Septoria Leaf Spot - Septoria musiva
Septoria Leaf Spot lesions
Minnesota Dept. of Natural Resources Archives
Minnesota  Dept. of Natural Resources, www.ipmimages.org

HOSTS: Vegetables, flowers, woody species such as aspen, cottonwood, poplar, maple, and dogwood.

DESCRIPTION: On annuals, symptoms first appear as sunken, black flecks. Lesions develop into circular spots with tan centers and dark margins. On woody species spots coalesce to form dead blotches.

LIFE CYCLE: This disease is favored by wet weather and temperatures of 72 - 79° F.

CONTROLS:
Vegetables: Use resistant cultivars. Remove and destroy infected leaves. Use 1 – 2 year rotations. Stake annuals for better air circulation. Keep irrigation water off of leaves. Sulfur applications during warm wet weather may reduce infection.
 
Woody Plants: Rake and destroy infected leaves in the fall. Apply sulfur during warm, wet spring weather.


Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006