Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Rodeo, Reward, Aquamaster, or ?? for Cutgrass during drawdown

My pond is drawn down 3 feet undergoing major renovation and repair of dam. I have a tall
grass growing in the exposed area. Someone identified it to me as cutgrass. I seek advice
on what to use to kill this: ROdeo, Reward, Aquamaster, 2,4-D, or something else??
There is a large price difference between these. Is is a matter of the least expensive
treatment?

You can see photos of it at:

http://members.cox.net/bassmaster/jul27index.htm

Thanks
Frank