Dothistroma Needle Blight of Pines

Causal Agent: Mycosphaerella pini (perfect), Dothistroma pini (imperfect)

Hosts: Over 30 species of pines, including Austrian, ponderosa, mugo, slash, Japanese black, and loblolly pines.

Symptoms: Symptoms develop in the fall of the year in which the infection was initiated. Early symptoms consist of yellow and tan spots, and water-soaked bands on the needles. The bands and spots may turn brown to reddish brown and may be surrounded by yellow bands. The tip of the needle beyond the red band eventually turns brown while the needle base remains green. The dead portion of the needle may break off leaving a blunted tip. Extensive damage may occur on the needles within 2-3 weeks on the initial symptoms. Within a few weeks after the needles die, small black fruiting structures of the fungus break through the outer needle tissue. Infected needles drop prematurely, with the lower branches usually showing early loss of needles first.

Control: Please contact your local county extension office for current information.

Return to Main page