Curling leaf problem, help pls

[Thighland]

One of my plants has leaves turning up, as can be seen in the pic. The plant is still growing ok. All other plants in the tent are fine. They are getting enough water and nutes. Temps in the tent are 80 to 85, humidity 80 to 90%

 

[exoticrobotic]

Plants look good to me, a touch under fed, but you need to lower your humidity.

90% is too high It should be around 60%

How often are you watering?

 

[Thighland]

Thanks. The pic is deceptive, they are actually a dark green and not under fed. Now I am watering every other day. Unfortunately I have no control over humidity, as I'm not using AC and in the tropics. It will drop when the rains finish in about a month.

Back to the problem, if you look closely you can see the leaves have turned upward and inward. It doesn't seem to be getting worse, but not better either.

 

[VenerableHippie]

Not an indoor grower but when I see plants doing this I think drainage, overwater. I see it's close to a wall. Hotter there? Reduced airflow there?

 

[Thighland]

Thanks. It's not hotter there. The potting mix has heaps of rice husks, so excellent drainage. Although I can hold back watering the single plant and see if it improves.

 

[VenerableHippie]

Thanks. It's not hotter there. The potting mix has heaps of rice husks, so excellent drainage. Although I can hold back watering the single plant and see if it improves.

Now I 'm wondering how much water those husks hold and them being close to the stems. No chance there's rapid decomposition in the pots? Which can look like overwater.

 

[Creeperpark]

Heat stress. Move your plant to the edge of the grow instead of the center.

 

[Thighland]

Thanks, I'll raise the lights as I've already moved it to edge. That's about all I can do.

 

[exploziv]

High temp and RH makes it really hard for plants to cool off and move water and nutes through them. Can't you add more ventilation so at least the RH drops??

 

[Thighland]

High temp and RH makes it really hard for plants to cool off and move water and nutes through them. Can't you add more ventilation so at least the RH drops??

No, the fans are already sucking the sides in, besides, humidity is the same outside the tent.

 

[troutman]

Humidity high like that will cause mold eventually.

 

[exploziv]

Does that mean you are venting from an unvented space, or what? You need fresh air in, always. Add more intake, if sides sucked in but notenaugh venting...

 

[Thighland]

Troutman, the humidity will ease with the end of the rainy season. In this part of the world it pours for 6 months and is dry for 6. Very heavy rain for the past 2 months. Anyway I plan to move the plants outside for flowering.

Exploziv, there is plenty of ventilation, humidity in the tent is about the same as that outside. Difficult to dry the washing!

 

[BumblebeeTuna]

I'm betting on potassium. I've started having weird leaf symptoms ever since switching from Walmart nutes to "jackem up coots" style mix. Where exactly is the potassium in that mix? All the soil recipes are thrown together by uneducated hobbiest with no basis in reality. Cannabis is such a mutt you will get a dozen different symptoms of the same problem from a single pack of seeds.

The last time "the fold" happened I was deficient in calcium and phosphorus, and now that I think about it, the leaves did not turn up until I used the max dose of a liquid calmag product, which turned my tips white (potassium antagonized by calmag).

If you look close, you'll see these tips are folded up, and white. The plant outgrows "the fold" after transplant...


Then it sets back in once excess lime is soaked up..

This is nothing but canoeing; by light sensitivity, due to potassium deficiency. Cannabis struggle significantly to uptake potassium in the presence of excess Calcium, according to light scientist Bruce Bugbee. Bruce also states plants should be green, not blue red purple or yellow, and that blaming the light is like blaming the engine of your car for having blown tires:





Every plant I've harvested with canoes, the leaves were dull, colorful, crispy, and the buds were mids. Every plant I've harvested without canoes, the leaves were soft, shiney and wet feeling, light green, and the buds were high-grade.

Light sensitivity is undeniably Potassium deficiency.

I'm just gonna say it.. The worst growers always have the best weed. Not because they grow old noname seed their neighbor made long ago, but because they use simple inputs that don't lock out Potassium, the quality molecule. And they use finisher recipes with sulfur and potassium to mobilize sugars, flush excess nitrogen that lowers sugars and oils, trace minerals and a dark period to convert excess nitrogen to proteins and starches to sugars, hang the whole plants upside down so the plant keeps mobilizing sugars, all that wives tale stuff we are told not to do today.

My weed has gotten progressively worst the more I read organic grow forums or watch broganic potcasts. Nothing but a PK deficit cluster fuck. But at least my crusty sea salt hippy mids are purple??

Ismail Cakmak – Sabancı University

 

[GMT]

It's also worth just making sure nothing is making a home in those curled leaves.

 

[Armate Otro]

High temp and RH makes it really hard for plants to cool off and move water and nutes through them. Can't you add more ventilation so at least the RH drops??

But if it's 80 temp and 85% RH, wouldn't that be in the proper VPD range?

 

[exploziv]

Yeah, it should work for veg at those numbers, but only if the air is fresh and you got enaugh air exchange. Not enaugh ventilation could be your problem if by the rh being same as outside the tent means you are reusing air from the room you vent in.