Merion Kentucky Bluegrass Response to Soil Residue of Preemergence Herbicides

Abstract
Preemergence herbicides were applied to lawn turf on a loam soil in April, 1963. Polychloro-dicyclopentadiene isomers, N-2-mercaptoethyl benzenesulfonamide (bensulide), calcium arsenate, l, 2, 4, 5, 6, 7, 8, 8a-octachloro-4, 7-methano-3a, 4, 7, 7a-tetrahydroindane (chlordane), dimethyl 2, 3, 5, 6-tetrachloro-terephthalate (DCPA) 0-(2, 4-dichlorophenyl)-0-methyl isopropylphos-phoramidothioate (DMPA) and 2, 6-di-tert-butyl-p-tolyl-methylcarbamate -(terbutol) were included. Soil of the respective plots were sampled from 0 to 2- and 2 to 4-in depths in December. These soils samples were used for planting plugs of mature Merion Kentucky bluegrass. The cultures were grown for 18 days in the greenhouse. Twenty-three in. of rain had fallen between the treatment and sampling dates. Yet root growth was seriously reduced in the soil from the 0 to 2-in. depth that had received terbutol and bensulide. Several chemicals gave significant reductions in topgrowth. Preemergence herbicide residues had sufficient influence on Kentucky bluegrass type lawn turf to justify specific study of each chemical with regard to this factor before widespread use.