Chemical control of field horsetail (Equisetum arvense)

Abstract

Field horsetail is a perennial rhizomatous weed with summergrowing fernlike foliage and sporelating stems It likes moist freedraining sandy soils and gravel riverbeds and flood plains Glasshouse experiments on 10month old potted field horsetail plants showed excellent efficacy of imazapyr amitrole metsulfuron picloram and combinations of picloram with metsulfuron or triclopyr all at highest recommended rates However in the field trial single applications of these herbicides did not provide effective longterm control with significant regrowth 2 months after treatment This suggests that most of the herbicide treatments did not damage the extensive root system sufficiently to stop considerable regrowth with herbicides such as triclopyrpicloram glyphosate and metsulfuron failing to give adequate control of this weed in the field Further applications of amitrole or triclopyrmetsulfuron 2 months after the initial treatment gave better results but also killed all other vegetation