Action: Crassula helmsii: Use liquid nitrogen to kill plants
- We found no evidence for the effects of treating Crassula helmsii with liquid nitrogen.
'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.
Liquid nitrogen (-196 °C) can kill vegetation by freezing, and has the advantage that no harmful residues are left in the environment. It could therefore be used for targeted treatment of localized patches of C. helmsii. However, a small trial suggested that only parts of the plant that came into direct contact with liquid nitrogen were killed (Leach & Dawson 2000, no data given). Dense mats of C. helmsii are therefore likely to insulate all but the top layer of vegetation from the effects of freezing. Specialist training is also required for operators applying liquid nitrogen.
Leach J. & Dawson H. (2000) Is resistance futile? The battle against Crassula helmsii. Journal of Practical Ecology and Conservation, 4, 7-17.