Neither of those look like disease issues necessarily. Where are you located? And can you provide better photos of the two plants in question? The first looks like a camellia or similar broadleaved evergreen that has been subjected to sun scorch. The second is possibly a disease but could also be just an indication of some erratic or improper watering.

Identifying the two plants and where/how they are growing is really quite critical in determining what might be the problem with them and how best to fix.

Thanks! There should be any sun scorch issue. It has been raining continuously this winter for quite a long time. I'll try to get some more pictures to update this thread.

That's sun damage and it occurred months ago. It is not new.

Second plant looks like loquat seedling with some sort of fungal problem. Personally I'd not do anything. Maybe just remove that one leaf if it bothers you. It will very likely clear up when the weather improves. And could you give us your location please?

Thanks for all the great help! I'll see what will happen after the continuous rain stops.

I live in northern California (near San Francisco). Plants in above images are in my front yard facing east.