Not sure about milorganite in the spring producing leaf streak.
https://www.daylilies.org/ahs_...
It is possible I suppose that milorganite might aid somehow in the spread, but I have not noticed it here. I seem to have more than my share of it with or without milorganite in the spring. It might cause faster growth of the foliage and maybe more tender foliage, and make it more susceptible to disease? I suppose any fertilizer might cause that.
