Can ultra violet light damage or kill plants? The deformation of the top leaf of this seedling I think is caused by to high UV level. UV level 8 is max for this plant. I have a UV reading of 11 today it wiil get as high as 13. I will cover with sun screen until the end of July. I had this problem last year and discovered plants can recover and grow around the damage.
Lat: 31.8595°N Lon: 110.07667°W Elev: 4580ft