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Providing evidence to improve practice

Individual study: Partial chemical control of New Zealand pygmyweed Crassula helmsii at Holmsley Wildlife Reserve, Hampshire, England

Published source details

Stone I. (2002) War against Crassula – one year on. Enact, 9-10


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Crassula helmsii: Chemical control using herbicides Control of Freshwater Invasive Species

A before-and-after trial at a single waterbody in a nature reserve in 2000-2002 in Hampshire, UK (Stone 2002) reported that treatment with diquat and glyphosate herbicide nearly eradicated C. helmsii, although no statistical tests were carried out. The treatment cleared 98% of C. helmsii from the lake, and ‘no major regrowth’ was reported two years after treatment. The diquat-based herbicide Reglone was applied at 50 l/ha in March 2000, and again at 35 l/ha one month later. The glyphosate-based herbicide Roundup was sprayed onto vegetation around the edge of the lake in November.

 

Crassula helmsii: Use lightproof barriers to control plants Control of Freshwater Invasive Species

A before-and-after study in 2000 at a single lake in a nature reserve in Hampshire, UK (Stone 2002) reported that covering with black sheeting killed C. helmsii, although no statistical tests were carried out. Black sheets (20 x 10 m) were secured tightly over submerged and exposed areas of C. helmsii for six months including summer. Few details of the site or methods were provided.