[Cynthia, Prescott, AZ]

If this is only on one side of the plant, it could be recent sunburn. How long have the leaves been this way? Is it spreading up the leaf towards the plant? I would leave it alone for a while to see how it developes. If it were a form of bacterial infection, you would want to cut off the leaf before it reaches the bulb, with about an inch of clearence between the cut and the discoloration. Sterilized tool only for cutting into live tissue. If it is sun burn, it may enlarge just a little as the perifery tissue, which was also damaged, but less so, shows its nature. If it is sun burn, expect the spots to go black or a dry brown. Cynthia