Published online by Cambridge University Press: 12 June 2017
Dicamba (3,6-dichloro-o-anisic acid), 1,1′-dimethyl-4,4′-dipyridinium ion (paraquat), and (2,4,5-trichlorophenoxy)-acetic acid (2,4,5-T) were applied as foliar sprays to 4-year-old sweetgum (Liquidambar styraciflua L.), green ash (Fraxinus pennsylvanica Marsh.), water oak (Quercus nigra L.), and loblolly pine (Pinus taeda L.). For the three hardwood species the amount of herbicide absorbed and translocated, as measured 4 days after application, was correlated closely with tops killed 1 year later. Applications in May were more effective than those made later in the growing season. Loblolly pine was defoliated by all herbicides but recovered the second season after spraying.