Since one boullion cube equals one teaspoon boullion granules, you would need to use 16 teaspoons, or 5 1/2 tablespoons of the granules for one third cup.
A single bouillon cube makes one cup (8 ounces) of bouillon. There are 32 ounces in a quart, so it would take 4 bouillon cubes to make one quart of bouillon.