Assess your understanding of common diseases in coriander and the best farming practices for managing them. Enhance your skills for healthier and more resilient coriander crops.
Which fungal disease commonly affects coriander plants, causing yellowing and wilting of leaves, especially in humid conditions?
Explanation: Powdery mildew is a prevalent fungal disease on coriander, often visible as a white powdery growth on leaves, leading to yellowing and wilting. Root rot primarily causes root decay rather than leaf symptoms. Leaf blight often leads to brown or black spots rather than widespread yellowing. Yellow vein mosaic is a viral disease, not fungal.
A coriander farmer wants to reduce the risk of disease spread in a field. Which practice is most effective for minimizing humidity-related diseases?
Explanation: Proper plant spacing improves air circulation, limiting excess moisture and disease development. Watering at night increases leaf wetness, promoting diseases. Excessive nitrogen may cause lush, susceptible growth but does not directly prevent diseases. Full shade can increase humidity, raising disease risk.
Which approach best describes integrated disease management (IDM) for coriander crops?
Explanation: IDM uses a combination of methods—including cultural, biological, and chemical controls—to effectively manage diseases. Exclusively using synthetic fungicides may increase resistance and is not comprehensive. Depending solely on rainfall or harvesting early does not constitute a full disease management strategy.
If powdery mildew appears on coriander, which practice ensures effective and safe fungicide application?
Explanation: Using fungicides at recommended doses and intervals is most effective and reduces risks. Doubling the dose can cause toxicity. A single late application may not control early outbreaks. Mixing incompatible chemicals can reduce effectiveness and cause crop harm.
What is a key symptom of bacterial leaf spot in coriander, and how does it differ from fungal diseases?
Explanation: Bacterial leaf spot is characterized by small, water-soaked lesions with yellow halos, distinguishing it from fungal diseases like powdery mildew (white coating) and root rot (root-specific wilting). Concentric rings generally indicate other pathogen groups.