Leaf spots—Cercospora carotae and Alternaria dauci
Leaf spots can occur on any carrot tissue above ground. However, symptoms are usually most severe and
obvious along leaflet margins. Infection sites initially appear as a brown or black spot with a yellow
margin. As the disease progresses, the leaflets become yellowed and curl at the margins. Lesions on leaf
petioles, stems, and flower parts are usually elongated and dark brown.
Cercospora and Alternaria leaf spots are favored by moist conditions. The fungi are seedborne but can
be spread by wind and splashing water. Keep foliage dry and avoid overhead sprinklers. Remove infected
plants, and destroy diseased crop material by plowing it under to ensure decomposition. Some varieties
may show resistance.
leaf spot on carrot leaves