Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Non-triazine herbicides with residual activity for weed control in newly planted farm woodlands: safety and efficacy of a range of agricultural and horticultural products.

Abstract

An experiment was established, on a heavy clay soil at Drayton, Warwickshire, UK, to evaluate 8 commercially available agricultural/horticultural herbicides (terbacil WP, linuron SC, isoproturon SC, metsulfuron-methyl WG, metsulfuron-methyl + thifensulfuron-methyl WG, trifluralin EC, diflufenican + isoproturon SC, diflufenican + trifluralin SC) for potential use in newly planted farm woodlands. Each herbicide was applied at 2 rates over 6 tree species (Quercus robur, Fraxinus excelsior, Prunus avium, Acer pseudoplatanus, Betula pendula, Pinus nigra var. maritima). All treatments were assessed for both safety to trees and effectiveness in controlling weeds. Results were affected by an exceptionally dry growing season, but the phytotoxicity to Betula pendula and Prunus avium of some herbicides with current off-label approvals for use in farm woodlands was clearly demonstrated. Only metsulfuron-methyl gave useful levels of early-season weed control. Products tested were less effective than triazine herbicides, such as atrazine or terbuthylazine, used in previous studies.