May aswell explain the glheat aigns a bit also. Early mag deficiency can be mistaken for heat but when the serrations are spiked its usually a sign if heat stress and stress reduces light tolerance so when combined with folding is most often the heat causing light stress. Tgis happens fairly quickly once leaf/plant temps hit 78-82 depending on the genetics. Heat atress is almost always accompanied by light stress.
If the edges are rolled inwards and not folded then start looking for bugs… more specifically russet
or spider mites.
Tips curled down N tox.
Tips bleached/burned and upwards start of light burn
or potassium deficiency often seen in later flower when demand for K is high.
Now understand that all of these are symptoms of and rarely the cause…. Eg potassium scorched tips and serrations does not mean you need more potassium and likely its an availability issue like PH , nutrient ratio
or transpiration.
Figured since we’re are going deep on leaf signs i add some to it.