Alternaria Leaf Blight

Alternaria Leaf Blight Alternaria Leaf Blight 
Lesions on Carrot FoliageLesions on Carrot Foliage
Advanced Lesions Cause Foliar DeathAdvanced Lesions Cause Foliar Death
Alternaria Leaf BlightAlternaria Leaf Blight

HOSTS

  • Carrots
  • Parsley

DESCRIPTION

Alternaria Leaf Blight of carrots (Alternaria dauci) can cause severe damage to carrots crops. Foliar damage can reduce the number and size of harvestable carrots.  

BIOLOGY

Alternaria dauci occurs as spores on or within seeds. The spores are spread when conditions are wet, through wind or water. The fungus can survive on infected carrot debris in the soil, but will die when the debris decomposes.

SYMPTOMS

  • Seedling death  
  • Dark-colored lesions with yellow halos on foliage, crown, and roots 
  • Foliar dieback resulting in smaller carrots 

GENERAL MANAGEMENT

  • Use certified pathogen-free seed. 
  • Rotate carrots with unsusceptible crops.
  • Plow or till carrot debris into the soil after harvest.
  • Use carrot cultivars that are less susceptible to Alternaria pathogens. 
  • Use watering methods that reduce moisture on plant foliage 

FUNGICIDES

Coming Soon

 

 

 

 

 

 

 








Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.