Sorry to see what your plants are going through. I'll give you a more lengthy reponse. Cercispora is unlikely to be the problem. While I see some in that picture, that fungus is literally everywhere. Just about every plant that is vulnerable to it in the world is infected with it, but it is generally not a major problem. Healthy plants live with it, and only see blooms of it when something else, usually environmental, is wrong. Looking at the picture, it does look like some old sunburn is there on the older growth, or if this is a sudden change, I would wonder if the roots are compromised, and you are seeing leaf dieback as a result. Sent from my iPhone using Tapatalk