The first thing I would do is price a new rod so you can make an informed cost analysis.
that's the best advice here. at the same time, check to see what replacing the entire cylinder costs too, that way you know how much a botched repair could cost. i'm not saying "don't weld" because i'm the type who will try a repair if i think it is practical and possible. i'm just saying to make sure it is worth trying.
i can't see from the picture, but it looks like the rod pulled away at the previous weld, which was only around the outside? was it only welded around the outside, because it looks like you have a flat in the middle where it didn't break because it wasn't welded there? maybe it would be possible to bore through the end of the yoke (or whatever part is broken off that we aren't seeing) and then plug weld to the center of the rod. you can reinforce that by welding around the perimeter of the rod where the break is. if it was only welded around the outside then they deemed that to be adequate (though in your case it didn't hold up), so i wouldn't lose sleep about not fully grinding the rod to a point. if you just clean up the mess from the break you'll have a blunt point with a partial bevel all the way around which should put you back to where it started, or even a little better.
the things i'd make sure to do are: fully extend or dismantle the cylinder. cover as much of the rod/cylinder as possible to avoid any extra damage (i use lengths of exhaust pipe, old wool blankets, layers of duct tape, etc). then grind down the broken area to a fairly smooth surface on both pieces. these are fairly obvious steps that you probably already knew, but i figured i'd mention them.
edit: after staring at the picture again (it's kind of like one of those pictures where if you look at it enough an image appears) it looks like the end piece is a sleeve for a cross pin. that means no luck on plug welding through to the center, so those ideas won't work in this case.
