I found a recipe for parsnip-pecan Cake (not bread, but these things are subjective) in Marian Morash's Victory Garden Cookbook, so perhaps it is what you remember.

1 10" Tube pan/Preheat oven to 325 degrees F

Thoroughly combine oil and sugar. Sift together dry ingredients and add to oil and sugar, alternating with eggs. Beat well after each addition. Mix in parsnips and then pecans. Pour into buttered tube pan. Bake in preheated 325 degree oven for 1 hour and 10 minutes. Cool in pan for 10 minutes before removing.