I just acquired a pasture and it has some real good bermuda grass in it . The problem is it also has weeds in it. I don't know the name of the weed but it is very common in Louisiana. It get's about 2 to3 ft. tall and looks somewhat like a tiny cedar tree. I know round up kills it becase i tried it in spots but also kills the bermuda. What would any of you recommend and also the rate of application.