Which genus is associated with Alternaria Leafspot on cole crops?

Which genus is associated with Alternaria Leafspot on cole crops?

• A. Alternaria
• B. Phytophthora
• C. Pythium
• D. Botrytis

Answer: (A)

The disease name itself points to the attacking organism. Alternaria leaf spot on cole crops is caused by fungi in the genus Alternaria (for example, Alternaria brassicicola or Alternaria brassicae), which is why this genus is associated with the disease. On cabbage, broccoli, and other brassicas, you’ll see small to circular brown spots on the leaves that can enlarge, sometimes developing a grayish center with a dark border as conditions stay warm and humid. These fungi spread by spore production on moist surfaces and can defoliate plants if conditions remain favorable. The other genera listed cause different problems: Phytophthora and Pythium are mainly water-mlogged soil and seedling/root diseases, not the classic leaf spot associated with Alternaria; Botrytis (gray mold) causes a fuzzy gray mold on leaves and other tissues rather than distinct Alternaria leaf spots. So the genus tied to Alternaria Leafspot on cole crops is Alternaria.

The disease name itself points to the attacking organism. Alternaria leaf spot on cole crops is caused by fungi in the genus Alternaria (for example, Alternaria brassicicola or Alternaria brassicae), which is why this genus is associated with the disease. On cabbage, broccoli, and other brassicas, you’ll see small to circular brown spots on the leaves that can enlarge, sometimes developing a grayish center with a dark border as conditions stay warm and humid. These fungi spread by spore production on moist surfaces and can defoliate plants if conditions remain favorable.

The other genera listed cause different problems: Phytophthora and Pythium are mainly water-mlogged soil and seedling/root diseases, not the classic leaf spot associated with Alternaria; Botrytis (gray mold) causes a fuzzy gray mold on leaves and other tissues rather than distinct Alternaria leaf spots. So the genus tied to Alternaria Leafspot on cole crops is Alternaria.