Peach is one of the challenging fruit trees to grow. They have several diseases and pest pressure.

What you have could be more than one issue. (The pale green leaves look like nutrient deficiency). The top picture could be bacteria leaf spot.

please google Penn State Extension, peach disease fact sheets. There is a lot of info for you.

Thank you! I'll do that.

I have the same thing happening on one of my peach trees (redhaven) that i planted this year (I also live just south of Omaha). So i have been keeping a close eye on it, about every two weeks i treat it with neem oil (I have had to use Seven and Pyrethrin to kill the beetles). So far, the color is still much yellower then i like, but it doesn't look any worse since i started treating. Since it was a fresh planing this year the nursery i got it from swears that i should not feed it until it has been in the ground for a full year (they also provide a 2 year warranty so i am willing to abide). Historically, we are not in a great location for peaches, i planted my first peaches last year, and both have gone through phases this year where they look stressed. But micro climates and being diligent gives me hope that they will thrive when fully established.

It is too hot in Omaha. The newly planted trees should be watered at least a couple times per week in this weather.