I don't think so. I think it is just sun scald. Were those seeds planted in the ground or were the plants transplanted to where they are? Have you had a lot of real hot, sunny days?
rainbow, they were planted in the ground and yes we've had a few really hot days, but mostly rainy days. (Northern Ohio). What seems funny to me, it has seem to affect only 2-3 rows out of several. I have some planted on the North side of my house and it really doesn't get much sun, except late afternoon. it's effecting a couple rows there too.
A very few of my bean leaves look like that too. I think it's just sunscald as rainbow said. Temps here have been mid to upper 90's with bright sun! Starting to get a little more humid now with a little lower temps. The summer rains are around the corner, hope they come!