Challenge your understanding of common diseases affecting coriander crops with this focused, medium-difficulty quiz. Explore symptoms, causes, and management strategies essential for healthier horticultural yields.
A coriander farmer notices yellowing leaves with a purplish-grey fungal growth on the underside during humid conditions. Which disease is most likely affecting the crop?
Explanation: Downy mildew is characterized by yellowing leaves and purplish-grey fungal growth, particularly in humid weather. Powdery mildew usually shows white powdery spots rather than colored fungal growth. Bacterial blight causes water-soaked lesions, not fungal masses. Root rot affects roots and leads to wilting but doesn't produce visible leaf fungal growth.
White, powder-like patches appear on both surfaces of coriander leaves, eventually causing them to twist and dry. What disease is causing this symptom?
Explanation: Powdery mildew is known for white, powdery patches on leaves, which lead to leaf deformation. Damping-off affects seedlings and stems rather than mature leaves. Leaf spot shows small, dark spots, not powdery areas. Viral mosaic causes mosaic-like discoloration, not powdery residues.
During inspection, swollen, tumor-like galls are observed on the stems and petioles of many coriander plants. Which disease is this?
Explanation: Stem gall is characterized by tumor-like growths on stems and petioles caused by the fungus Protomyces macrosporus. Anthracnose causes dark, sunken lesions but not galls. Rust produces pustules, and leaf blight leads to large dead patches on leaves, not swellings.
Scattered, small, brown spots with yellow halos are found on coriander leaves. Which pathogen is most likely responsible?
Explanation: Cercospora leaf spot is known for brown spots with yellow halos on leaves. Downy mildew presents with pale yellow patches and fungal growth. Powdery mildew appears as white powdery patches. Root-knot nematode affects roots, not leaves.
To prevent seed-borne fungal diseases like damping-off in coriander, which management practice is most effective?
Explanation: Seed treatment with fungicides is effective against seed-borne fungi causing damping-off. Overhead irrigation can increase disease risk by creating moist conditions. Planting in heavy clay soils worsens drainage and disease incidence. Excess nitrogen may promote lush, disease-prone growth.