Leaf edges folding

[therapeutic rtz]

Not sure what is cause these symptoms. It's not high heat my Temps are at 75 degrees and humidity 55-60% it's happening on random plants through out the garden with the edges folding up and yellowing on the edges. I've scoped for broad mites and russets. I use pure crop 1 every four days as part of my ipm. And i am growing in 70% coco and 30% perlite. And using athena nutrients. Anyone have any ideas. My only thought is possible overwatering so I'm going to let them dry back further. Any help would be appreciated.

 

[Creeperpark]

Moisture issue. When you water, make sure and allow for a small amount of water to discharge out the bottom to insure the whole root system gets wet. ..Then allow the top inch to dry well and the container to become light before watering again.

 

[troutman]

Maybe, raise the light a little to reduce the stress. Normally heat and low humidity causes leaf stress like that.
Some containers seem to hold water differently even when they are all the same which is why some plants are
affected and not all of them.

 

[Growenhaft]

these are leaf damage that occurs at the edges as a result of excessive evaporation. the leaf margins dry out, the leaf tissue contracts as a result of the loss of water, causing the leaves to curl up sideways. The cause is usually too high a salt content in the plant. or badly placed ventilation. As a result, an excessively strong air flow warmed by the light above the leaf causes the edges to dry out. but since the rest of the leaves also express nutrient problems, i decide that there is too much perspiration with a negative salt level between the medium and the plant. this means that the plant has to absorb more salts than it should in order to keep up with the salinity of the medium. lower the perspiration. check the salinity in the medium.

 

[Creeperpark]

The center plant has a wide gap between the substrate and the container, plus a lot of perlite. The plant on the right is well watered and the substrate is much darker. Transpiration is critical in order to move water through the plant from the roots to the leaves and then exit. Turgor pressure ensures that a plant can maintain its shape and when the pressure drops or rises too much, the leaves change their shape.

 

[TanzanianMagic]

filedata/fetch?id=17872734&d=1622941614
Not sure what is cause these symptoms. It's not high heat my Temps are at 75 degrees and humidity 55-60% it's happening on random plants through out the garden with the edges folding up and yellowing on the edges. I've scoped for broad mites and russets. I use pure crop 1 every four days as part of my ipm. And i am growing in 70% coco and 30% perlite. And using athena nutrients. Anyone have any ideas. My only thought is possible overwatering so I'm going to let them dry back further. Any help would be appreciated.

Maybe it is the Athena nutrients.

https://www.athenaproducts.com/

They're not specifically for coco. Canna, Plagron, Biobizz (in that order).

If I was growing in coco, I would:

1) Use coco only, no perlite
2) Slowly and thoroughy saturate the medium - and only water/feed again when the top of the coco is dry before the lights go on in the morning (plants take up/conserve a lot of water through evaporation from the soil)
3) Start with light bloom nutrients and epsom salt for magnesium - 0.4 EC (200ppm on the 0.50 scale) of bloom nutrients and 0.1 EC of epsom salt (50 PPM); pH nutrients to 6.0 (coco's pH) for the entire grow.
4) When the plant is half a foot tall, I would switch to the same light concentration, but of growth nutrients
5) Use R/O water with calmag; or use 1 teaspoon of in 1/4 gallon of R/O water, let it settle for a day and pour off the clean water, and add 3/4 of a gallon of RO water. This stops any magnesium deficiency when the first pre-flowers show up.

When you let the coco go a little dry between waterings, you have to use a lower nutrient concentration or you will burn the roots. However that also helps the taste of the final product, and is cheaper. Also, by giving bloom nutrients first, you're establishing a larger and healthier root system, which is also more efficient, which means, you can use lower nutrient concentrations.

If you let it go dry, use about 1/4 of recommended amount of nutrients, because coco can hold 40% moisture, and you can let it go dry to 10% - that's my rule of thumb. The concentrations increase as the soil dries, and burn the roots that way.