No changes done besides the plant sitting in a shaded area until temps cool down. The plant is still growing and the sun burn damage seems to be slowing down significantly.
That may not be burned from the sun. Is the 5 tsp per gallon correct? If so, dial back your nutrients to 50% of what the manufacturer states for their product. Flush before doing so to get rid of all excess nutrients in the soil.
@Tophat, it's sun burn there was one day that temps reach 115 and it was out in the sun. Since then the leaves dried out and shriveled up. If it was nute burn then all the leaves would have the same symptoms especially the lower leaves. The plant only gets 7ml of each nute once a week which is the max. The rest of the week I just add water and make sure plenty of water runs off.
We both my be correct in some way. If it's extreme heat we could dial the nutes back, protect her from the scorching sun with some shaded area that still receives light and see if she will recover. She is having to work extra hard now to compensate for the lost time since she is an Auto. Plus if her roots get too hot, she will run into root zone issues that may not be able to get fixed in enough time for harvest. I hope she recovers for ya!!