 |
|
|
 |
|
|
|
|
|
Acacia farnesiana (tree, shrub)  |
|
|
Management Information
Preventative measures: A Risk Assessment of Acacia farnesiana 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 14 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."Physical: "Destroyed by cultivation and grubbing" (Swarbrick, 1997. In PIER, 2002). Although the aerial portions may be killed by fire, it soon
regenerates from basal shoots"" (Smith, 1985). Once established, the seedlings grow rapidly and resprout readily following damage or top removal. Acacia
farnesiana sprouts may grow to almost half their original total plant height within 5 months after shredding (Powell et al., 1972). Thus, mechanical top
removal results in only short-term suppression of A. farnesiana (Mutz et al. 1978) and gives the species competitive advantage over associated, slower
growing woody plants. Almost pure, dense stands of A. farnesiana may develop within two to three growing seasons following brush control methods that
disturb the soil.
Chemical: Probably susceptible to translocated herbicides, including picloram, metsulfuorn-methyl, glyphosate and triclopyr, and possibly 2,4-D applied to the foliage, freshly cut stumps or by stem injection at standard rates.
Also probably susceptible to residual herbicides, including tebuthiuron and hexazinone (Swarbrick, 1997 in PIER, 2002). "Sensitive to foliar applications of triclopyr at 1 lb/acre and metsulfuron at 0.45 oz/a and to basal bark applications of 2,4-D or triclopyr at 2% in diesel. Drizzle applications were not effective in foliar and basal bark trials at Kihei, Maui, but these trials were confounded by a severe drought" (Motooka et al. 2002. In PIER, 2002).
Location Specific Management InformationAscension Is. (Saint Helena)
The Management Plan suggests this species may become as harmful as Prosopis, with which it shares many similarities. It recommends mapping the distribution of this species as well as assessing its invasive potential and control methods (Pickup, 1999 in Varnham, 2006). French Polynesia (Polynésie Française) 
Decree No. 65 CM of January 23, 2006 presents a list of 35 invasive plants declared to be "Species that threaten biodiversity", one of which is Acacia farnesiana. These plants are subject to a ban on new imports, propagation and planting, and prohibition of transfer from one island to another of any whole plant, fragment of plant, cutting, fruit or seed. Marquesas Islands (French Polynesia (Polynésie Française))
Decree No. 65 CM of January 23, 2006 presents a list of 35 invasive plants declared to be "Species that threaten biodiversity", one of which is Acacia farnesiana. These plants are subject to a ban on new imports, propagation and planting, and prohibition of transfer from one island to another of any whole plant, fragment of plant, cutting, fruit or seed. Marquesas Islands (French Polynesia (Polynésie Française))
Legally declared a threat to biodiversity in French Polynesia (Meyer 1998). Meyer (2000) lists this species as a dominant invader of dry sites. Queensland (Australia)
The best time for treatment is during autumn when plants are actively growing and soil moisture is good. Basal bark spray: For stems up to 15 cm diameter, carefully spray completely around base of plant to a height of 30 cm above ground level. Thoroughly spray into all crevices. Larger trees may be controlled by spraying to a greater height, up to 100 cm above ground level. At any time of year, cut stems off horizontally as close to the ground as possible. Immediately (within 15 seconds) swab cut surface with herbicide mixture.
Management Resources/Links
2. 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. 5. Le Houérou. Acacia farnesiana (L.) Willd. Grassland Index. UN FAO.
Summary: Drawings, description, common names, habitat, soil, propagation, distribution, crop management, products and uses, links, references, photos.
Available from: http://www.fao.org/ag/AGP/AGPC/doc/Gbase/DATA/Pf000113.HTM [Accessed on 10 October 2002]. 6. Motooka, P., L. Castro, D. Nelson, G. Nagai and L. Ching . 2002. Weeds of pastures and natural areas of Hawaii and their management. In press. Results Page: 1
|
|
|
|
 |
|
