|Table: Diagnosis and Control of Sphaeropsis Shoot Blight|
|Pest Identification||Host Plants||Damage Symptoms|
|Sphaeropsis Shoot Blight
Formerly known as
|In the Midwest, Austrian, Scotch, and ponderosa pines are the most susceptible species. Mugo, red, jack and white pines, and white fir are also hosts.||Stunted, straw-colored shoots with short needles.
Black, pimple-like spore producing structures at the base of infected needles, shoots and cones. Cankers (oblong, sunken areas) on branches or the main stem and associated olive-green discoloration of the resin-soaked wood beneath the bark.
|Inspect nursery stock carefully, and plant only healthy trees.
Look for stunted, straw-colored shoots and shortened needles in the spring.
Above mentioned symptoms anytime of the year.
Do not plant susceptible pine species on stress-prone sites. Do not plant susceptible pine species next to infected trees. Implement tree care practices that reduce tree stress. Mulch, watering during drought, and periodic fertilization may be helpful. Promote good air circulation by adequate tree spacing and weed control. Prune and destroy infected branches (during dry weather).
|Description and Life History|
Description: Kills current-year shoots on trees of all ages. Older twigs,
branches or main stems are damaged only if they are mechanically wounded or the
tree's natural defenses are impaired by environmental stresses, particularly
drought stress. |
Life history: The fungus overwinters in branch shoots, bark, cones or litter. Infective spores are released during wet weather in the spring and invade succulent shoots through intact epidermis and enter needles through stomata. The fungus also infects second-year cones. The fungus readily infects through fresh wounds caused by hail, ice and snow; freeze damage; insects or other agents.
Back to Diseases of Conifers