Primisulfuron was evaluated in a series of trials over 5 yr for the control of bracken (Pteridium spp) and selectivity to 1 to 2 yr old radiata pine.Primisulfuron was slow acting and inferior to metsulfuron at 100 g/ha for the initial brownoff of existing fronds with no different effect between 50 and 100 g/ha.For the inhibition of rhizome regrowth 12 mo after application, primisulfuron at 75 g/ha was significantly better than 50 g/ha, and comparable to metsulfuron at 100 g/ha.Primisulfuron was selective to radiata pine when applied post-planting at rates up to 100 g/ha.