![]() ![]() Needles may develop extensive necrosis 2 to 3 weeks after the first symptoms appear. ![]() Symptoms of Dothistroma blight on needle.Īlthough the bases of infected needles remain green, the ends of infected needles usually turn pale green, then yellow, and finally brown. Needles on lower branches of Austrian pine affected with Dothistroma blight.įigure 4-3. These reddish bands are most distinctive on pines in the West, where this disease is often referred to as "red band" disease.įigure 4-2. The spots and bands on the needles turn brown to reddish brown (fig. Look for yellow or tan spots and deep-green bands. In the Central States, symptoms develop in the faIl (October or later) of the year that the needles are infected. On established pines, infection is most severe on the needles in the lower crowns (fig. These epidemics have resulted in unmerchantable Christmas trees, reduced effectiveness of windbreaks, and increased maintenance costs in park and landscape plantings. In plantations in the Central States, however, epidemics have developed within 5 years of outplanting with infected nursery stock. Scirrhia pini), the sexual state of the fungus, has been found only in Alaska, Oregon, and California.ĭothistroma needle blight does not seriously damage pine seedlings in nurseries. The fungus occurs in 21 States, including Alaska (fig. The most frequent hosts are Austrian, mugo, and ponderosa pines in the Central and Eastern States and lodgepole, Monterey, and ponderosa pines in the West.įigure 4-1. pini), affects 20 pine species and hybrids in the United States. 680, 184 pp.ĭothistroma needle blight, caused by the fungus Dothistroma septospora (syn. USDA Forest Service, Agriculture Handbook No. See UW-Extension Bulletin A2620, or contact your county Extension agent.Glenn W Peterson - Plant Pathologist (retired), Rocky Mountain Forest and Range Experiment Station, USDA Forest Service, Lincoln, NE.Ĭordell C.E., Anderson R.L., Hoffard W.H., Landis T.D., Smith R.S. If you have established trees that are suffering from Dothistroma needle blight, remove fallen needles from around the base of these trees as these can serve as a source of fungal spores.įor more information on Dothistroma needle blight: ![]() ![]() Be sure to provide adequate spacing between trees to ensure good airflow and promote rapid needle drying. When planting new trees, make sure they are disease-free. Use white or Black Hills spruce, or white fir instead. How do I avoid problems with Dothistroma needle blight in the future?ĭo not plant Austrian pines as they are extremely susceptible to Dothistroma needle blight. Seedlings ( 40% of the crown affected) may not survive and should be removed. Young trees are more likely to suffer damage than older trees. The tip of the needle beyond the band eventually dies leaving the base of the needle alive and green. The spots become tan, yellow, or reddish-brown, and may encircle the needles to form bands. What does Dothistroma needle blight look like?ĭothistroma needle blight first appears as dark green, water-soaked spots on the needles. In Wisconsin, Austrian pines are most commonly and severely affected by this disease. Jim Olis* and Brian Hudelson, UW-Madison Plant Pathology *Completed as partial fulfillment of the requirements for a BS in Plant Pathology at the University of Wisconsin Madison.ĭothistroma needle blight is a common needle disease that can affect over thirty species of pine trees. Browning of needles typical of Dothistroma needle blight. ![]()
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