hard to tell with just one leaf & no other details. The leaf looks nice n green, a bit of lighter area towards the tip. only because of the end & the spot in the middle would I GUESS it could be nute burn, but no one can know by just that leaf for sure. If u provide some more details about ur grow & better yet a pic of the whole plant, u will get a lot more help & replies
I found ur grow on the next page, WHY would you take the leaf off, uggh, NEVER remove the leaves if u dont have to. anyway, plants looks great, did u fertilize just recently? Was this the only leaf this was on?