Text 23283, 149 rader
Skriven 2007-11-22 22:56:00 av JIM WELLER (1:123/140)
     Kommentar till en text av GLEN JAMIESON
Ärende: Re: KUDZU   71122
=========================
-=> Quoting Glen Jamieson to Jim Weller <=-

 GJ> I can probably be thankful that, as far as I know, we don't have the
 GJ> dreaded kudzu in Australia

In queensland apparently.

 GJ> one method of biological control would be goats.

Yep.

Some factoids from Columbia University www.columbia.edu

Identification: A high climbing, trailing, twining deciduous woody
vine, kudzu can be seen blanketing forests, abandoned houses, and
whatever else might remain in its path. The roots are tuberous and
rope like, and the hairy stems can grow to 20 meters in length.

Original Distribution: In Asia temperate kudzu is found in China,
Japan, Korea, and Taiwan. In asia tropical kudzu is in Indonesia,
Malaysia, Papua New Guinea, Philippines, Thailand, and Vietnam.
Kudzu is also native to Queensland, Australia and, in the Pacific,
Fiji, New Caledonia, Solomon Islands, Tonga, and Vanuatu. 

Current Distribution: Kudzu is estimated to cover 810,000ha
(2,000,000 acres) across southern United States alone. Though
normally found only south of New York and east of Texas (area in
map), populations have been found as far north as Nova Scotia and
and northwest as Oregon. It has also invaded Puerto Rico and South
Africa. 

Site and Date of Introduction: Kudzu was first introduced to the
United States in 1876 at the Centennial Exposition in Philadelphia,
Pennsylvania. The Japanese constructed a beautiful garden filled
with plants from their country, and American gardeners quickly
started using the plant for ornamental purposes. 

Mode(s) of Introduction: In the 1920s, Florida nursery operators
Charles and Lillie Pleas discovered that animals would eat the kudzu
and promoted its use as forage. In the 1930s, the Soil Conservation
Service employed hundreds of young men in the Civilian Conservation
Corps to plant the vine for erosion control.  In the 1940's, the US
Government paid farmers as much as 8 dollars per acre of vine they
planted. 

Reason(s) Why it has Become Established: Besides escaping native
insect predators, the climate of the Southeastern US is perfect for
kudzu. The vines grow as much as one foot per day during summer
months, climbing anything from trees to power poles to abandoned
buses. In addition, kudzu is an extremely hardy plant. It is drought
tolerant and frost only harms its above ground portions. The thick
storage roots, which form from stem nodes touching the ground, can
grow as deep as one meter. They also have a high starch content that
allows the plant to grow early in spring and regrow if the vines are
damaged in the summer.  Flowering in late summer and early fall,
kudzu produces a large amounts of seeds which are dispersed by birds
and mammals. 

Ecological Role: Kudzu controls erosion, fixes nitrogen, and can be
used as a starch or vegetable for humans. In addition, its chemical
composition and digestibility make it suitable as a fed forage for
animals such as cattle and sheep. For example, the percentage of
crude protein in its leaf and stem is comparable to that in lucerne
and bermudagrass hays.

Benefit(s): Growing fast and with a strong root system, kudzu is
excellent for erosion control. The plant also has agricultural uses.
The plant fixes nitrogen and can be used as a feed for pasture
animals. Kudzu contains several medical chemicals such as daidzen,
used to fight inflammation and microbial infections, dilute coronary
arteries, relax muscles, and promote estrous cycles. It also
contains daidzin, which is used to prevent cancer, and genistein, an
anti-leukemic. Several people throughout the south have found that
kudzu's rubber-like vines are excellent for making basket weaving
and artistic paper. Others incorporate it in their diet, cooking
such things as kudzu quiche and deep-fried kudzu leaves.   

Threat(s): Kudzu has and continues to smother forests in the south-
eastern United States by preventing them from getting sunlight and
breaking them under the weight of its vines.  Some forests have been
strangled in as little as two to three years. Kudzu also threatens
riparian areas and watershed health. Spreading about 120,000 acres a
year, control costs for the vine increase by nearly $6 million each
year. The spread of kudzu results in a lowering of land
productivity, biodiversity, and economic losses in the timber
industry. 

Control Level Diagnosis: Highest Priority-Attempts to control kudzu
must be continued and enhanced. The vine already covers a huge area
and is continuing to spread rapidly.

Control Methods: 

Mowing: Only repeated mowing can weaken and control kudzu. Though
it can be a first step toward control, significant risks are
involved. Kudzu can conceal ditches and the thick mats of vines can
be difficult to cut with a light duty rotary mower. Flail mowers
with horizontal blades that cut in a chopping manner are more
effective. If done, close mowing makes the treatment of regrowth
much easier, reducing the tangle of leaves and vines. 

Grazing: The prospect of using kudzu for grazing was a reason for
its planting in the US. Indeed, the plant is comparable in
nutritional value and digestibility to other commonly used forages.
To control kudzu by grazing, though, it is necessary to fence in the
entire patch. Only by repeatedly grazing growth over several seasons
will the root stores be depleted. Such grazing projects are already
underway. As of September 2001, 600 sheep were gnawing kudzu in
Tallahassee, Florida and dozens more were dining in smaller sites
around New England. Also, Dr. Errol G. Rhoden, with researchers at
Tuskegee University, is raising Angora goats in fields of kudzu.
While keeping the vine from spreading further, the goats also
produce milk and wool products. Rhoden says a constant grazing will
eventually eradicate the kudzu. 

Burning: Controlled burning can be used so that a site can be
inspected to determine the size and density of the root crowns.
However, burning should be done in either winter or spring, with
spring the more desirable as to limit the exposure of the bare soil
to winter rains and limit soil erosion. 

Herbicides: Herbicides are a common and expensive option to control
of kudzu. Several herbicides are labelled for kudzu control, and
different ones are recommended depending on the the type of nearby
plant or tree that kudzu has covered. Some herbicides make kudzu
grow better and many have little or no effect. At least four years
of repeated treatments are recommended. Some kudzu takes as long as
ten years to kill, even with the most effective herbicide. 

Biological Control- In a recent experiment, Myrothecium verrucaria,
a fungus native to the Southeastern United States, has been found to
be an effective pathogen against kudzu grown in the greenhouse and
field. In addition, though the fungus, acquired from naturally
infected sickle pod, can produce toxins in a variety of substrates,
it does not in kudzu tissues. The results argue that the fungus can
be used safely as a biological control of kudzu and supports
proceeding to animal feeding trials for further evaluation of its
safety. 
          


Cheers

YK Jim


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