What’s happening to my plant?

[Tats]

Yellow splotches are appearing on the fan leaves mid way up the plant. It doesn’t start at the tip, typical of nutrients burn. Could it be the heat? It’s outdoor in an extremely humid environment and during the day it can get into the high 80’s sometimes 90’s. Could it be nitrogen deficiency? Pics below. Any feed back would be greatly appreciated.

 

[Flint_Fredstone]

add some nitrogen, make sure it drains well and don't over-water

 

[Jimster]

Looks like either an advanced magnesium deficiency or lockout... or bugs. Any idea of soil Ph? The temps and Rh are kinda high but shouldn't cause any problems like you are seeing. The upturned leaves is also a sign of something other than light stress but I can't remember the cause. Short term memory loss!

 

[Beachwalker]

WPM & Bugs