It's probable that you have lost it to the hard winter. Did you tie the fronds together and fleece it last year before winter? I thought I had lost one of mine through not giving it sufficient protection against a foul winter but fortunately a Pampas that was by its side was kind enough to droop all over it and help. About 6 weeks later than usual it is now producing crosiers (baby fronds) but it was touch and go. I would water and feed it, as usual, down the centre, and give it a few more weeks. You don't say how old it is or how large the 'trunk' is, but I fear it is gone.