Thursday, December 20, 2007

Invasive Species kudzu visits southwest; decides to stay

I find it interesting that some stakeholders continue to ask, correctly, for the science behind and underlying an invasive species, or perhaps invasive species issues in general. Not being a scientist, I am condemned to rely on my senses which could of course could and do lead me wildly astray from time to time. Noting that kudzu has made it to Arizona, I wonder if we all could agree that it is an example of a invasive species, and if that is true, could we use some of its attributes to help catagorize some other invasive species. More importantly, how much of a geographic area does an introduced species have to cover before wde can agree it is a problem? This goes to the question of EDDR, early detection and rapid response. Imagine the cost benefits of removing kudzu before it ate the confederacy. This nicely spills over into defintions of native, alien, exotic, weed and harm of which I have previously written much/

ARIZONA WEED NOTES 11 Dec 2007 Phoenix, AZ

ARIZONA KUDZU – One year UpDate
[ By Dr. Ed Northam, Weed Biologist, University of Arizona
Cooperative Extension – Phoenix, AZ 602/470-8086 ext 339
]
In September 2006, Arizona’s first reported population of Kudzu
[ Pueraria montana (Lour.) Merr. ] was discovered in Huachuca
City, Cochise County.
During early October 2006, plant samples collected from that unusual, sprawling, densely leaved, woody vine, plus photos by Jeffrey Myers, AZ Dept. of Agriculture, was enough evidence for Dr. Ed Northam, Invasive Plants Program Manager, University of Arizona Cooperative Extension Office, Maricopa County to conclude that Arizona had a population of Kudzu. Dr. Kelly Steele (plant taxonomist, AZ State University Polytechnic) also confirmed the initial vegetative diagnosis. DNA sequence analysis of leaf samples from Huachuca City by Dr. Martin F. Wojciechowski, Associate Professor, ASU Tempe, School of Life Sciences, matched published Kudzu DNA sequences. Kudzu attracts attention from Arizona plant scientists and land managers because this foreign vine has demonstrated its ability to dominate and smother both land and vegetation. Mature pine trees, roadsides, telephone poles landscape plantings in southeastern states have been buried under Kudzu’s invasive
growth.

Because of Kudzu’s reputation as a biotic invader, AZ Dept. of Agriculture personnel initiated an eradication process when identification was completed. This control measure is based on
a new herbicide from Dow AgroSciences called Milestone VM. Vince Aguiar, Dow’s range and pasture vegetation specialist for Arizona provided weed management expertise for eradication treatments that began in November 2006. Milestone was applied to the Huachuca City Kudzu at a rate of 7 oz. per acre. This application was repeated in March and June 2007. Visual estimates in August 2007 indicated >97 percent of Kudzu biomass died as a result of those three treatments (see photos provided by Arizona Dept of Agriculture).
Even though the Kudzu infestation appears to be controlled, treatments are planned for 2008 to complete eradication and will continue until new shoots cease to emerge; then occasional monitoring is needed to insure none of the underground root reserves survive and clone new Kudzu plants. Need information on how to identify Kudzu, contact ( enortham@cals.arizona.edu ).

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