Herbicide responses of mat-forming weeds of forest remnants in New Zealand

Abstract

Tradescantia fluminensis, Plectranthus ciliatus, Asparagus scandens, Hedera helix, Lamium galeobdolon and Selaginella kraussiana are all mat-forming invasive species that limit regeneration of native plants in forest remnants in New Zealand. Experiments using potted specimens of these weeds showed that low rates (338-675 g/ha) of the herbicide triclopyr gave >90% defoliation of T. fluminensis, A. scandens and L. galeobdolon, but a higher rate of 1350 g/ha only gave 85% defoliation of H. helix. Diquat gave 85% defoliation of P. ciliatus. Aminopyralid was effective against S. kraussiana but was very slow acting. These experiments have identified herbicides and application rates for effective forest weed management to facilitate native plant regeneration in New Zealand temperate forests.