Saltcedar (Tamarix spp.) Management with Imazapyr

Abstract

During the 20th century, naturalized saltcedar has become common within major tributaries throughout the western United States. Often growing in nearly monocultural stands, saltcedar is suspected of lowering water tables, thus destroying wetlands and wildlife habitats. Management efforts have primarily relied on mechanical and cultural practices, but recent success in controlling saltcedar with imazapyr has led to wider herbicide use. Based on a number of research/extension field trials in New Mexico from 1987 to present, imazapyr applied alone or in combination with glyphosate was found to control saltcedar to levels of 90% or greater, especially when applied in August or September. For fixed-wing aircraft applications, we recommend applying imazapyr at 1.1 kg ai/ha or imazapyr plus glyphosate at 0.56 plus 0.56 kg/ha. For individual plant treatments, we recommend spraying the foliage to wet with imazapyr at 1% v/v in water, or imazapyr plus glyphosate at 0.5 plus 0.5% v/v. Herbicide activity may be reduced as saltcedar height and stem number increases.