I'm having great success killing everything using 1oz per gallon glycophosphate (Cornerstone plus) along with 1 oz per gallon 2,4-d, (standard % but I don't recall brand) with 1/4oz per gallon surfactant. Mix surfactant with the water first, then add the 2,4-D then finally the glycophosphate. Based upon hours of internet. LOL
We bought 1.7 acres last year (May) and I could not keep up with the weed infestation, perennials and annuals, left for us last summer. Hitting them hard now and digging the mix above. Knocks cheat grass on it's ass.
Ones for emergent vegetation one's for the roots. Both work when plants are in their growing phase.
Actually, both are systemic. They are absorbed by the vegetation and carried to the roots. And both work on any suscecepticle green plants at any stage of growth.
Though an annual application can be most efficacious during the bolting stage. (rapid stem growrh).
A surfactant is used as a wetting agent, to actually get your chemical past a fuzzy or waxy surface and into the pest's cells. I actually find it to be a waste of money in most cases. That would depend on your target pest.(weed)
While I see anecdotes of 2-4 D use on very young, emergent cheat, as well as other grasses. It is not really a recommended use of the product.
While Roundup is the product currently in the news and the one being targeted by the globalists at this time. 2-4 D is actually much more dangerous to mammalian life forms, and is also much more prone to volatilise and drift to nontarget areas.
We call the 2-4 D/Roundup mix feel good spray, because it feels good to see those broadleafs wilting away within a couple hours. But actually, the broadleafs would be just as dead within a week or so if you just hit them with the Roundup.
As to controlling your cheatgrass, the most effective method is a preemergent. I like Krovar, there are others. Krovar is often mixed into lawn weed and feed by commercial applicators. And it is used between the rows in orchards. Krovar does not harm your existing mature plants, but prevents germination of new seed. One application of Krovar in the late fall, or very early spring will eliminate cheat grass, kocia, dandelions, etc through the following summer. I like to apply it over the snow in late Jan or early Feb. One application and done for the year. No RU or 2-4 D needed.
But what do I know. I only carried a commercial applicator's license for sixteen years, along with the 12 to 16 hours of annual recertification training. And during that time kept 300 acres of commercial bare ground weed (and grass) free, at minimal cost in materials and labor.