Yellowing pumpkin leaves; no bug/fungus present?

[muffymink]

I live in Seattle WA and decided to plant Dill's Atlantic Giant & Cinderella Pumpkins.

Pumpkins were looking healthy until this last few weeks.
The leaves are yellowing, some of them have brown chunks missing? I've been cutting away the dead stuff,

The pumpkins do have flowers coming in and new leaves

But I need to know if what I'm experiencing is normal or pest/fungus related?

They are fertilized 5-15-15
I water regularly and miracle grow every couple weeks.
I have not found any bugs or beetles eating on the plant and have been spraying a organic pesticide just in case.

The pumpkins will be moved to a different container once they are bigger but for now they are here to keep the rabbits away.

[Lindsaylew82]

That pot looks small. They could definitely benefit from more potting soil underneath them. Do you have somewhere you can plant them in the ground? Squash bugs are really hard to see sometimes, but in my experience, they come out of their hiding after a really good watering. They come out and I drown them in a cup of soap water. I also use neem oil as a prophylactic against fungi AND squash bugs. It needs to be sprayed very late, almost dark. Look on the underside of the leaves also, their eggs look like this.

[Lindsaylew82]

I don't know why it won't load the correct picture.. That's powdery mildew though.... Lemme try again...
nope...
Idk... Anyway...Look out for clusters of tiny pearly white to deep orange eggs on the backs of the leaves.