I agree that it has some or alot of red mulberry in it. Why the fruit are swelled up, I don't know. Alot of rain there?

Those are the female flowers. They will form fruit if pollinated. The 'normal' looking fruit are the ones which have already been fertilised.

ETA beesneeds answer is far better.

What characteristics make you guys think there is some Morus rubra in this tree? The fruits aren't unusually long, and the red fruits can be Morus alba var. tartarica? Do the tops of the leaves feel rough? Is there pubescence on the leaf undersides? I think the beige color is normal in the transition to red. Morus rubra would be more densely branched. Did you taste a berry? Morus rubra leaves are less lobed than Morus alba.

Ah yes, Popcorn Disease!

"Popcorn disease of mulberry is caused by a fungus (Ciboria carunculoides). It occurs in late spring and early summer. The white mulberries are more susceptible to this disease. The disease manifests on the developing carpels and looks like popcorn kernels. It is a serious disease if the tree is being cropped for commercial purposes; however, it does no harm to the overall health of the trees"

And the leaves have semi-long tails and somewhat of the classic, large, ovate shape of Morus Rubra. But, they are a little more heart/teardrop-shaped, smaller, and fairly glossy on top like Morus alba.

Whereas pure Morus rubra has more leathery leaves with an "embossed," matte look on top:

I think your judgment is correct, blakrab. I show what I think is also a hybrid -- leaves huge and rather fuzzy, but not embossed like pure red mulberry.

^ Yea, that one definitely has more of the characteristically large, ovate leaf shape of Morus rubra. Although some of the leaves seem to taper too much. Also they do look a little glossy, and maybe flat to be pure, although these borderline cases are always hard for me to guess? So my guess would be that it does seem to be majority Morus rubra...but with maybe a little Morus alba?

Here's some close-up pics of a pure Morus rubra. When you see a real one like this, there is no question. Notice how the top surface looks like a raised, aerial map of a subdivision. Morus alba & its hybrids never have that.

Now go back and compare these pics to the original pics...and you can see why the original is def NOT a pure Morus rubra!

You might want to start clearing the affected fruit off the tree now instead of waiting for it to drop. It can be easier to pick a fruit than it is to clean it up off the ground.