Annosum root rot

Annosum root rot is a fungal infection that enters healthy stands by infecting freshly cut stump surfaces. This disease is particularly a problem in thinned pine plantations. Over time, the disease will produce a pinkish to violet stain on the butt log, indicating rot, and devastate the root system of individual trees. The fungus can spread from tree to tree through root contact or grafts. Annosum root rot produces conks, light gray to brown fruiting bodies along the base of the stump. These conks are often overlooked, since they may be below the litter layer or are not noticeable due to their inconspicuous color. Thinning crowns, short needles and unexplained needle fall are all secondary indicators of annosum root rot. Summer thinning can reduce the amount of stump infection. An application of borax on infected stumps will assist in limiting the spread of the disease, but the best way to prevent infection is to have soils tested prior to plantation establishment. The application of prescribed burns at least twice before thinning will help to reduce diseases on high-hazard soils.

For further information on annosum rootrot, visit the following link:

http://dnr.wi.gov/forestry/fh/annosum/pdf/AnnosumRPPM.pdf.