Nutes, heat or??

Growing outside in FFOC. Only used 1/4 solution of Big Bloom and Grow Big twice. 3 gallon pots, temp at 100 today. Everything is PH balanced. Edge is curling and yellowing and it looks white and gooey on the veins on the nderside of the laef..seeing it on another leaf as well. No signs of insects

I think that may be heat stress, but not positive. Ideals temps for MJ are in about the 65-80 degree range.

Hi babe, 100!!! Phew, thats boomin hot eh?
Im not sure if the yellowing is due to the heat as i dont think the plant would show signs ov heat stress quite so quickly. Also not sure if youve overdosed on Nutes either, unless the compost still has lots ov fertiliser in it and even then 1/4 strength should be fine...
Maybe the water youve been using is quite "hard" (high PH)...
This glupy stuff on the undersides ov the leaves is very strange... Maybe the plant is sweating out some Chalky/Salty deposit that is being diluted by water molecules, turning it into a paste...
Possibly, theyve been damaged very lightly by a grazing snail and its sap produced by the plant to try to repair the damaged section...
Im a gardener as a profession but dont think ive come across this before...

Keep an eye out and see what develops... If in doubt, remove the affected leaves and burn, dont compost them.
Good luck babes
Keep me posted as im interested in what it is...
Xxx
Try wiping it off with a moist cotton bud and see if it appears again

So far it's only on one plant. The pic here is of the top fan leaf, I see it happening a bit on the bottom fan leafs. Just ran another gallon of water thru the pot on the assumption it's nutes. The other plant from the same mother shows no signs of it tho

I had that happen on a warm day with one of my GDP's last season. It was a hot day, I had just added nutes the night before and the pot was fairly dry when I noticed it. It may be a combination of the heat and nutes but I can't say for sure.. She will pull out of it though. That leaf may end up dying off on you but don't cut it until it's gone for sure.

Seeing it now on some lower fan leaves so I ran a hose thru the pots for a few minutes. It's looking like brown rust so pretty sure its nutes , but i rarely feed and less than half the recommendation. Am knocking on wood!

Leaves already affected are dry/brittle where the "burn" marks are, but looks like a good flush stopped any more damage.

I have 4 different strains, only the pre '98 Bubba had an issue. It's odd, last year I used the full amount of FF nutes and only had one minor burn issue (from feeding too often). I'm using less than half here. These puppies are 1-2 feet tall tho, so maybe they aren't big enough