Published online by Cambridge University Press: 12 June 2017
Listed on the basis of visual ratings in Sept. 1961, in the order of increasing toxicity to Kentucky bluegrass sown in April, 1961, and treated May 31 and June 6, the herbicides were 2,3,5,6-tetrachloroterephthalic acid (DCPA), amine methylarsonate, diphenylacetonitrile (diphenatrile), calcium propylarsonate, disodium monomethylarsonate (DMA), N,N-dipropyl-2,6-dinitro-p-toluidine (dipropalin), calcium arsenate, O-(2,4-dichlorophenyl) O-methyl isopropylphosphoramidothioate (DMPA), polychlorodicyclopentadiene isomers, and alpha, alpha, alpha-trifluro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). All herbicides except DCPA and DMPA (liquid) persisted after two years of use until March 1963 in the top 2 inches of soil.