Tree disease problems

Dothistroma needle

4. Dothistroma needle

One of the most common fungal diseases of pines in Nebraska is Dothistroma needle blight. This disease is responsible for much of the premature needle drop that occurs in windbreaks and ornamental pine plantings. Twenty pine species are affected by this disease, but in the central and eastern United States the fungus is found most commonly and causes the greatest amount of damage on Austrian and Ponderosa pine. Scotch pine is usually not severely damaged.

Symptoms of infection begin in the fall. Yellow or tan spots appear on needles of the current year's or older growth. These spots darken and become brown or reddish-brown then spread to form a band around the needle. These bands are often bordered by a yellow, chlorotic ring on each side. The fungus grows within these tissues, killing that portion of the needle beyond the lesion.