Published online by Cambridge University Press: 12 June 2017
Aerial sprays of asulam (methyl sulfanilylcarbamate) applied at 3.4 or 6.7 kg/ha to forest plantations in western Oregon effectively controlled western bracken [Pteridium aquilinum (L.) Kuhn var. pubescens Underw.] without damaging Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings. Asulam also did not damage noble fir (Abies procera Rehd.) seedlings if applied without a surfactant. The half-life of asulam in forest soils ranged from less than 7 to 18 days and vertical movement in the soil profile was minimal. No herbicide residues were found in runoff water from treated areas up to 208 days after application.