The potential distribution of N. tenuissima predicted from a climate profile of distributions in its countries of origin shows that its potential full extent could cover 14 million hectares including large tracts currently under use for grazing. Being unpalatable N. tenuissima has all the signs of becoming a seroius grazing weed with potential for widespread establishment. A map of the spread can be seen Glanznig, 2005b. Morfe et al. assessed and compared from the viewpoint of the community the likely economic outcomes of government's pro-active and reactive-type weed control strategies to avoid the long-term 'external' cost of serrated tussock (Nassella trichotoma and N. tenuissima infestation in Victoria. Their results concluded that the net economic benefits to the community of a pro-active strategy i.e., immediate eradication of N. tenuissima within five years, would be about $41 million to $102 million depending on the scenarios tested. On the other hand, in all scenarios tested, the cost to government of a reactive strategy i.e., suppressing serrated tussock within 20 years using chemical method alone outweighs the benefits to the community by about $260 million to $1140 million.
N. tenuissima is included in the First Schedule of the National Pest Plant Accord. All plants on the list are designated as Unwanted Organisms, and are banned from sale, propagation and distribution throughout New
Zealand. Please see National Pest Plant Accord for the complete list.
Northland Region (North Island)
Nassella tussock is considered to be a service delivery plant by the Northland Regional Council. Plants will be treated by a recognised method, at intervals that will ensure the infestations are controlled, reduced and eventually eradicated. Further to this requirement, service delivery pest plants are banned from sale, propagation and distribution.
Please see the Pest management for defintions of pest designation.
N. tenuissima is one of 24 State Prohibited Weeds in Victoria rated as highly invasive and a major threat to Victoria. The Department of Primary Industries (DPI) began action on the prevention of the establishment of the weed in 1998. Nurseries, which had sold the plant, cooperated in tracing them. Suspect plants are reported to the DPI office and flowering specimens sent to the herbarium for identification.
N. tenuissima should not be cultivated, propagated or sold. Existing plants in gardens and nurseries should be destroyed. Follow-up inspections should be undertaken to ensure there is no re-growth from seeds.
Waikato Region (North Island)
Nassella tussock and fine stemmed needle grass (Nassella trichotoma) and (N. tenuissima) are classified as an “Eradication Plant Pests” by Environment Waikato. Environment Waikato will directly manage and control it, as well as monitor the weed and providing identification and control information to the community.
Please see definitions for hierarchy of pest designations.
Environment Waikato (2005) management options include grubbing out small infestations before they flower and set seed and destroying them by burning. Larger infestations are treated annually with an appropriate herbicide before plants flower and set seed. Continued checking and treatment (prior to seeding) is needed for a number of years. Landowners are encouraged to re-vegetate treated areas with desirable plants (Environment Waikato, 2005).
Wellington Region (North Island)
A Collective Programme (with a total funding of $24,000) was carried out by the Greater Wellington Regional Council in 2003/2004 that involved various research programmes, including one for Nessella tenuissima (also known as Mexican feather grass or Nassella tussock). This also involved research on another invasive species Nassella neesiana (Chilean Needlegrass) and consisted of liasing with Australian researchers regarding progress toward agents for both pests. It also involved providing practical assistance to a researcher based in Argentina.
Please see the 2002 – 2022 Regional Pest Management Strategy Part II for pest management plans and defintions of pest designation.
3. Christman, S. 2004. Nassella tenuissima. Floridata Market Place
5. Department of Primary Industries State of Victoria, Australia, 2003. New State Prohibited Weeds proclaimed, Pest Plant and Animal Management News, Under Control, June 2003, Number 24, ISSN 1328-2425.
6. Environment Waikato, 2005. Nassella Tussock (Nassella trichotoma) and Fine Stemmed Needle Grass (N. tenuissima)
10. Groves, R.H., Boden, R. & Lonsdale, W.M. 2005. Jumping the Garden Fence: Invasive Garden Plants in Australia and their environmental and agricultural impacts. CSIRO report prepared for WWF-Australia. WWF-Australia, Sydney.
12. Morfe, T. A; Weiss, J; and McLaren, D. A., 2002. Economics of serrated tussock and Mexican feather grass in Victoria: Why we need to act now Plant Protection Quarterly. 17(3). 86-94.
13. National Pest Plant Accord, 2001. Biosecurity New Zealand.
摘要： The National Pest Plant Accord is a cooperative agreement between regional councils and government departments with biosecurity responsibilities. Under the accord, regional councils will undertake surveillance to prevent the commercial sale and/or distribution of an agreed list of pest plants.
Available from: http://www.biosecurity.govt.nz/pests-diseases/plants/accord.htm [Accessed 11 August 2005]