PORTLAND, ORE. — John Tucker, former president of Turtle Mountain L.L.C., a natural foods company, has been named chief executive officer of Dave’s Killer Bread, a maker of organic, whole grain, vegan and bioengineered-free bread products sold throughout the Western United States. He succeeds Shobi Dahl, who will move into a support role, though he’ll help Mr. Tucker with the transition. Dave Dahl, who created the bread line, remains president. Mr. Tucker started his career in quality assurance, quickly evolving into research and development and product innovation with companies such as Weight Watcher’s, Kraft Foods and H.J. Heinz Co. Eventually he broadened into marketing and business development with Turtle Mountain. Mr. Tucker’s appointment takes effect May 13. Separately, Dave’s Killer Bread added Walt Freese, former c.e.o. of Ben & Jerry’s and Stonyfield Farm, to its board of directors.