Nos. 72-1598 and 72-1737. Argued December 11, 1973. Decided May 2, 1973. J. Mack Swigert, Taft, Stettinius Hollister, Cincinnati, Ohio, for The Kroger Co. by Stanley R. Zirkin, N.L.R.B. Marcel Mallet-Prevost, Asst. Gen. Counsel, N.L.R.B., Washington, D.C., John J.A. Reynolds, Jr., Director, Region 26, N.L.R.B., Memphis, Tenn., for N.L.R.B. Tom Gentry, Little Rock, Ark., J. Mack Swigert, Taft, Stettinius Hollister, Cincinnati, Ohio, for Plumbers, Steamfitters, and Pipefitters Local No. 155. Petition