Line a 9x5-inch loaf pan with parchment paper or grease with cooking spray. Pre-heat oven to 350°F.
Beat together the brown sugar, vegetable oil, egg, vanilla, sour cream, and rum. Combine the flour, salt and baking soda in a bowl. Add dry ingredients to wet mixture and mix .Gently fold the in strawberries and rhubarb. The batter will be thick.