Could it be too much air movement?

[dankhoe417]

These babies sprouted 7/18 and are doing good growth-wise. However, I am seeing the leaf curl on several. Watering 4x daily, drip method. Roots are healthy and vigorous. I constantly battle heat in this 100+ degree weather, but supplement with an a/c unit. Temps are 82/85, but I also added a rather large pedestal fan I already had, but have it blowing against wall for air movement. The plants wiggle constantly, but I wanted to strengthen stems.

1000w MH w/ glass about 3ft from them. New growth looks great and am running ph approx 5.5 - 6, 25% solution of GH grow and micro.

Could it be too much air movement drying out the leaves, or ??????.

Could use some guidance.

 

[TheOrganic]

I wouldn't say that's from the fan..Looks like to much heat and light.They look a little crispy. The curling up is from it trying to hold moisture in its leaves.

 

[borbor]

based on that, move the plant lower down or the light farther up?

 

[Muffy]

I think it's heat stress. If you're just blowing hot air across the leaves it won't help much. You can run the fan intermittently and still strengthen the stems without dry out your plant.

Are you running the light 24/7? Whatever the schedule, try giving it some extra darkness to let it recover.

 

[unity]

Looks like heat stress. You need to get the humidity up, and/or the res temp down, and/or the air temps down, and/or increase watering intervals and/or reduce the fan speed while you are under extremely dry conditions. What climate zone are you in? Not all of the things may be practical for you at this point, but you mention that you supplement with a/c, so lets start by increasing the efficiency of your a/c. Tell me more about how you implement a/c?
Kind

 

[Muffy]

Why don't we just all agree right now that the 1k is overkill? That plant isn't using all the light but the grow is being affected by every last bit of heat. Get a smaller light and you won't have to rely on the a/c for a while. When the canopy shades the bucket would be time to pop in the 1k.

 

[jondamon]

The leaf roll you are experiencing IS caused by a humidity problem.

That humidity problem could be from a number of different factors such as

Oscilating fan position
Oscilating fan Speed
Room Humidity
Canopy Temperature


Basically the Humidity on the leaf surface is VERY low causing the leaf roll.


You havent once mentioned what your humidity is?

Could you do a room test for Humidity and also a test for what the humidity is at the plant level.

This will help to isolate which is at fault, I cant see that the temps of 82/85F alone will cause this problem it could be a culmination of all the factors causing the problem.



J

 

[dragnit]

Increase humidity to at least 40 % and try to reduce heat down to a max of 86 5 F for better start. Looks like you have deficiencies .PH maybe lock out .

 

[*BUDS]

These babies sprouted 7/18 and are doing good growth-wise. However, I am seeing the leaf curl on several. Watering 4x daily, drip method. Roots are healthy and vigorous. I constantly battle heat in this 100+ degree weather, but supplement with an a/c unit. Temps are 82/85, but I also added a rather large pedestal fan I already had, but have it blowing against wall for air movement. The plants wiggle constantly, but I wanted to strengthen stems.

1000w MH w/ glass about 3ft from them.

New growth looks great

and am running ph approx 5.5 - 6, 25% solution of GH grow and micro.

Could it be too much air movement drying out the leaves, or ??????.

Could use some guidance.View attachment 1722945View attachment 1722946

Yes but for how long? What is the ppm i think its too low and your getting def. The canoeing is due to the heat, make it 4 ft for the light.

 

[Muffy]

The leaf roll you are experiencing IS caused by a humidity problem

I've had leaves roll up like that at 90% RH. It was really hot too.

 

[jondamon]

I've had leaves roll up like that at 90% RH. It was really hot too.

Yes and it can still happen because of the Relative Humidity on the LEAF surface, it forces the stomata on the leaves to close to retain moisture this is why the roll happens, it can be because of high temps which are causing the RH on the leaf surface to be ALOT less than the RH of the room and thus the roll happens.




J

 

[dankhoe417]

Thanks all. Humidity normally sits around 55%, but with this damn heat, I struggle maintaining 45%. I have a rather large humidifier right next to plants that uses about 2 gallons of water daily. I changed a couple of things. Only have the 1k MH at this point, so moved it up all the way(approx 4 ft), moved the ballast out of the room, turned the fan around and am running exhaust 24/7 now. Running 18/6 lights. Window a/c runs 1.5 hrs on/ 30min off during light cycle. 30/30 during dark phase. Hopefully this will perk them up a bit. Misted leaves with balanced, distilled water a couple of times today. Changed nutes today too and perked the N up a bit. In the midwest, so temps outside are daily 104+ lately. Hit a few high temps a week back, 93-95, while out of town. Kicked up the a/c as a result. Hopefully they will come around. They are BigB, so they are pretty aggressive.
Thanks everyone for all of the feedback. Will post comparison pic after a couple of days.

 

[Muffy]

Yes and it can still happen because of the Relative Humidity on the LEAF surface, it forces the stomata on the leaves to close to retain moisture this is why the roll happens, it can be because of high temps which are causing the RH on the leaf surface to be ALOT less than the RH of the room and thus the roll happens.

What makes me doubt is that by rolling the edges up the plant is exposing surface area which makes me think the plant is trying to evaporate or transpire even more water to cool itself down. Rolling leaves down would shelter stomata from wind movement acrosse the width of the leave, maybe doubling the effect of closing the stomata. You know humans don't breathe through the skin but the skin breathes. Must be something similar with plants.

 

[abberation]

Thanks all. Humidity normally sits around 55%, but with this damn heat, I struggle maintaining 45%. I have a rather large humidifier right next to plants that uses about 2 gallons of water daily. I changed a couple of things. Only have the 1k MH at this point, so moved it up all the way(approx 4 ft), moved the ballast out of the room, turned the fan around and am running exhaust 24/7 now. Running 18/6 lights. Window a/c runs 1.5 hrs on/ 30min off during light cycle. 30/30 during dark phase. Hopefully this will perk them up a bit. Misted leaves with balanced, distilled water a couple of times today. Changed nutes today too and perked the N up a bit. In the midwest, so temps outside are daily 104+ lately. Hit a few high temps a week back, 93-95, while out of town. Kicked up the a/c as a result. Hopefully they will come around. They are BigB, so they are pretty aggressive.
Thanks everyone for all of the feedback. Will post comparison pic after a couple of days.

Seems like you on the right track to fix you problem. If you still continue battling high temps, try adding CO2. Plants handle higher temps better with a higher level of CO2. The only problem you might have is that you exhaust 24/7, which will suck all the additional CO2 out. You might have to rethink and add CO2 when not exhausting. See how it goes.