Brown Spot Needle Blight Affecting Pine Trees
Since
early spring, the Alabama Forestry Commission (AFC) has been receiving phone
calls from landowners and the public regarding pine needles suddenly turning
brown. Many of these calls have been coming from counties in the northwest and northeast
regions of the state. The culprit of the needle discoloration is believed to be
the fungal disease known as brown spot needle blight. To date the disease has
been confirmed in 36 of 67 counties in Alabama.
Historically,
this disease has only infected longleaf pines (Pinus palustris). Brown
spot needle blight can be killed using prescribed burns. However, this method
is only effective for longleaf pine seedlings. In the last few years, the
disease has also begun to infect loblolly pines (Pinus taeda) in young
and mature stands. The cause for this change in behavior of the disease has yet
to be determined, but it can be speculated that it may be a new sub-species
that has evolved from the original fungal pest.
The
first sign of infection is discoloration of the needles. Infected needles will
contain circular lesions with a brown spot surrounded by a yellow halo. Over
time, the infected area will turn brown with a dark red or dark green border.
The discoloration begins in the lower portion of the crown and moves up as the
disease spreads by rain and wind events. An easy way to identify the disease is
if the pine needles look as if they have been scorched by fire, even though there
has been no burn. This disease can reoccur over a couple of years and cause
mortality to infected pines.
If
you believe your pines are infected with brown spot needle blight and want
needles tested, please contact your local Alabama Forestry Commission office.
Laboratory tests can confirm the presence of the disease. Symptomatic needles
are collected and brought to the Forest Health Dynamics Laboratory at Auburn
University for confirmation.
The mission of the Alabama
Forestry Commission is to protect and sustain Alabama’s forest resources using
professionally applied stewardship principles and education, ensuring that the
state’s forests contribute to abundant timber and wildlife, clean air and
water, and a healthy economy.
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