You need to post that video on FB... I'm certain others would be enthralled
I remember that potassium aids plants in converting harmful free radicals formed from incomplete photosynthesis, during cold weather. I may have seen damage like this on some succulents, where the leaf never really froze, but strange discolorations and mottling appeared after the episode... on no! Have we stumbled on another theory for Agave enigma? Free radicals from incomplete photosynthesis?? How's about another KNO3 experiment?
I think Tim could be right about DMSO. The KNO3 with DMSO, even high enough concentrations of KNO3 alone, could induce plasmolysis in the cells. If anything positive does result, it may be from DMSO alone... possibly allowing cells to release some internal pressure. If excess internal CO2 is the problem, more permeability and diffusion of gas aside from the stomata should be expected. But what's the residual effect of the treatment? Let's try it anyway. What's the worst that could happen... a few dead plants?