see it in photos on day 14 and then on.https://www.autoflower.org/f149/24-carat-chemdogging-margahooja-37874.html

 

[Grim Reefer]

Looking great Gbd, i cant wait to see how these girls fill out. Yeah i have to agree with pop, looks like heat stress. As you said could be a pheno but i have always found that if you measure the temps at the plant canopy level and not the ambient room temperature you will find the plants usually dont like as hot as 82F. For me i find the plant canopy level should be at around 78-80F while the ambient room temperature could be higer say up to 85F. Try get a small hygrometer to place right were your plants are as i find that the readings change dramtically on the sides/ top and bottom of the tent.

 

[A4]

Can anyone help me determine why the edges of some leaves are starting to canoe/curl? I've tried to maintain temps between 75-82, but they have swung from 70-86. I bought a humidifier specifically for this tent, so humidity has been kept between 40-55%. I was thinking that it might have been something to do with the super soil, but there's no signs of burning or discomfort other than that. My other thought was that it may have been from the irrigation system. I used it for the first time last week at full pressure and thought I may have disturbed the root system with water pressure. If you have any ideas let me know. Here are some pictures of it:

Hey gbd, I am looking through your pictures and am thinking transpiration problems. Are you getting good air flow around your leaves? My guess is, as low as the canopy is to the soil coupled with the soil staying pretty moist, the leaves aren't breathing too well. If they aren't transpiring optimal you will get what looks like heat stress. On the same subject, you will get almost the exact same response in an environment with low RH and high wind flow except in those cases you will likely be seeing some yellowing of the smaller, young fan leaves being formed at the top of the plant because the plant is transpiring too quickly. I don't see any burn on the tips so my guess would be lack of air flow.

 

[gbd]

I had that in my 24 carat. It started early on and through the whole grow. Everyone told me heat stress but It was right along side the Chemdogging that had none. It drove me crazy but in the end it did'nt affect the plant that I could tell. By the way, all the pictures are showing when I view on my Ipad, must have been something with my computer.
In my thread I could see it in photos on day 14 and then on.https://www.autoflower.org/f149/24-carat-chemdogging-margahooja-37874.html

Thanks for the heads up, Marga!

Looking great Gbd, i cant wait to see how these girls fill out. Yeah i have to agree with pop, looks like heat stress. As you said could be a pheno but i have always found that if you measure the temps at the plant canopy level and not the ambient room temperature you will find the plants usually dont like as hot as 82F. For me i find the plant canopy level should be at around 78-80F while the ambient room temperature could be higer say up to 85F. Try get a small hygrometer to place right were your plants are as i find that the readings change dramtically on the sides/ top and bottom of the tent.

Heya, Grim! All the temp/humidity readings have been at canopy level. The highest they've gotten up to was 86 degrees and that was only temporarily. The ambient temperature outside the tent is about 65 degrees. I think A4 hit the nail on the head in his post.

Hey gbd, I am looking through your pictures and am thinking transpiration problems. Are you getting good air flow around your leaves? My guess is, as low as the canopy is to the soil coupled with the soil staying pretty moist, the leaves aren't breathing too well. If they aren't transpiring optimal you will get what looks like heat stress. On the same subject, you will get almost the exact same response in an environment with low RH and high wind flow except in those cases you will likely be seeing some yellowing of the smaller, young fan leaves being formed at the top of the plant because the plant is transpiring too quickly. I don't see any burn on the tips so my guess would be lack of air flow.

A4, I do believe you've hit the nail on the head. There is barely any airflow, in fact I just added one small tower fan last week and bought a clip on oscillating fan over the weekend. I will get it put up today. Thank you for the information. I'll get some air flowing and see if that doesn't help things out a bit.

Cheers!

 

[gbd]

So I've got some fans in the tent circulating the air nicely, but I noticed these sickly leaves today. Could this also be from transpiration issues or does it look like something else? Any input is appreciated.

Other than that everything seems to be going smoothly.

 

[gbd]

Day 20. I switched everything over to 20/4 yesterday. I'm hoping the leaf issue is just from spraying them with water while the lights were on and not a sign of thrips or any other infestation. That would be horrible. Anyway, here are the lasses: