You may well be right danny - I looked up bedder in the OED and Chambers, and couldn't find it as a machine for carrying straw.
Just as a matter of interest what dictionary is that definition of bedder in?
Slaney, you'll find bedders advertised in the Farmers Guardian. The basic dictionary for the crossword is Chambers but words from the FG are deliberately used too. I (Chalicea) am trying to put some exclusively farming words in as often as possible (but always giving a secondary way of solving - via a double defiinition, as in this case, or by explicit wordplay). Happy solve!
Ahh ...thanks Ruthrobin. I was just randomly answering crossword questions without twigging that FG was Farmers Guardian, and the answer might have a bit of local colour.