It's been so long since I used it that way that I don't remember. I use 8 to 10 oz per acre when spraying chufas and that always works ok. If you put it out now while the grain is relatively short I would think that would be enough. The taller it gets, the more it will probably take.

I'd suggest looking at the label or talking to someone with more recent experience. Maybe someone will come along in this thread soon