Beat the Fungi: Coriander Health Quiz Quiz

Sharpen your knowledge of coriander disease management, exploring key identification tips and control strategies for a healthy harvest. Discover essential approaches to address common threats faced by coriander crops.

1. Identifying Damping-off in Coriander Seedlings

   A coriander grower observes that young seedlings are wilting and have water-soaked, soft stems near the soil line. Which disease is most likely responsible?

   1. Leaf spot
   2. Damping-off
   3. Powdery mildew
   4. Downy mildew

   Explanation: Damping-off is characterized by soft, water-soaked stems and sudden collapse of seedlings. Leaf spot usually causes defined lesions on leaves, not stem collapse. Downy mildew primarily affects older foliage, showing yellow patches and fuzzy growth. Powdery mildew leaves distinctive white, powdery patches, mainly on mature leaves.

2. Control Measure: Chemical Application Timing

   When applying fungicides to manage powdery mildew in coriander, what is the best practice for timing the spray?

   1. During seed storage
   2. At the first appearance of symptoms
   3. After harvest is complete
   4. Only before sowing

   Explanation: Early application at symptom onset helps limit disease spread and protect healthy plants. After harvest, spraying is not effective since the crop is already mature. Treating before sowing does not control powdery mildew on growing plants. Seed storage treatments target seed-borne diseases, not foliar infections.

3. Cultural Practices for Disease Prevention

   Which cultural practice can help prevent the buildup of soil-borne pathogens causing root diseases in coriander fields?

   1. Planting coriander repeatedly in the same spot
   2. Frequent overwatering
   3. Heavy use of nitrogen fertilizers
   4. Rotation with non-host crops

   Explanation: Rotating with non-host crops breaks pathogen cycles, reducing disease pressure. Overwatering can encourage disease development rather than prevent it. Repeating coriander planting increases pathogen risk, and excess nitrogen may lead to lush, disease-susceptible growth.

4. Downy Mildew Symptoms in Coriander

   What is a typical symptom of downy mildew in coriander plants during humid weather?

   1. Raised, corky lesions on seeds
   2. Entire plant bleaching immediately after germination
   3. Yellowish leaf spots with grayish, downy growth on lower surfaces
   4. Brown stem cankers with gum exudate

   Explanation: Downy mildew typically shows as yellow spots on leaves with grayish fungal growth below. Brown cankers and gum are symptoms of different diseases affecting stems. Corky seed lesions are unrelated to common foliar diseases. Plant bleaching after germination is indicative of damping-off, not downy mildew.

5. Seed Treatment Importance

   Why is seed treatment recommended for coriander before sowing?

   1. To fertilize the soil directly
   2. To reduce seed-borne pathogens and improve germination
   3. Because it speeds up flowering
   4. To repel leaf-feeding caterpillars

   Explanation: Seed treatment targets pathogens carried on or within seeds, preventing early disease and helping uniform germination. It does not directly fertilize the soil, hasten flowering, or protect against above-ground insect pests such as caterpillars.