Preventative measures: A Risk Assessment of
Cenchrus clandestinus (Pennisetum clandestinum) for Hawai‘I and other Pacific islands was prepared by Dr. Curtis Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service. The alien plant screening system is derived from Pheloung et al. (1999) with minor modifications for use in Pacific islands (Daehler et al. 2004). The result is a score of 18 and a recommendation of: "Likely to cause significant ecological or economic harm in Hawai‘I and on other Pacific Islands as determined by a high WRA score, which is based on published sources describing species biology and behaviour in Hawai‘I and/or other parts of the world."
A Risk assessment of
Cenchrus clandestinus (Pennisetum clandestinum) for Australia was prepared by Pacific Island Ecosystems at Risk
(PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score
of 12 and a recommendation of: reject the plant for import (Australia) or species likely to
be a pest (Pacific).
Physical: Difficult to dig out as all rhizomes must be removed to prevent resprouting (PIER, 2003).
Chemical: Roundup (without Pulse) 1%, Dowpon 740-SP (16-20 g/l sater), Gallant (0.5%) (Timmins & Mackenzie, 1995 in PIER, 2003)
For large areas, graze or mow kikuyu grass right down before spraying the new growth with Roundup while it is still short. For areas that contain desirable species, spray with Gallant (Environment BoP, 2003). The application of methylarsonic acid (MSMA) and triclopyr may reduce the competitive ability of C. clandestinus, allowing desirable species to reestablish (Cudney et al. 1993 in Haubensak & Smyth, 1999).
Biological: A rust fungus (Phakopsora apoda) has become established in South Africa, but it appears to only decrease the photosynthetic capacity of the leaves and does not kill the plant (Adendorff & Rijkenberg, 1995 in Haubensak & Smyth, 1999). Two insect pests, Sphenophorus ventus vestitus and Herpetogramma licarsicalis, damage kikuyu grass in Hawai‘I (Cronk & Fuller, 1995 in PIER, 2003), and Mootooka et. al. (2002 in PIER, 2003) states that it is also susceptible to the yellow sugarcane aphid (Sipha sp.). Plants are also affected by a fungus disease caused by Pyricularia grisea, which kills seedlings (FAO, 2003).
Location Specific Management Information
Upper Rock Management Plan recommends that plants of this species close to the reserve boundary should be eradicated to prevent them invading the reserve. Also recommends legislation prohibiting growing or keeping this species in gardens and homes within the reserve (Perez and Bensusan, undated in Varnham, 2006).
Rangitoto Is. (North Island)
In 1995, a weed control programme was initiated on Rangitoto Island, with 72 weed species identified. These were split into three priority classes, each with a management objective. The long term aim for this species is control to zero density (no adult plants).
Management is difficult because it grows back rapidly
Wenderholm Regional Park
Kikuyu grass in sites to be planted with native species were sprayed with a glyphosate herbicide one year before the natives were planted. The dead grass formed a deep mulch which protected the young plants from wind and helped retain soil moisture. By the end of 2000, these plantings had formed a dense shrubland along the forest edges, which suppressed the kikuyu grass.
1. Daehler, C.C; Denslow, J.S; Ansari, S and Huang-Chi, K., 2004. A Risk-Assessment System for Screening Out Invasive Pest Plants from Hawaii and Other Pacific Islands. Conservation Biology Volume 18 Issue 2 Page 360.
Summary: A study on the use of a screening system to assess proposed plant introductions to Hawaii or other Pacific Islands and to identify high-risk species used in horticulture and forestry which would greatly reduce future pest-plant problems and allow entry of most nonpests.
2. Environment Bay of Plenty. 2003. Weeds in New Zealand.
4. IUCN/SSC Invasive Species Specialist Group (ISSG)., 2010. A Compilation of Information Sources for Conservation Managers.
Summary: This compilation of information sources can be sorted on keywords for example: Baits & Lures, Non Target Species, Eradication, Monitoring, Risk Assessment, Weeds, Herbicides etc. This compilation is at present in Excel format, this will be web-enabled as a searchable database shortly. This version of the database has been developed by the IUCN SSC ISSG as part of an Overseas Territories Environmental Programme funded project XOT603 in partnership with the Cayman Islands Government - Department of Environment. The compilation is a work under progress, the ISSG will manage, maintain and enhance the database with current and newly published information, reports, journal articles etc.
7. Swaziland's Alien Plants Database., Undated. Pennisetum clandestinum
Summary: A database of Swaziland's alien plant species.
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