If your weeds are much over 6 inches tall..I wouldn't spend money on another tool..I'd spend money on a second pass. Even a disc won't take out lambsquarter and pigweed that are 8 inches tall in one pass...and if they survive..you better have a plan to tackle them..because Roundup won't take them out. I've found as little as a quarter pint of 2,4-D ester in a pre-emerge will burn those weeds off...but waiting till they get their legs back under them..and trying to control them when the rest of the field needs post sprayed is iffy. If you do have lambsquarter and pigweed escapes...you might try adding some Harmony (I can't remember the exact name of the soybean post product.) It will really spike the effectiveness of the Roundup up.
