Oregon Forestry Pesticide Applicator Practice Exam

Cut-surface treatments rely on a systemic herbicide that can enter the exposed cambial tissues and move throughout the stump to prevent resprouting. Ester formulations tend to be less reliable on freshly cut surfaces because they don’t stay on the surface long enough for effective uptake, except in stumps cut only recently (1–30 days). The most dependable options for cut-surface applications are amine- or salt-form formulations of these active ingredients: 2,4-D (amines), triclopyr (amine), imazapyr, picloram, dicamba, and MSMA. These compounds are taken up through the freshly cut surface and translocated within the stump, giving robust control of resprouts across many species. In contrast, glyphosate in ester form is not the preferred choice for cut surfaces, paraquat is mainly a contact herbicide with limited translocation, and atrazine targets the soil rather than the cut surface, making them less effective for stump treatment.