| Pitch canker seen
in Texas pine forest; pine beetle infestation low in
Ark-La-Tex By Jonathan Dingler Forest managers have little to fear this year from the infamous southern pine beetle. According to the Texas Forest Service, very few or no SPB infestations are expected for the Ark-La-Tex region in 2005. Another forest pest, however, is beginning to attract attention in the Piney Woods, especially in East Texas. It's a disease called pitch canker, caused by the pathogen Fusarium circinatum. The disease can cause die-back of branches and shoots leading to a general decline in tree health, and in severe cases, premature death. Although mortality is uncommon, timber value is decreased due to lost growth and stem deformities. Pitch canker has been a problem in the Southeast for some time, but was previously rare in Texas except in seed nurseries. The abundant rainfall for the region in 2004 is likely responsible for the increased distribution of the disease among pine plantations. Spread by airborne spores, the pathogen can be carried by wind and water as well as by native insects. Insects known to carry the disease include bark beetles, twig beetles, and pine weevils. Many of these insects are known to transmit the pitch canker fungus to healthy trees and are considered to be the primary means by which new infections are established. Although insects can spread the disease to new areas, long distance spread is more likely to result from humans transporting infected logs, nursery stock, seeds or soil. When trying to identify pitch canker, look for dead branch tips in the upper part of the tree canopy. Needles on the ends of these branches are either wilted, dead or absent, and resin flow is found at the point of infection on the branch. A more advanced symptom of the disease is the appearance of resinous cankers on the main stem and larger branches of the tree. For more information on what to do if pitch canker is found on your land, contact your local Forest Service office or cooperative extension agent. |