Probably just heat stress and a little daylily streak. You can trim the bad leaves if you want.

I will do some trimming

I agree with Mantis. If you'be been getting a lot of rain, it may be leaf streak. If this is a new plant, it's not unusual for the old foliage to start browing and dying. Trim it a bit, and it should be fine.

Debra

If you give a sharp tug to old ratty looking foliage it should come right off at the main body down at the crown. If you tug and it is fairly resistant to coming off it means it's not ready to detach from the main plant yet. Leave it alone and try again later. Leaving lots of short broken off leaves down near the crown invites pests to nestle in between the old and new foliage and water to accumulate. Best to clean the old brown leaves out by stripping them away from the crown just as you would snap a stalk of celery from the main body.........Maryl