Fungus Looks Like Promising Weapon Against Invasive Tree
Ailanthus, a nonnative invasive tree from Asia, is a prolific sprouter that is difficult to control with herbicides or cutting. However, there may be an alternative control method in the near future. In 2002, Penn State researchers isolated the fungus Verticillium nonalfalfae from dead and dying ailanthus trees within forested areas of Pennsylvania. After much rigorous testing and numerous trials, this soil-borne fungus was found to be very specific and deadly to ailanthus. In 2008, the same fungus was also found in Virginia and in 2012 Forest Service scientists isolated it Ohio. In 2013, they began greenhouse tests to verify that native tree species are not susceptible to the fungus. Preliminary tests on seedlings from native Ohio seeds of ash, beech, elm, and oak (black, chestnut, northern red oak and white) are encouraging---no signs of wilt were observed. Inoculation field trials in Ohio forests are planned for early summer 2014. There are three great advantages to using this fungus: the fungus is a native species; the fungus can spread from tree to tree through root grafting and naturally build-up, so that not every ailanthus stem in a stand needs to be treated; and, the fungus specifically kills ailanthus and it can survive in the soil for many years.
Forest Service Partners