Do Not Prune Oaks--Avoid Spreading Oak Wilt

Red oaks are very susceptible to oak wilt. New infections occur in spring, and symptoms develop in summer. (Photo: Joseph O'Brien)

ST. PAUL, Minn.--The onset of the "high risk period" for overland transmission of oak wilt disease will arrive soon. Oak trees are at high risk when oak wilt fungal mats are present on trees killed the previous year by the disease and when nitidulids (sap-feeding beetles) are active. The onset of high risk occurs earlier as you go farther south and varies with weather conditions. The "rule of thumb" for the Upper Midwest is to avoid pruning or wounding oaks during the months of April, May, and June. Nitidulids, carrying spores of the fungus, can be attracted to fresh wounds on oak trees. When visiting these wounds, nitidulids can transfer spores to the oaks, initiating oak wilt disease infections.  To avoid infection, all wounds to oak in the spring should be treated immediately with wound dressing or paint. New symptoms of oak wilt disease usually are apparent in July and August. More information can be found in the publication How to Identify, Prevent, and Control Oak Wilt.

White Pine Blister Rust a Renewed Threat  

DURHAM, N.H.--Forest pathologist Isabel Munck completed a study showing that white pine blister rust is again threatening white pines in New Hampshire, due to a breakdown of resistance on host Ribes culti­vars that were previously labeled as resistant to the disease. The paper, Impact of white pine blister rust on resistant cultivated Ribes and neighboring eastern white pine in New Hampshire, is available online in the journal "Plant Disease."  

Planning and Managing for Emerald Ash Borer   

Emerald ash borer larva and galleries. (Photo: James W. Smith, USDA APHIS PPQ, Bugwood.org)

Researchers from the U.S. Forest Service are trying to find ways to save northern Minnesota from the emerald ash borer (EAB) and its voracious appetite for ash trees. Minnesota possibly has more ash trees than any other State. Listen to a 4-min audio version of the story on MPRnews online. Also see the EAB success story from Minnesota in this newsletter.

To learn how Pennsylvania is managing ash trees, view a recorded EAB Webinar hosted by Michigan State University and given by Don Eggan with the Pennsylvania Bureau of Forestry.

For more information on EAB, visit www.emeraldashborer.info--a Web site developed in cooperation by several universities, States, and the U.S. Forest Service and Animal and Plant Health Inspection Service.

Soils Support Agriculture

Hear Soil Scientist Roger Windhorn of the Natural Resources Conservation Service talk about why you should know your soil, in the 7-minute video, Know your dirt on You Tube. Explore the various types of soil in Dig It: the Secrets of Soil on the Smithsonian Institution's Web site.

Future of Forests at Risk Symposium, April 25

 Mid-Atlantic Wildfire Training Academy, June 6 - 12

MORGANTOWN, W.Va.--West Virginia University will host the ninth annual Mid-Atlantic Wildfire Training Academy, June 6-12, 2015, in Morgantown. The academy will offer a suite of courses in essential wildland firefighting skills, from basic to advanced. Upon successful course completion, students will receive certificates from the National Wildfire Coordinating Group. Some courses require pre-course work. Register on the Mid-Atlantic Forest Fire Compact Web site. The academy is presented by the Mid-Atlantic Forest Fire Compact, the West Virginia University Division of Forestry and Natural Resources, and the USDA Forest Service.

Outreach for Secretary, Cooperative Fire and Aviation Management