With the short, mild weather of this past winter, it looks as
though weeds are getting a head start this spring. As for the south, the main
weed everyone dreads is the choking, enveloping kudzu vine. The invasive plant takes over just
about any field, climbs tall timbers and is a nuisance to eradicate.
Most landowners in states like Mississippi and Alabama have
done just about anything to eliminate the destructive plant. Though the vines are easy to mow or mulch,
the mechanical method doesn’t seem to be the most effective kudzu removal
technique. In fact, time spent plowing over the green foliage doesn’t expel the
root of the plant is likely wasted as surface sheering doesn’t expel the root
crown.
Biological Growth Control
Herbicides may be effective in the long run, but they
require dousing gallons upon gallons of chemical over a period of a few years
before results are successful. That cost adds up very quickly and can even affect
surrounding plants and groundwater sources. However, there are a few biological
attacks that arborists have attempted to parry the kudzu plant into submission.
Here are just a few new kudzu removal techniques that may be worth trying this
year.
Bacterial Blights
In the past, blights have caused detrimental damage to large
sources of crop plants including, potatoes, corn, tomatoes and apple
trees. Blights are naturally occurring
pathogenic organisms that affect plants through mold and other water-born
fungi. They affect plant tissue by
causing complete chlorosis, which is depriving the plant of essential
nutrients. Soon the plant tissue begins to brown and die. Applying blights in a
controlled manner to kudzu plants has been tested as a positive candidate for
biological growth control and ultimately utilized as kudzu removal.
Insect Herbivory
Insect herbivory is simply a method of introducing
controlled amounts of insects that are anatomically adapted to eating
particular plants. By applying this biological attack, specific insects are
encouraged to devour parts of the kudzu plant therefore causing significant
damage and even killing the plant. Because kudzu is a native plant to southern
Asia, and not to southern United States, there are few known insects that are
natural predators to the plant. Therefore, research is being conducted to find
the appropriate insects to use in controlling the growth and aiding in
eliminating the devastating kudzu vine.
Seed Predation
Similar to herbivory, seed predation is a biological method
of introducing natural predators to consume the kudzu plant. By consuming the
seeds of the plant, the insects not only chomp through the leaves and vines of
the plant, they interrupt the germination of the plant and alleviate the amount
of regrowth or spreading of the vine. So far, field tests have found that more
than twenty-five species of insects are feeding on the kudzu plant in areas of
North Carolina. Of these predators, the sawfly and several different
leaf-eating beetles were identified. The best thing about these predators is
that they have no known hosts.
With several different studies being conducted
across the southeast, there stands a forerunner as studies hone in on an
effective method of biological control. The fungal pathogen known as Mythrocium verrucaria has shown the best
results against kudzu vines. The fungus has been used as a pesticide on other
plants and grows well in temperatures matching those of the southeastern region.
The organism does not venture beyond the areas in which they are introduced,
keeping surrounding vegetation and bordering crops safe from consumption.
However, the one drawback is that the fungus is highly toxic to mammals.
Extreme caution must be used in applying this type of biological attack, which
is why it has not yet been released as an accepted kudzu removal strategy.
Hopes are that the pathogen can be applied in closely moderated areas.Photo courtesy: SweetCrisis
