What do I have here

I planted a sorgum/sudan hybrid for cattle feed. In the lower areas (where pooling could occur) I have the stuff on the left. It is a ridged triangular stalk to a pointy seed head. The thin leafy part is deep V and ridged as well. The right appears to be (I hope) the crop. About pencil size stalk with nice broad leafs. In the better drain areas it about 5' tall down to about 2' where the other stuff is prevalent. My concern is I was told not to cut it under 20" due to harming the cattle (acid content). But the stuff on the left is only about a foot to 15" tall and turning yellow. What is it? Could excess moisture cause the seed to mutate? Bad / contaminated seed. This field was pretty clean, grain crop last year. So I am pretty sure it was planted as I haven't found any thing like it out side the planted area. Plus I may have planted it a tad to deep.

• Yellow Nutsedge

What are you planning to do with it? If you are going to chop it and put it in a silo, I wouldn't loose any sleep over putting the short stuff up with the rest.

As far as the grass, it ain't what you planted.

Donovan from Wisconsin

It will grow wild in wet areas. It has nothing to do with your sorgum/sudan grass. It can be hard to kill, but Roundup will kill it, along with everything else.