Project Description
Sirococcus Tip Blight
Sirococcus shoot blight, caused by the fungus Sirococcus strobilinus, affects conifers in the Northern United States and southern Canada. The fungus infects the new shoots; diseased seedlings and saplings are especially affected. Trees that do not die often become misshapen. On older trees, the lower branches are often killed as a result of multiple infections. The fungus causes shoot dieback and stem and branch cankers on the current year’s growth. The needles on the infected shoot turn yellow and brown at the base; then entire needles die and turn brown. On most species, the shoots will often curl. As the fungus spreads into the shoot tissue, it causes a canker. Cankers on some species are purplish. A small drop of resin, or pitch, is often exuded at the base of infected needles. The tissue underneath the bark is resinous. Spray treatments can help if timed at budbreak.
