scarlet runner bean leave curling and spotting
You can stop spraying. The leaf changes occurred because your plant ran short of water, perhaps during our recent session with higher than normal temperatures. During hot spells, container plants may need to be watered several times each day. Also helpful is to either move the pot to a shaded site during the heat or to rig temporary shade.
Runner bean plants can become quite large. Next time you plant them, consider using a much larger pot or, if possible, planting in the ground.