Cereal Rust Mites and Weeds in Timothy

So you got your nice stand of timothy, but come April, you're going to spray for cereal rust mites - Sevin XLR Plus being the insecticide to use. But what about mixing an herbicide in the same tank and spray for the mites and weeds in one pass?

Is this a no-no?

2,4-d and Sevin XLR Plus

or

Pasturegard and Sevin XLR Plus

or something else?

You folks mixing any herbicides with the Sevin?

FWIW - haven't found any labels that say it's OK - yet.....

Thanks,
Bill

Cereal Rust Mites and Weeds in Timothy