Checked this morning and it looks like the browning on the leaf edge has not advanced any further.
Got to thinking what else could have stressed the cuke besides over fertilization. Monday afternoon when it was not raining I had taken a trowel and dug around a small cuke plant next to the big that was shading the small one. The larger one is about four inches or so high and the smaller one is about one inch or a little taller. I transplanted the smaller one a little further away from the larger one. I thought I had read a week or so earlier that cukes needed to be direct seeded and not transplanted as cukes do not like to be disturbed once they germinate and sprout into seedlings. The digging around next to the big and small ones root system probably put stress on both of them causing the brown leaf edge.
See if they survive this episode.