Published online by Cambridge University Press: 12 June 2017
Japanese honeysuckle (Lonicera japonica Thunb. # LONJA) vines can smother young trees, presenting problems in nursery, parkland, and woodlot management. The tardy-deciduous nature of honeysuckle provides an application window for its selective control with glyphosate [N-(phosphonomethyl)-glycine] or dichlorprop [(±)-2-(2,4-dichlorophenoxy)propanoic acid] plus 2,4-D [2,4-dichlorophenoxy)acetic acid] immediately after fall defoliation of hardwood species. Glyphosate at 1.5% v/v (5.4 g ae/L) applied in December killed mature, woody honeysuckle vines and eliminated most regrowth from basal and subterranean buds 28 months after treatment. Dichlorprop plus 2,4-D at 1.5% v/v (3.6 g ae/L of each herbicide), when applied shortly after the first freezing temperatures in October, was as effective as glyphosate but was less effective when applied in December. Tuliptree (Liriodendron tulipifera L.), American beech (Fagus grandifolia Ehrh.), and Scotch pine (Pinus sylvestris L.) suffered minimal and temporary injury from these herbicides.