If you like granulars and not able to use liquids you may want to try Navigate (gran 2,4D). Many of the herbicides sold in cans or bags you see in magazines for killing weeds off your dock are made from 2,4-D. Just know it won't kill any monocots(grass-like plants) same as your lawn and dandelions. Consult the label for recommended rates. We use liquid 2,4-D for large scale milfoil treatment bids here in Indiana. It works fine but you have to make sure you have the correct equipment for application. Take a look at Navigate in the 50# bag for coontail. Its made by Applied Biochemists which is a great company and has been very helpful to us over the years. Also make sure you don't need a permit. I don't know the rules in Nebraska.
http://www.lonza.com/~/media/Files/water-treatment/Navigate.ashx?la=en
http://www.cdms.net/ldat/ld4JS003.pdf
