What deficiency is this margin curl?

[BumblebeeTuna]

I know this is a nutrient imbalance because it only happens with certain batches of soil. Leaf temp is 75°, vpd is great. Lights at 50%, 20". Growth rate is normal. Plants smell normal. About 50% of plants have this lobe curl. It's obviously not a light/heat issue.

This run has obvious phosphorus and calcium deficiency (forgot to add SRP to seedmix tub). Is it related to either of those nutrients? Potassium is fine. Nitrogen is fine. Is it some micronutrient?




Some runs, the entire leaf is folded, not tacoed but folded like 2 book pages. I'm assuming this is the same issue? (can't find a pic)

 

[Creeperpark]

It may be a calcium imbalance. Make sure you have a nice breeze blowing over the plants to transpire the calcium from the soil. When those leave curl like that they are having problems transpiring out the stomatas'. Remember the only way a plant can move calcium is by transpiration. If I have a plant showing calcium deficiency and have plenty of calcium in the water and soil it is because I lack enough air movement for transpiration.

 

[BumblebeeTuna]

My environment is good, fans gently shaking the plants, but seriously lacking calcium. I'm going to add more Gypsum before transplant and see what happens.

 

[Creeperpark]

Sounds like you know what you are doing but be careful using gypsum in small containers.
Over-application of gypsum can strip essential nutrients from your soil, and this can harm plant growth. Google

Is gypsum good for potted plants?
depending on how big your pot is. Gypsum helps to flush out the built-up minerals and adjusts the pH of the soil.

It is possible to use too much gypsum. Adding too much gypsum to your soil can damage it by removing necessary nutrients. An abundance of gypsum can remove elements such as iron, aluminum and manganese from your soil and cause them to contaminate other areas, harming plant growth. Google

Good luck. Keep us posted

 

[Thcvhunter]

You can put a tray under you containers when watering in gypsum. Then re-add the water that floods out. This will reintroduce the minerals the gypsum flushed out.