Boron Deficiency?

Sorry … aber das ist ein Mega-Stickstoffüberschuss. Vergiss Bormangel. Das ist schon toxisch. Wenn es eine von 20 ist, schau Dir an wo sie steht. Wenn alle anderen Plants homogen wachsen … dann schmeiß sie raus. Dann hast du eine defekte Gen-Pheno erwischt.

Whoa—- never seen anything like this—- did you do an ipm or foliar? If not, I’m guessing genetics if all other plants look fine. Could be a weird pheno. Still looks a bit rich in nitrogen too.

Heat and water stress. Let ‘em dry out.

Looks like it's heat stress + sulphur def to me. If you have any Epsom Salt. Small 250ppm feed of that should help. As for the light green in the middle of the leafs. (That's just a mutation) Not boron.. you'd see like a goldish fade color that's boron and generally you only get boron if you using no ec water. Good luck.

I’d Genetics if it’s only 1/20 and all other plants are fine, is this one next to a fan? Nearer the light or heat source. .?

Nitrogen toxicity and small root issue ? ;) Could be too intence light added to first too, but could be not ... Maybe feed less ???? ;) Guessing it will be more ... I see signs of magnesium absorption issues too, slow down with feed, or it will progress. My personal guess.