Growth Retardant Effects on Three Turfgrass Species

Abstract

Abstract ‘Baron’ Kentucky bluegrass ( Poa pratensis L.), ‘Kentucky 31’ tall fescue ( Festuca arundinacea Schreb.), and ‘Reliant’ hard fescue ( Festuca ovina var. duriuscula L. Koch.) were treated with N-[2,4-dimethyl-5-[[(trifluromethyl) sulfonyl] amino] phenyl] acetamide (Mefluidide) at 0.28 and 0.56 kg/ha, (2-chIoroethyI) phosphonic acid (ethephon) at 2.24, 4.48; and 6.72 kg/ha; and 5-(4-chIorophenyl)-3,4,5,9,10-pentaaza-tetracyclo [5,4,1,0 2’6 , 0 8,11 ] dodeca-3,9-diene (BAS 106 00 W) at 1.68, 3.36, and 5.04 kg/ha. Similar responses to all rates of mefluidide and BAS 106 00 W, and to the 2.24 kg/ha rate of ethephon were observed for Kentucky bluegrass and hard fescue. Tall fescue shoot growth was reduced by mefluidide and the BAS 106 00 W, but to a lesser extent than the other 2 species, and was not affected by ethephon. Ethephon elongated internodes and shortened leaf blades of Kentucky bluegrass. Ethephon at 2.24 kg/ha reduced Kentucky bluegrass clipping weight and increased root organic matter production without reducing quality.