Sulfometuron was applied over the top of recently planted oak seedlings in three separate studies. Both preemergent (PRE) and postemergent (POST) timings were utilized in all studies. In 1997, six species of oaks were planted and evaluated, and two species were planted in the 1998 and 1999 studies. Sulfometuron was applied at rates of 0.1 and 0.2 kg ai/ha in 1997 PRE and at 0.1 kg ai/ha POST. In 1998 and 1999, treatment rates were 0.1 and 0.15 kg ai/ha for PRE and 0.1 kg ai/ha POST. Results indicate that sulfometuron is effective for competition control and can be applied PRE with total safety with the tested oaks. However, sulfometuron should not be applied POST over white oak seedlings, as mortality will result.
