Thanks for all the replies everyone.
White Birch Farm, I came across that same article that you posted above, prior to planting this past year and from the sounds of that article I was convinced that rutabagas were exactly what I was looking for too, and this year I planted several plots of rutabagas, some in April and some in May. They are so slow growing and never turned into much for us because the weeds took over. In my experience excellent weed control and a heavy dose of fertilizer are a must for rutabagas. . In late July this year we tilled some 4 year old white clover plots about an inch or 2 deep and broadcast PPT right before a rain and we got some bulbs of PPT as large as softballs (although most were baseball size or smaller). And that was without any fertilizer on the PPT plots. The PPT grow so much faster and are able to out compete weeds much better, Next year I plan to plant PPT in mid to late June, and fertilize heavily, to try and get the largest bulbs possible.