Biological Attacks Used to Curb Kudzu

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