Control of aspen poplar, balsam poplar, prickly rose and western snowberry with metsulfuron-methyl and 2,4-D

Aspen poplar, balsam poplar, prickly rose and western snowberry species grow together in pastures of the aspen parkland and reduce the grass and forb production available for grazing. Two 7-yr studies were conducted in east central Saskatchewan to evaluate metsulfuron-methyl (metsulfuron), 2,4-D and a mixture of metsulfuron + 2,4-D for the long-term control of these woody species. Metsulfuron applied at 60 g a.i, ha(-1) effectively controlled the four woody species for 7 yr. Control was not improved when 2,4-D at 2 kg a.i. ha(-1) was added to the 60 g ha(-1) rate of metsulfuron. Aspen poplar control was improved when sucker regrowth was 2-yr old rather than 3-yr old. Grass and forb production was increased 50% from 1023 kg ha(-1) in the untreated areas to 1619 kg ha(-1) following application of 60 g ha(-1) metsulfuron in two experiments averaged over 5 yr. Forbs production decreased from 44% on the untreated area to 8% on areas treated with metsulfuron.