Biology and control of pypgrass

Abstract

Pypgrass (Ehrharta villosa) is an invasive rhizomatous grass weed which is smothering the native dune flora at Turakina Beach, near Wanganui. A deep rhizome system, sunken stomata, in-rolled leaves and a mycorrhizal association contribute to the aggressive nature of this weed in the dune community. A field trial showed that haloxyfop will successfully control pypgrass; successive applications give best results. Several other monocotyledons from the dune community were shown in a pot trial to be unaffected by haloxyfop. Studies of pypgrass biology suggest that, although vegetative spread is aggressive, establishment from seedlings is poor. Eradication should be an achievable goal.

Grazing capacity change on a small Mediterranean-type South African offshore island following the control of invasive alien European rabbits ( Oryctolagus cuniculus )

“…Ehrharta villosa can withstand drought conditions (Rudman 2003) by using its deep root systems to access water from deep below the soil surface (Harrington et al 1998). Additionally, E. villosa does not depend on seeds for reproduction, survival and spread (Hodder 1997).…”

“…This explains why the grass reached its upper equilibrium in the second year following rabbit control. Ehrharta villosa is an aggressive competitor whose long stems (often growing to a height of two metres or more) allow it to grow over and overshadow competing vegetation (Harrington et al 1998).…”

“…Ehrharta villosa plants can withstand drought conditions because of their deep roots (Harrington et al 1998) and ability to regenerate from rhizomes and rhizome fragments (Hodder 1997).…”