Kontender is bred by KWS.  It has done exceptionally well in UK, it was added to the UK list in 2012.  Over the last seven years exceptionally reliable.  It has an interesting combination of earliness and yield, similar to Kougar but it produces much better silage quality.  Kontender is vigorous in the spring, flowers and develops cobs very early, but dies back slightly more slowly creating a wider harvest window.