Explore key diseases affecting coriander crops and learn how to identify, differentiate, and manage common fungal threats in agricultural settings.
A coriander farmer notices white, powdery patches on the upper surfaces of leaves during cool, humid weather. Which disease is most likely affecting the crop?
Explanation: Powdery Mildew typically appears as white, powdery spots on leaves, especially in humid conditions. Root Knot Nematode causes root galls but not white patches. Bacterial Leaf Spot produces water-soaked lesions, not powdery growth. Downy Mildew shows yellowish patches and grayish growth on the underside, not white powder on the upper surface.
Which fungal disease causes coriander seedlings to wilt, collapse at the soil line, and die shortly after germination?
Explanation: Damping-Off is a soil-borne disease leading to stem collapse near the soil surface in young seedlings. Leaf Blight mostly affects mature leaves. Sclerotinia Rot causes white mold on stems and pods but not immediate seedling death. Rust shows as pustules, not seedling collapse.
A coriander field develops soft, water-soaked lesions and cottony fungal growth at the base of plants, often leading to lodging. Which disease does this describe?
Explanation: Sclerotinia Stem Rot shows as water-soaked stem lesions and white, cottony fungal growth, leading to plant collapse. Verticillium Wilt causes yellowing and wilting but not cottony growth. Septoria Leaf Spot creates small leaf spots. Alternaria Blight results in brown spots, mainly on leaves.
If a coriander plant exhibits circular reddish-brown spots with gray centers on its leaves, which disease should be suspected?
Explanation: Alternaria Blight causes characteristic reddish-brown spots with gray centers on leaves. Powdery Mildew appears as white patches, not spots. Fusarium Wilt leads to yellowing and wilting without distinct spots. Cercospora causes leaf spots, but they are often brown with defined margins, not gray centers.
In coriander cultivation, which agricultural practice can help reduce the risk of fungal diseases spreading from plant debris in the field?
Explanation: Crop Rotation helps break disease cycles by removing the host for pathogens in successive seasons. Increased Irrigation may promote fungal growth. Overcrowding seeds raises humidity, encouraging disease. Watering in the early morning helps foliage dry faster, but crop rotation more directly breaks transmission.